NBSIR 74-605

Crush Characteristics of Automobile

Structural Components

Donald C. Robinson

Engineering Mechanics Section

Mechanics Division

Institute for Basic Standards

National Bureau of Standards

Washington. D. C. 20234

January 1975

Final Report

Prepared for National Highway Traffic Safety Administration

Department of Transportation

400 7th Street, S.W.

Washington, D. C. 20590

NBSIR 74-605

CRUSH CHARACTERISTICS OF AUTOMOBILE

STRUCTURAL COMPONENTS

Donald C. Fiobinson

Engineering Mechanics Section

Meciianics Division

Institute for Basic Standards

National Bureau of Standards

Washington, D. C. 20234

January 1975

Final Report

Prepared for National Highway Traffic Safety Administration

Department of Transportation

400 7th Street, S.W.

Washington, D.C. 20590

U. S. DEPARTMENT OF COMMERCE. Frederick B. Dent. Secretary

NATIONAL BUREAU OF STANDARDS. Richard W. Roberts. Director

CONTENTS

Page

1. INTRODUCTION 1

2. DESIGN OF SIMULATED BUMPER 2

3. UNIVERSAL TESTING MACHINE 3

4. VEHICLE SUPPORT FRAME 3

5. TEST VEHICLE PREPARATION 4

6. STATIC TEST PROCEDURES 4

6.1 Alignment of Simulated Bumper 4

6.2 Instrumentation of Test Vehicles 5

6.3 Measurement Procedure 5

7. DYNAMIC TEST PROCEDURES 6

7.1 Modification of Bumper 5

7.2 Instrumentation for Dynamic Test 7 7.3 Measurement Procedure 8

8. ANALYSIS OF DATA 10

8.1 Static Crush Tests 10

8.2 Dynamic Crush Tests I7

9. COMPARISON OF STATIC AND DYNAMIC TESTS RESULTS I9

10. CONCLUSIONS AND RECOMMENDATIONS 20

11. ACKNOWLEDGEMENTS 21

12. REFERENCES 22

Crush Characteristics of Automobile

Structural Components

Donald C. Robinson

ABSTRACT

Static and dynamic test procedures were developed for evaluating the crush characteristics

of automotive structural components which perform

a major structural function in side impacts. Laboratory tests were conducted on several 1969 to

1971 4-door intermediate size automobiles to evaluate

the crush characteristics of some of their structural

components. Static crush tests were conducted

in the 12-mil 1 ion-lbf capacity universal testing

machine at the National Bureau of Standards, em- ploying its large working space. The dynamic tests were conducted using the monorails attached to

the sensitive crosshead and the tie-down floor

system which is incorporated in the foundation

of this machine. The crush loads were applied

perpendicular to the vehicle side for each of

the tests. The response of the structural components

was established based on the evaluation of displacement

and/or strain measurements and detailed examination

of the permanently deformed components following

each test. Empirical factors were obtained which

are useful for comparison of static and dynamic

crush characteristics of a vehicle side door structure over a limited loading range. Further development of the test procedures is required in order

to extend the range over which such results would

be meaningful.

Key Words: Automobile side impact, crush characteristics, displacement measurements, door structure,

drop tests, dynamic crush tests, impact collisions,

plastic deformation, static crush tests, strain

measurements, structural components, test procedures.

1. INTRODUCTION

Automobile collisions in which loads are developed that result

in permanent deformation of a vehicle side structure account for a
significant number of injury producing accidents each year [l, 2j.

Accident data reveal that side impacts are more severe in causing

dangerous or fatal injuries than other accident types. The objective

of the research described in this report was to develop methods for

evaluating the crush characteristics of the principal components which

perform a major structural function in a vehicle whose side is struck

by another vehicle.

While emphasis was placed on developing laboratory procedures

for characterizing the static and dynamic crushing of various struc-

tural components, the data obtained from a limited number of tests

provide additional general information which may be useful in the

development of computer simulation programs for vehicle side impacts.

The component crush characteristics are given in terms of load-deformation relationships and, for several cases, in terms of the relative

deformation between members. Analyses of the static test data indicate

significant structural degrees of freedom for various components.

The regions of localized plastic deformation for the components are identified and some insight is provided into the sequence in which

forces are developed in various members duritig application of the

crush loads.

The static and dynamic loads applied to two vehicles, which were identical in design and similar in condition, were correlated at se- lected values of their side door deformation. En5)irical factors which

were obtained are useful for comparison of the static and dynamic

crush characteristics of a vehicle side door structure over a limited

loading range. Further development of the test procedures required

to extend the range of these factors is discussed, and recommendations

for obtaining similar results for additional components are made.

In accordance with NBS policy, the brand names of commercial

products tested are not given in this report. Consequently the three

vehicles tested are identified by the letters A, B and C.

2. DESIGN OF SIMULATED BUMPER

In order to evaluate the crush characteristics of the automotive

structural members which perform a major function during side impact

collisions, a contoured bumper was fabricated to simulate the front

of an impacting vehicle. A review of the crashworthiness research

literature indicated that the basis existed for the design of a realistic bumper which could provide a repeatable test technique [l, 2j.

The configuration chosen was designed so that no permanent deformation

would occur in its members during static or dynamic crush tests.

[I J.Numerals in brackets refer to references found at the end of this re- port.
The simulated bumper used for the static crush tests is shown

in Figure 1. This design is essentially identical to that specified

in the Society of Automotive Engineers (SAE) recommended practice

for moving barrier collision tests, insofar as the contoured face

is designated [3j. The SAE design was based on deformation considerations

and observations of a wide range of side impacts from a wide range

of vehicles. The support structure was designed so that all parts

of the loading system would be rigid with respect to the structure

to be crushed so that no yielding would occur in its components. The

weight of the bumper in this configuration was about 800 lb (363 kg).

3. UNIVERSAL TESTING MACHINE

In order to apply the static crush loads to the vehicle side

structures, it was decided to employ the 1 2-mi 1 1 ion-1 bf capacity universal testing machine at the National Bureau of Standards because

of its large working space [4j, A photograph of this machine is shown

in Figure 2. The simulated bumper described in the previous section

was attached to the sensitive crosshead of this machine for the static

tests, during which the vehicle support frame was attached to the

machine platen. For the dynamic tests, it was found convenient to use the monorails attached to the machine sensitive crosshead from

which to drop the bumper onto the vehicle side. The vehicle

support frame was attached to the tie-down floor system which is incorporated in the foundation of this machine during the drop tests.

4. VEHICLE SUPPORT FRAME

In order to support the vehicles in the testing machine during

static tests and on the machine tie-down floor for the drop tests,

it was necessary to construct a frame structure for a vehicle so it

could be oriented perpendicular to its usual position. The test frame was constructed using 12 inch steel I-bcams which were reinforced

by welding steel plates where the beams joined. Subsequent to the

first several tests, the stiffness of several members was increased

by welding additional plates to their flanges and improving the connections in order to support larger test loads.

The principal considerations for connecting the support frame

to the vehicle were that it be rigid and not alter the characteristics

of the side structural members being tested [5j. Consequently, the

frame was attached to the vehicle underbody near the engine mounts

and near the trunk. Because of the relatively stronger underbody construction for the "B" vehicles, it was possible to attach the frame relatively

closer to the underbody than for Vehicle "A". Once the frame was installed

in the test machine, the ends of the I-beam frame members in contact

with the machine platen or the tie-down floor system were secured

by clamping them to tie down points.

3
In addition, hydraulic jacks were placed under the axle hubs of the

vehicle to prevent excessive canting of the vehicle as the side load was applied. Cables were used to restrain the vertical members of

the support frame from excessive deflection during the test. A photograph

showing Vehicle "A" mounted in the test frame and positioned in the

testing machine for a static test is given in Figure 3.

5. TEST VEHICLE PREPARATION

" General characteristics of the vehicles in the test program are listed in Table 1. In preparation for the static and dynamic tests,

a number of non-load bearing parts of the vehicles were removed to

reduce the handling weight, for safety, and for convenience in instrumenting the vehicle. The vehicles were first weighed on a precision mechanical

scale. After weighing, the engine, transmission, fuel tank, side window

glass and sealed beam lights were removed.

Interior trim items removed included the handles, the trim panels

and window mechanisms for the front and rear doors, and the head rests

and safety belt hardware attached to the floor. Components removed

from the roof were the sun visors, shoulder harness assemblies, the

headlining and headlining support rods. Although the rear window was removed from Vehicle "A", which was tested initially, the window was

left in Vehicle "B-1" since the rear window frame carried some shearing

loads during the first tests.

Strain gage locations were selected on the pillars, roof and

sill, and door side guard beams. At these locations, the existing

paint was removed in order to attach the gages to the parent metal

surface. These locations were masked and the surrounding metal and

the doors were painted with several shades of flat grey paint to improve the contrast and to reduce glare from lights when photographing

the various components.

6. STATIC TEST PROCEDURES

6.1 Alignment of Simulated Bumper

The surface area over which crush loads were applied to a vehicle

side with the simulated bumper was established from the following

considerations: a) the determination of a reference point on the side

structure and b) alignment of the bumper with respect to that reference.

The position used for the reference was the Seating Reference Point,

referred to hereafter as SRP, which corresponds to the driver's hip

pivot point. This location, given with respect to the front seat belt

anchorage locations, was obtained for each vehicle through the assistance

of the Automotive Manufacturer's Association. After locating the SRP,

it was marked by use of a circular target glued to the exterior surface

of the front door.

4
Alignment of the bumper relative to the SRP was chosen to achieve

a deformed side structure profile which would be representative of

the profiles generated in perpendicular side impact collisions [2j.

In selecting the bumper alignment, it is useful to measure the re- lative position of the front and side structure of two vehicles having

the same design and weight, such as shown in Figure 4. After considering

these factors, it was decided to align the axis through the center

of the top edge of the steel band incorporated on the bumper face

with the horizontal axis through the SRP, and aligning the center

of the bumper with the vertical axis through the SRP location. This

alignment was checked by use of plumb bobs which were suspended from

the bumper after it was connected to the sensitive crosshead of the

testing machine and the vehicle and test frame were moved onto the

machine platen. After alignment of the vehicle relative to the bumper

was completed, the test frame was rigidly connected to the tie down

points available in the platen.

6.2 Static Test Instrumentation

The responses of the test vehicles to the static crush loads were determined by measurement of deformation and strain at selected

locations on the structural components. Two types of transducers were

used to measure deformation during the static tests: linear variable

differential transformers (LVDT's) and potentiometer transducers

consisting of a flexible steel cable wound on a precision reel coupled

to a potentiometer having a nonlinearity of less than one percent.

A photograph showing an LVDT and three cable transducers is shown

in Figure 5.

The direct current LVDT sensors were calibrated using a calibrating

stand with a micrometer. The maximum nonlinearity of these devices was 0.5 percent of full scale. Their resolution is limited only by

the read-out equipment which is employed. The displacement range for

these transducers was 1 to 2 inches (2.54 to 5.08 cm). For the larger

range potentiometer transducers, a different calibration procedure

was required. It was noted that several of the hydraulic testing machines

in the laboratory had pacing dials which can be used for conducting

mechanical tests at constant crosshead speeds. These dials were graduated

and had a range of approximately 10 inches (25.4 cm). To calibrate

a potentiometer transducer, the transducer was connected between

the fixed and moving crossheads of a testing machine and the cable

motion was controlled by operating the machine using the pacing dial

for a displacement reference. The pacing dial readings were checked

with a dial gage and were repeatable within .006 in (.15 mm) over

the range checked. Since the potentiometer transducers had a range

of up to 2 feet (0.61 m), it was required that their calibration be

performed over several shorter ranges. The resolution of these transducers

5
was less than 0,5 percent of full scale. The errors of the displacement

transducers were well within the SAE recommended practice guidelines.*

The strain gages employed were 120 ohm foil gages with encapsulated

grids having a length of 0,25 inch (0.63 cm). They were attached in

a single arm configuration at various positions and directions on

the vehicle door structure back-up members, such as the pillars, sill

and roof, and on the door side guard beams, dash and front glass.

6.3 Measurement Procedure

The displacement transducers were connected to the structural

members by several different methods. Whenever possible, a small hole was drilled into the sheet metal and a self-locking screw was used

to attach a fixture for supporting the end of the transducer cable.

Where this procedure could weaken a member or otherwise interfere

with the measurement, an adhesive was used to attach the fixtures.

The displacement transducers were connected to signal conditioning

and their output was digitized and recorded on a multichannel data

acquisition system. The strain gages were connected to form a bridge

circuit using signal conditioning within the data acquisition system

and their output was similarly recorded. Other quantities recorded

were a signal from a potentiometer in the testing machine console,

whose output was directly proportional to the load indicator dial,

and the power supply voltage for the transducer signal conditioning.

The static crush tests were conducted using the testing machine

hydraulic controls to load the vehicle side with the simulated buix^ser

which was attached to the machine sensitive crosshead. Load, displacement and strain data were recorded during the test on both paper and

magnetic tape at load increments of several thousand pounds. The short

range displacement transducers were reset whenever necessary, while

the load was held constant, to ensure that their range was not exceeded.

The data printed out on paper tape were spot checked during the test

and visual observations were also recorded on this tape. The magnetic

tape was processed after the test by a high speed digital computer

in order to list the data in tabular form for convenience when performing a more thorough data reduction.

7. DYNAMIC TEST PROCEDURES

7.1 Modification of Bumper

In order to simulate the loading of an intermediate size 4 door

sedan for the drop tests, the weight of the simulated bumper was increased

*e.g., Society of Automotive Engineers Recommended Practices

SAE J211a and SAE J367.

6
to about 4100 lb (1860 kg) by the addition of lead. A steel block

was first welded to the rear surface of the bumper face plate to provide

for the mounting of several accel erometers . In order to keep this

surface intact as molten lead was added, a tubular member surrounding

the accelerometer mounting block was welded in place. Sheet metal

containers were fabricated and attached to the bumper by brackets

welded to the tubular members of the bumper, and molten lead was then

poured into the containers. A photograph of the modified bumper after

solidification of the lead is shown in Figure 6,

7.2 Instrumentation for Dynamic Tests

For computing the load applied by the simulated bumper for the

drop tests, two types of accel erometers were attached to the steel

block welded behind the face plate of the bumper. The primary transducer was a linear piezoresi st i ve accelerometer designed specifically for

automotive crash test applications and having a sensitivity of about

20 mil 1 i vol t s/g . Its full bridge design featured semiconductor elements

connected in one side of a bridge and fixed precision resistors for

internal bridge completion and shunt calibration. The low resistance

of the piezoresistive transducers minimize electrostatic problems

due to cable motion which have been encountered with higher resistance

accel erometers whenever long cable lengths are required. The cableaccel erometer interface used recessed solder terminals. In order to

further minimize any effects of cable motion, the terminal recess was filled with a sil icone-rubber compound and the transducer cable

was taped to the bumper at several locations near the transducer.

The secondary transducer was a piezoelectric transducer, having

built-in signal conditioning, with a sensitivity of about 19 mil 1 ivol ts/g.

This transducer was rugged but did not respond as well as the piezoresistive accelerometer at low frequencies. The battery supply required

for this device was rigidly connected to the simulated bumper.

Prior to instrumenting the test vehicles, several experiments

were conducted to determine the capability of the potentiometer transducers to survive and respond rapidly when subjected to the high speed

displacements generated during the impact test. It was determined

that neither the commercial nor the NBS developed transducers could

respond fast enough unless the cables were extended, rather than being

retracted as during the static tests. Since the NBS developed transducers

of the type shown in Figure 5 were more rugged than the commercial

devices, they were chosen for this purpose. It was necessary to employ

a 110 Ibf (489 N) capacity 7 strand cable and to modify the cable

connection to ensure that the cable would withstand the loads developed

when it was suddenly extracted from the transducer at speeds up to

15 miles per hour (6.71 m/sec).

Two high-speed motion picture cameras were used for photographic

coverage of the drop tests. The maximum camera speed was 4000 frames

per second and high speed movie film was used to reduce the amount

7
of auxiliary lighting required. A time base for the film was provided

by a lamp enclosed in the camera housing which produced marks along

one edge of the developed film outside the picture area. The frequency

of the light was controlled so that an interval of 0.00833 seconds

occurred between successive flashes.

The basic recording instrumentation consisted of two types of

transient waveform recorders which convert analog signals to digital

form, store the signal data in a memory and reproduce the original

signal when desired. The recorded output is a reconstructed analog

facsimile to the input. The memory can be operated so as to freeze

its contents, recirculate them and make them available for repetitive

readout on an oscilloscope or a chart recorder. Two of the recorders

used had two 1024 word memories and one of the recorders had four

1024 word memories which could be operated as a single channel 4096

word memory recorder. Since there was some uncertainty in selecting

the sample rate for recording the signals, the procedure used was

to record the acceleration and displacement data on several recorders,

using different time base selections. A block diagram of the recording

instrumentation is shown in Figure 7.

7.3 Measurement Procedure

The simulated bumper was positioned for the drop tests by attaching

it to the monorails of the lower hoist on the 1 2-mi 1 1 ion-lbf capacity

universal testing machine, shown in Figure 2. First a 6 foot (1.83

m) long spreader bar was bolted to the ends of the monorails which

extended about 14 feet (4.27 m) from the center of the working space

on one side of the testing machine. A solenoid operated quick release

having a rated capacity of 4,500 Ibf (20.0 kll) was then bolted to

the spreader bar. A 2 foot (0.61 m) long spreader bar was bolted to

the top of the bumper support structure and the bumper was then attached to the quick release with a shackle bolted to the latter bar.

Steel cables were connected from the top of the bumper to the monorails.

The cables had enough slack to permit the bumper to fall freely over

the desired length and to intrude into the vehicle side, but they

constrained the bumper from excessive rotation and from falling to

the floor after impacting the vehicle. The elevation of the bumper was controlled by moving the machine sensitive crosshead to which

the monorails were attached.

The test vehicle was attached to the support frame in the same manner as for the static tests, and the vehicle-frame assembly was moved into position below the elevated bumper. Prior to anchoring

the support frame to the testing machine tie-down floor system, the

vehicle was aligned with respect to the bumper using plumb bobs suspended

from the bumper in the same manner as for the static test setup. After

the support frame was attached to the tie-down floor, arrangements

were made for triggering the recording instruments and providing a displacement reference marker for determining the bumper position

when analyzing the high-speed movies after completion of the test.
The dynamic test setup, reconstructed after one of the tests, is shown

in Figure 8.

The recording instruments were triggered by a microswitch equipped

with a nylon cord strung above the test vehicle side structure. As

the bumper fell, it deflected the cord so that the microswitch would

be activated when the bumper was about 1 inch (2.54 cm) above the

vehicle door surface. The signal lead from the microswitch was attached

to a triggering circuit which generated a 14 dc-volt decaying pulse

of about 12 microseconds duration when the switch was closed. This

signal was fed to the triggering inputs of each of the recorders which

were adjusted to be activated simultaneously.

A displacement reference marker was provided by attaching alternate light and dark pieces of tape to a channel member which ex- tended through the window opening of the front door of the test vehicle.

Sections of this tape were also attached to several of the bumper

support tubular members to assist in determining the bumper position

when the high-speed movies were analyzed.

Several preliminary drop tests were made on one side of Vehicle

"A", which had been tested earlier, in order to determine the proper

time base settings for the waveform recorders. Since there was some uncertainty in choosing the time base, the recorders were adjusted

for different durations, varying from 20 to 100 milliseconds. The

drop heights used for the preliminary tests were about 1 to 2 feet

(0.30 to 0.61 m). Vehicle "A" was then removed from the machine and

Vehicle "C-1", an untested vehicle, was installed. This vehicle was

similar in design and construction as Vehicle "B-1" but was in better

condition. The drop height for Vehicle "C-1" was based on the energy

absorbed by Vehicle "B-1" during one of the static crush tests. This

energy value was computed from the measured force versus defonnation

data on the door structure. In order to produce the same amount of

kinetic energy during the drop test as the energy absorbed for the

static test, it was necessary to drop the bumper 7,5 feet (2.29 m)

so its impact speed would be 15 miles per hour (6.71 m/sec).

Two high-speed movie cameras were focused so that they would

record the striker motion just prior to its impact with the vehicle

side structure and the entire bumper motion during subsequent crushing

of the structure. An adjustable transformer was employed to reduce

the line voltage to obtain a camera speed of about 2000 frames per

second. A color movie camera having a speed of about 24 frames per

second was used to record the entire drop test. The cameras were started

just prior to activating the quick release which dropped the bumper.

9
8. ANALYSIS OF DATA

8.1 Static Crush Tests

8.1.L Strain Measurements

Some useful information was obtained from examination of the

strain data taken during the static crush tests of Vehicles "A" and

"B-1". A summary of those locations in which the largest strains were measured is shown schematically in Figures 9a, 9b and 9c." The largest

strains, indicated by the open circles, were measured along the sill

and on the sheet metal supporting the front door hinges for each of

these vehicles. Large strains measured on the portion of the B pillar

above the window opening on the right side of Vehicle "A" and the

left side of Vehicle "B-1" were^ in a local buckling region of the

pillar. The location of this region, which was 2 to 3 inches (5,1

to 7.6 cm) above the lower edge of the window opening, was not known

when the left side of Vehicle "A" was loaded. Additional locations

where large strains were measured on Vehicle "B-1" are attributed

to one or more of the following: 1) the larger magnitude of the applied

load, 2) the difference in construction of the frame members for Vehicles

"A" and "B-1" and 3) the effect of the door side guard beam which

was not present in the door structure of Vehicle "A".

Additional observations may be made from analysis of strain data

presented in a graph of load versus strain for a particular location

or for adjacent locations on the side structure. An example of the

former is shown in Figure 10, which gives the load versus strain measured in the X direction on the sheet metal supporting the upper front

door hinge of Vehicle "A" during the crush test of its left side.

Even though variations exist in the strain with increasing load, an envelope for this data encompassing the extreme points would be re- latively narrow and uniform. This observation suggests that the loading

at this position was essentially continuous throughout the test, a suggestion further supported by examination of displacements measured

in this region, the data for which will be discussed later. An examination of the load versus deflection measured in this region was made

for purposes of a graphical estimation of the load required for buckling of the sheet metal; however, the deflection data were not sufficiently uniform to permit this to be achieved.**

"'The convention for the coordinate system and the vehicle pillars

used in discussion of the measurements is also shown in these figures.

*'''This may be accomplished if experimental data which tend toward

limiting values are sufficiently hyperbolic in character [6j.

10
An example where strain data obtained from gages at adjacent

locations may be used to gain insight concerning the sequence of loading of various components is shown in Figure 11, where strains measured at the front and rear door side guard beams of Vehicle "B-1"

are compared with the strain at the B pillar in line with the top

edge of the door beams. It is observed from this plot that the strain

in the side guard beam follows the same trend as that measured on

the B pillar up to a crush load of 16,000 Ibf (71.2 kN). Thereafter,

the strain developed in the B pillar decreases (probably due to the

local buckling previously noted), while that in the side guard beam

continues to increase.

Relatively little can be concluded from comparison of the strains

measured in different directions since the data represent only the

localized strain conditions, which may be quite discontinuous. It

should be noted, however, that large strains were measured in all

directions on the sheet metal adjacent to the front door hinges and

along the sill. This result is in apparent agreement with a conclusion

by Dale, et al , that the supporting sheet metal structure of latches

and hinges usually fails before the latches or hinges [7j.

The principal usefulness for strain measurements in this investigation was to obtain qualitative and comparative information about

vehicle side structure crush characteristics. Useful insights can also be gained regarding the load transmission during a static crush

test, as shown by the above examples, to supplement interpretation

of measured displacements during these tests.

8.1,2 Analysis of Static Displacements

The positions on the side structure at which displacements were measured for the vehicles were the front and rear doors, the A and

B pillars and the displacement between the pillars. In addition, displacements were measured at a door side guard beam and the front seat

for Vehicle "B-1", and the firewall for both vehicles. The front seat

and firewall, although internal structural members, may be considered

as part of the side structure in the sense that they sustain loads

during crushing of the vehicle side. For convenience in distinguishing

between various structural degrees of freedom for the vehicle components,

the test results are analyzed in terms of the following modes of deformation 1) doors, side guard beam and B pillar lateral deformation, 2)

A and C pillars and additional modes of B pillar deformation, 3)

deformation of internal structural members, and 4) local failure of

structural members, joints and connections.

8.1,2.1 Doors, Side Guard Beam and B Pillar Lateral Deformation

The doors and B pillar are considered together because it was observed that they tended to deform as a unit in resisting lateral

intrusion, especially in the early portion of the static crush tests.

The displacement of the B pillar was measured at two positions located

11
at the same elevation (Y direction), one being Located forward and

the other rearward of the center of the pillar. This was done to discriminate between the translational intrusion deformation (parallel

to the Z axis) and rotational deformation of the pillar (in the XZ plane) which is described in the following section. The load versus intrusion deformation measured at several locations during crush

tests of the Vehicle "A" left and right sides and the Vehicle "B-1"

left side are shown in Figures 12, 13, and 14, respectively. The location

of the displacement transducers on the doors and B pillar for Vehicle

"A" was about 14 inches (35.6 cm) above the rear floorpan. The corresponding

position on Vehicle "B-1" was about 17 inches (43.2 cm) above the

door base and the displacement transducer attached to the rear door

side guard beam was about 14 inches (35.6 cm) above the base of the

door near the center of the beam. The vertical positions of all these

transducers were approximately in line with the center of the simulated

bumper. An example of the structural response of a component over

the entire loading and unloading cycle is shown in Figure 15, for

a side guard beam of Vehicle "B-1"."

One general observation from the measured intrusions is that

the B pillar deformation was always less than that measured at the

doors. This result is to be expected since the door outer panels,

to which the end of the transducers were attached inside the doors,

began to deform before significant loads developed through the front

door latch and rear door hinges to the B pillar. Another observation

is that the deformation measured at the front door was generally larger

than at the rear door.** At the conclusion of the test, the edge of

the front door adjacent to the B pillar was observed to have intruded

further than the corresponding edge of the rear door. The portion

of the rear door nearest the latch appeared to have rotated about

the latch as the door was crushed, probably due to the striker cur- vature in this region. A plot of the maximum intrusion profile for

the right side structure of Vehicle "A" is shown in Figure 16,

Lateral deformation of the B pillar was determined by taking

an average of the deformations measured at two points at the same elevation spaced about L2 inches (30.5 cm) apart. The cables of the

transducers were attached to a stiff plate which was bolted to the

B pillar to accomplish this measurement. By examination of the data

obtained from each transducer, the load range over which the B pillar

exhibited uniform lateral deformation could be determined. For Vehicle

"A", this region extended to a crush load of about 11,000 Ibf (48,9

kN), beyond which the deformation became more complex. Thus the data

*The elastic recovery observed from analysis of the data at this

location was about 0,8 inch (2,03 cm).

**This result was achieved only during the static crush tests,

during which the simulated bumper was constrained to move in one direc'

tion.

12
for the B pillar deformation plotted in Figures 12 and 13 were limited

to this range. For Vehicle "B-1", the lateral deformation of the B

pillar tended to be more uniform over the entire load range.

It should be noted that there were differences in both the design

and the deformation modes for the B pillars of Vehicles "A" and "BI" which could influence the pillar response. The sheet metal thickness

for the B pillars of Vehicle "A" was 0.055 inch (1.40 mm), whereas

the corresponding thickness for Vehicle "B-1" was 0.080 inch (2.03

mm). In addition, the distance between the B pillar and the front

seat for Vehicle "A" was about 3 inches (7.62 cm), whereas the cor- responding distance for Vehicle "B-1" was about. 3.5 inches (8.89 cm).

It is not known precisely when the B pillars first came into solid

contact with the front seat, but based on visual observations made

during the test this occurred at a load of about 12,000 Ibf (53.4

kN) for Vehicle "A" and at about 23 ,000 Ibf (102.3 kN ) for Vehicle

"B-1". Plots of the maximum intrusion profile of the B pillar for

Vehicles "A" and "B-1" are shown schematically in Figures 17 and 18,

respectively.

8.1.2,2 Deformation of A and C Pillars and Additional B Pillar Modes

Plots of the deformation measured at the A pillar versus load

for the Vehicle "A" right side and Vehicle "B-l" left side are shown

in Figure 19. The end of the transducer cable was located near the

lower hinge, about 6.5 inches (16.5 cm) above the floorboard, for

Vehicle "A" and midway between the hinges, about 12 inches (30.5 cm)

above the floorboard, for Vehicle "B-1". It is observed that the deformation increased uniformly with load at this location. Visual ex- amination of the sheet metal around the front door hinges indicated

that the A pillars experienced significant rotational, as well as translat ional , deformation. This result is attributed to the design

of the simulated bumper whose curved front surface would tend to induce rotation of the A pillar against which the curved portion was bearing.

Another mode of deformation is Indicated by a measurement of

the change in the distance between the A and B pillars during the

crush test of the Vehicle "A" left side, plotted in Figure 20. The

displacement transducer used for this measurement was located in a horizontal position (parallel to the X axis) about 12 inches (30.5

cm) above the floorboard. Similar measurements were made of the change

in the distance between the B and C pillars for the right side of

Vehicle "A" and the left side of Vehicle "B-1", as shown in Figures

21 and 22, respectively. For Vehicle "A", the distance between the

B and C pillars first increased and then decreased up to a load of

about 18,000 Ibf (80.1 kN). Beyond this load, the distance between

the pillars increased continuously for the remainder of the test.

For Vehicle "B-1", the distance between the B and C pillars decreased

a small amount up to a load of about 4,000 Ibf (17.8 kN). Thereafter,

the distance between the pillars increased continuously until a load

13
of about 24,000 Lbf (106. 7 kN), after which the range of the transducer

was exceeded. At the conclusion of the test of Vehicle "B-1" it was found that the A and C pillars were about 0.5 inch (1.27 cm) closer

together than their original separation.

No measurements were made of the C pillar deformation other than

its deflection relative to the B pillar. Strain data recorded at several

locations on the sheet metal adjacent to the rear door latch indicated

that significant strains never developed in this region. There was

no visible deformation of the C pillar during the test on the Vehicle

"A" left side. For the test on the Vehicle "A" right side, there was

a region of local buckling near the roof structure and at the rear window opening in the vicinity of the C pillar. After the test on Vehicle "B-1", the only observed deflection of the C pillar was some small deformation of the sheet metal near the top of the rear seat.

A vertical profile showing the relative permanent deformation of the

three pillars after the crush test of Vehicle "B-1" is shown schematically

in Figure 23.

The angular deformation of the B pillar (in the X-Z plane), which

was derived from analysis of the two displacement measurements previously

noted, for the right side of Vehicle "A" and the left side of Vehicle

"B-1", is plotted in Figure 24. This deformation was determined by

taking the difference in the displacements measured at two locations

on a stiff plate bolted to the pillar for each recorded load, dividing

this difference by the distance between the transducer positions and

converting the resulting value to an angle. This deformation was determined

by taking the difference in the displacements measured at two locations

on the pillar for each recorded load, dividing by the distance between

the transducer positions and converting to an angle.

In summary, the measured deflections show that significant deformations of the B pillar for Vehicles "A" and "B-1" include lateral displacement (parallel to Z axis), longitudinal displacement (parallel to

X axis), angular displacement (in the X-Z plane) or some complex combination of these responses at various loads throughout the tests. A relatively

small number of positions were selected for the measurements of each

of the principal structural components in order to include as many

components as possible. The local buckling, yielding and fracturing

of components observed after the tests, which will be reviewed later,

provided additional insight for a more complete evaluation of member

performance during the static crush tests.

8.1.2.3 Deformation of Internal Structural Members

The deformation of the firewall was measured at one location,

parallel to the X direction, during the crush tests for the Vehicle

"A" right side and Vehicle "B-1" left side. This data is shown plotted

in Figure 25. The firewall surface contour of both vehicles was quite

nonuniform and the deformed profile after the tests was complex. In

order to highlight the topography of the deformed firewall surface,

a 2 inch (5.08 cm) square grid was painted on the firewall before

14
the test for Vehicle "B-1". Photographs taken before and after the

crush tests are shown in Figure 26. For complex components such as the firewall, such a grid can be used to supplement deflection measurements

and to indicate appropriate positions for the transducers if additional

displacement measurements on similar vehicles are desired.

Since it was expected that the front seat of the vehicles would

afford some resistance to intrusion into the occupant compartment,

an attempt was made to measure the deformation of the seat at one

location. During the crush test of the Vehicle "B-1" left side, the

end of a cable transducer was attached to the structural member at

the top of the front seat at its midspan. The recorded deformations

in the longitudinal (X ) direction versus the crush load are plotted

in Figure 27. This result shows that the seat exhibited considerable

deformation at loads above 23,000 Ibf (102,3 kN). The maximum deformation at the midspan of the seat exceeded the range of the transducer

after a load of about 28,000 Ibf (124,5 kN), A useful method for determining

the effectiveness of a front seat in resisting a side crush load would

be to crush two identical vehicles, one having the seat and the other

without, and compare the load versus deflection of the side structural

members for the two tests.

8.1,2.4 Local Failure Modes of Structural Members,

Joints and Connections

The modes of failure for components other than those established

from the measured deflections and for structural connections included

local buckling, yielding in a localized plastic zone or combinations

of buckling and plastic yielding, and fracture.

During the crush test of the Vehicle "A" left side, the first

observed regions of local deformation other than the doors were on

the sill adjacent to the B pillar and at the junction of the forward

end of the sill with the vehicle front quarter panel. These regions,

which are shown encircled in Figure 28, appear to indicate that the

initial small crush loads were transferred through the doors and A

and B pillars to the sill." Other regions encircled on the B pillar

in this photograph reveal an angular deformation at the surface of

the sheet metal supporting the rear door lower hinge and a complex

region of local buckling and yielding on the B pillar several inches

above the door window sill. After the test, it was observed that the

sheet metal between several of the spot welds in this region of the

pillar had buckled and the sheet metal had torn away from one of the

welds.

"The doors were removed from the vehicle for this photograph in

order to highlight the deformation of the pillars and sill.

15
As can be observed from Figure 28, the central portion of the

B pillar appears to have been displaced uniformly toward the occupant

compartment, which is further indicated by the small strains recorded

in this region. The above noted zone of yielding occurred in the upper

portion of the pillar just above where the reduced cross section of

the pillar began. A similar failure mode occurred during the test

of the Vehicle "A" right side in the same region, but less buckling

developed in the sheet metal between adjacent spot welds. This localized deformation was probably related to the previously described

changes in displacement measured between the pillars.

During the crush test of the Vehicle "A" right side, a maximum

load of 20,000 Ibf (89.0 kN) was applied. After the test it was observed that the spot welds at the base of the B pillar had fractured,

A photograph showing this region on the inboard side of the pillar

is given in Figure 29. Sheet metal fractures were also observed at

several spot welds which joined the outer surface of the B pillar

to the sill, and at two diagonal corners of the rear window opening.

Considerable buckling occurred across the dash during the test

of the Vehicle "A" right side, as shown in Figure 30. Since no significant

deformation of the dash was observed for loads up to 15,000 Ibf (66.7

kN), the dash buckling developed somewhere between this load and the

maximum applied load of 20,000 Ibf (89.0 kN). The deformation which

initially occurred in the middle of the dash precipitated a fracture

at the base of the windshield adjacent to the dash, and the large

deformations which occurred later caused fracture of the front glass

adjacent to the A pillar.

During the crush test of the Vehicle "B-1" left side, a major

fracture developed in the B pillar where the pillar cross section

changed shape just above the door window sill. The deformed profile

of the B pillar at the conclusion of this test, shown schematically

in Figure 18, suggests that a zone of plastic yielding could have

formed in this region which led to the fracture of the pillar.

The displacement of the B pillar near the roof was measured during

the test of the Vehicle "A" right side. Its deformation with respect

to the B pillar on the left side of the vehicle is shown in Figure

31, for a portion of the load range. The strains at the intersection

of the B pillar and roof structure were generally small and no fractures occurred in this region except at the larger crush loads during

the last portion of the test of Vehicle "B-1". There was some local

yielding and separation occurred between the roof cross beam and the

roof sheet metal near the B pillar for each of the tests. This deformation was apparently related to the local buckling of the roof

sheet metal adjacent to the pillar which was observed during the tests.

The crush test on the left side of Vehicle "B-1" was more severe

than the tests of Vehicle "A". Sheet metal fractures were generated

in the sill near the B pillar, at the base of the A and B pillars

16
and at the top of the A pillar near the roof, and there was local

buckling along the top edge of the front window frame during the test

of Vehicle "B-1". The strain which was determined at one location

on the front glass was insignificant. No fractures developed anywhere

on the front glass during the test until loads of 20,000 Ibf (89.0

kN) or larger were applied, after which a fracture developed near

the A pillar and the front glass began to separate from its molding

around the top and sides of the window opening. Fractures which developed in the sheet metal at several corners of the rear window opening

of Vehicle "A", whose rear window had been removed, were not observed

during the test of Vehicle "B-1" whose rear window was left installed.

As a final example of a localized failure mode, the deformation

of the side guard beam for the rear door of Vehicle "B-1" is considered.

Examination of Figure 15 indicates that the response of the side guard

beam could be approximated by a series of several successive increments

over which the measured load versus deformation is approximately linear.

The nature of this response resembles that of a built-in beam, loaded

by a concentrated force, which experiences several piecewise linear

load versus deflection increments due to the formation of plastic

hinges before final collapse [8, 9j. An examination of the deformed

rear door after the test of Vehicle "B-1" indicates that it did ex- perience a load which was distributed over a small area near its midspan

due to the relative position of the door with respect to the curved

portion of the simulated bumper. Figure 32 shows the deformation of

the rear side guard beam which was photographed after removing the

outer panel of the rear door. A more detailed investigation would

be required in order to determine whether the failure of the side

guard beams in fact develops due to successive formation of plastic

hinges.

8,2 Dynamic Crush Tests

For the drop test on Vehicle "C-1", the simulated bumper intruded

into the vehicle side structure about 13 inches (33.0 cm) and then

rebounded several inches before rotating and sliding away from the

door toward the roof structure. Subsequent analysis of the high-speed

movies indicated that the top edge of the bumper moved about 19 inches

(48.3 cm) with respect to the displacement reference marker, the last

6 inches (15.2 cm) of which was associated with rotational motion

and sliding of the bumper. One of the two constraining cables broke

after the bumper began rotating in the direction of the roof structure,

after which the bumper impacted the front of the roof and the hood

before coming to rest. The movies indicated that some local buckling

of the roof structure had occurred prior to breaking of the cable.

A plot of the bumper displacement with respect to the fixed reference

marker versus time is shown in Figure 33. The maximum deceleration

17
recorded at the center of the bumper was about 7 g."

Vehicle "C-L" was removed from the testing machine and Vehicle

"B-2", which was identical to Vehicle "B-1", was installed. The vehicle

was oriented so that the falling bumper would strike it in the same position as during the static test on Vehicle "B-1". The drop test was conducted in the same manner as for Vehicle "C-l" with the same drop height. For this test, modifications were made to strengthen

the cable and to reduce the effect of the sharp edges of the testing

machine monorails which were believed to contribute to breaking the

cable during the previous test. These modifications proved successful

in constraining the bumper after its maximum intrusion into the vehicle

side structure.

The bumper displacement with respect to the fixed reference marker

versus time was determined from analysis of a high-speed movie, and was found to correspond closely to similar data obtained from the

test on Vehicle "C-l" for displacements up to 16 inches (40.6 cm).

The values of displacement versus time obtained from the movies by

two observers generally agreed within about 5 percent. The maximum

deceleration recorded at the center of the bumper was about 6 g.

The output signals from the displacement transducers attached

to the front and rear door side guard beams were oscillatory in form

and were not well defined. It is believed that stress waves in the

transducer cable or in the member connecting the transducer to the

door beam were recorded. The structural components generally deform

in several directions during vehicle crushing, as the static test

data indicated, further complicating analysis of the signals.

In order to determine the deformation of the door structure at

various time intervals during the impact, polynomial equations of

various orders were fitted through the data points obtained from analysis

of the movie film. It was found that several polynonial equations

gave essentially the same curve which passed through the experimental

data. An attempt to differentiate these equations to obtain acceleration

versus time information from the measured displacement versus time

data proved unsuccessful, since several distinct solutions seemed

to be plausible. The displacement versus time information was useful,

however, in correlating the bumper acceleration and deformation of

the front door panel at different time intervals. The bumper accelerations were converted to force, using the known niass of the bumper.

The resulting transient load versus deformation data for the dynamic

tests is compared with the static test results in the following section.

"Acceleration values are frequently given in terms of "g", the

acceleration due to gravity (9,80665 m/s ),

18
9. COMPARISON OF STATIC AND DYNAMIC TEST RESULTS

Several methods can be employed to compare the static and dynamic

crush test results. Figure 34 shows the overall damage incurred in

the side door structure during the static test of Vehicle "B-1" and

the dynamic test of Vehicle "B-2", A plot of the exterior deformation

of the vehicle left side after the two tests is shown in Figure 35.

An examination of the permanently deformed rear door side guard beam

after the drop test for Vehicle "B-2" is shown in Figure 36, which

can be compared with the corresponding damage produced during the

static crush test of Vehicle "B-1" which was shown in Figure 32.

In order to compare the transient load applied to the Vehicle

"B-2" door structure during the dynamic crush test with the static

load applied to the side of Vehicle "B-1", the deformation

of the front door panel at various time intervals was first obtained

from the movies taken during the drop test. The values of door panel

deformation were then plotted with respect to the transient load

obtained from analysis of the acceleration signals measured at the

center of the bumper at corresponding increments of time, starting

when the door was first deformed. This data is presented in Table

2 and is also plotted in Figure 37. The acceleration data used to

compute the dynamic load represents the maximum single amplitude of

the basic signal which was recorded, ignoring both low frequency electrical

noise and high frequency spurious noise components.

The ratio of the static to dynamic loads at corresponding values

of the door panel deformation can be interpreted as dynamic empirical

factors for comparing the static and dynamic crush characteristics

of the door structure. It should be noted that the sudden decrease

in the dynamic load value after a door deformation of about 5.4 inches

(13.7 cm) is probably due to some change in the distributed load across

the face of the simulated bumper. Examination of the deformed side

doors following either static or dynamic crush tests has indicated

that toward the end of the test, the largest forces tend to be aplied away from the bumper center and near the curved portions of its

face

The applied loads for the two tests were compared for only a limited range of door panel deformation. As shown in the series of

movie frames of the drop test immediately after the bumper impacted

the side of Vehicle "B-2", there is a tendency for the bumper to rotate

toward the rear door initially and afterwards to rotate in another

plane, toward the roof structure. Thus, one interpretation for the

sudden decrease in the acceleration measured at the center of the

bumper is that it may represent the onset of rotational motion of

the bumper after its linear motion has essentially terminated. The

load factors in Table 2 obviously are most meaningful when the motion

of the bumper is principally in one direction, as during the static

tests.

19
Comparison of the damaged Vehicle "B-2" after the drop test re- vealed that its B pillar had experienced local plastic yielding near

its midpoint at the lower level of the door window opening. In addition,

the B pillar had been crushed against the front seat as the B pillar

had been during the static crush test of Vehicle "B-1". The lesser

amount of damage done to the seat and the dash of Vehicle "B-2" for

the drop test than during the corresponding static test of Vehicle

"B-1" is believed to be due to the smaller range of linear striker

motion during the drop test than for the static test. Measurements

taken before and after the drop test indicated that the permanent

deformation of the front and rear door side guard beams for Vehicle

"B-2" was about 6.45 inches (16.4 cm) and 7.50 inches (19.0 cm), respectively.

From an examination of the permanently deformed door structures

of Vehicles "B-1" and "B-2", together with the quantitative data presented, it is apparent that the motion of the simulated bumper was significantly constrained during the static crush test. As a consequence

of this constrained motion, the forces were applied more uniformly

to the front and rear door structures than during the dynamic crush

tests as shown by comparison of the deformed structures in Figure

35. In addition, the bumper continued crushing Vehicle "B-1" until

the indicated static load had begun to decrease.* The large deformations

which occurred in the front seat, dash and firewall during the static

crush test were the consequence of the constrained bumper motion.

During the drop tests, the bumper linear motion was evidently transformed

into rotational motion toward the rear door structure after sufficiently

large reactions developed at the forvard end of the bumper by the

front door and its adjacent frame members. After this motion had developed

and the maximum intrusion of the bumper into the door structure had

occurred, the remaining inertial forces were expended in the rotation

of the bumper toward the roof structure.

10. CONCLUSIONS AND RECOMMENDATIONS

Laboratory test procedures wore developed for evaluating the

crush characteristics of automotive structural components which perform a major structural function in side impacts. Strain measurements

taken during the static tests were useful in determining regions on

the back-up pillar and frame members for the door structure where

significant strains developed. The load versus deformation relationships

of various structural components and the deformations measured between

some of the components are a useful method for describing the crush

characteristics of vehicle members. Visual examination of permanently

"In order to establish guidelines for the maximum static loads

to apply to a vehicle, static and dynamic crush tests would have to

be conducted and their results correlated for additional vehicles.

20
deforroed members together with some of the measured displacements

can be used to determine regions of localized plastic deformation

and the significant structural degrees of freedom. The techniques

which were developed could be used to determine the crush characteristics

of additional structural members and to determine modes of deformation

other than those examined in this program. In addition, significant

information about the crush characteristics of structural components

when loaded at different angles could be obtained with minor modifications

to the procedures employed in this program.

The determination of the deformation of vehicle components at

loading rates experienced during typical impact speeds requires further

development to supplement such generally employed methods as highspeed photography. Techniques for direct measurement of component

deformations in several directions at .arious loading rates places

severe requirements on both the ruggedness and accuracy of transducers.

In addition, instrumentation costs for dynamic testing tend to become

considerably larger than for static testing when detailed information

is sought for a large number of members. Although the instrumentation

employed for this purpose in this study survived the severe test en- vironment, additional research would be required to minimize wave

effects and to ensure that complex motions can be properly measured.

The test procedure could be readily modified so the motion of the

simulated bumper during the static and dynamic crush tests would more

nearly correspond to one another. Furthermore, the photographic techniques could also be refined so that greater resolution of the bumper

motion during dynamic tests could be obtained from analysis of highspeed movie films.

The results of this program indicate that static crush data can

be very useful in supplementing dynamic laboratory evaluations of

vehicle crush characteristics. The test procedures developed may be

employed in the evaluation of component designs for limiting intrusion

or redistributing loads or to provide techniques for obtaining data

required for computer simulations of vehicles during side impacts.

11. ACKNOWLEDGEMENTS

Useful information was provided by B. Krauss and G. Braimmeier

who were Contract Technical Managers for this project for the National

Highway Traffic Safety Administration. The valuable assistance of

A. F. Kirstein, C. Federman, R. S. Koyanagi and R. A. Mitchell in

various aspects of this program is gratefully acknowledged. The author

is indebted to J. R. Hazzard for design and test assistance, to J.

L. Michalak and R. E. Snyder for instrumentation, to N. Halsey for

photographic results and to R. W. Peterson for assistance in data

reduction.

21
12. REFERENCES

1. Thompson, J. E., Control of Structural Collapse in Automotive

Side Impact Collisions, PhD Dissertation, University of Detroit,

1972.

2. Galganski, R. A., and Napierski, V. F., Basic Research in Crashworthiness II - Development of Moving Barrier Test Technique,

Calspan Corp. Report No. YB-2937-V-1 3

, Interim Technical Report

to U.S. Dept. of Transportation, National Highway Traffic Safety

Administration, Contract No. FH-11-7622, January 1973.

3. SAE Recommended Practice J972a - Moving Barrier Collision Tests,

SAE Handbook, Part 2, 1974.

4. Kirstein, A. F., Universal Testing Machine of 1 2-Mil 1 ion-lbf Capacity

at the National Bureau of Standards, NBS Special Publication 355,

September, 1971.

5. SAE Recommended Practice J367 -Pas senger Car Door System Crush

Test Procedure, SAE Handbook, Part 2, 1974.

6. Kirstein, A. F., The Hyperbolic Character of Certain Experimental

Results Which Tend Toward Limiting Values, NBS Technical Note

43 5, November 1967.

7. Dale, E, S., et al , Test Procedures and Requirements for Door

System Evaluation, Dayton T. Brown, Inc. Final Report No. DTB22P70-

1540 for DOT National Highway Traffic Safety Administration under

Contract No. DOT-HS-005-1 -005 , March 1971.

8. Plastic Design in Steel, A Guide and Commentary, ASCE Manuals

and Reports on Engineering Practice - No. 41, 1971.

9. Rogers, G. L., Dynamics of Framed Structures, John Wiley and Sons,

Inc., 1959.

22
Table 1 - General Characteristics of the Test Vehicles

Vehicle

Designation Year

Approximate

Mileage

Door Side

Guard Beam

Side

Tested

Type of

Test

"B-1"

"B-2"

"C-1"

1970 82,000

1969 200,000

1969 200,000

1971 90,000

No

No

Yes

Yes

Yes

Left

Right

Static

Static

Left Static

Left Dynamic

Left Dynamic
Table 2 - Comparison of Applied Loads During Static and Dynamic Crush

Tests at Corresponding Values of Side Door Deformation

Ratio of

Front Door Panel Static Dynamic Static to

Deformation Load^ Load^ Dynamic Load

in(cm) lbf(ki>I) Ibf(kN)

1.9 (4.83) 13,100 (58.27) 11,600 (51.60) 1.13

2.8 (7.11) 18,000 (80.06) 17.200 (76.51) 1.05

3.9 (9.91) 22,100 (98.30) 20,900 (92.96) 1.06

5.4 (13.7) 23,800 (105.9) 25,300 (112.5) 0.94

6.5 (16.5) 25,300 (112.5) 17,900 (79.62) 1.41

7.8 (19.8) 27,600 (122.8) 16,400 (72.95) 1.68

9.1 (23.1) 29 , 100 (129.4) 14,500 (64.50) 2.01

Load during static crush test of Vehicle "B-1" left side.

Load during dynamic crush test of Vehicle "B-2" left side (obtained

using acceleration measured at center of simulated bumper and

bumper mass).
Figure 1 - SIMULATED BUMPER USED FOR STATIC CRUSH TESTS
Figure - 2 - UNIVERSAL TESTING MACHINE OF 12,000.000 Ibf CAPACITY
Figure 3 - STATIC TEST SETUP IN UNIVERSAL TESTING MACHINE
Figure 4 - RELATIVE POSITION OF BUMPER AND SIDE STRUCTURE FOR TWO SIMILAR VEHICLES
Figure 5 • DISPLACEMENT TRANSDUCERS USED DURING STATIC CRUSH TESTS
Figure 6 - MODIFIED SIMULATED BUMPER USED FOR DYNAMIC CRUSH TESTS
z ae

OOS QQ

ME »—

«c oe

UJ

CD

C-3 C9

C9

C9

to

I—

CO
Figure 8 - DYNAMIC TEST SETUP (RECONSTRUCTED AFTER DROP TEST)
Figure 9a - SCHEMATIC OF VEHICLE

A LEFT SIDE SHOWING REGIONS OF MAXIMUM RECORDED STRAIN
Figure 9b - SCHEMATIC OF VEHICLE A RIGHT SIDE SHOWING REGIONS OF MAXIMUM RECORDED STRAIN
Y

Figure 9c - SCHEMATIC OF VEHICLE B-1 LEFT SIDE SHOWING REGIONS OF MAXIMUM

RECORDED STRAIN

T"

24,000-

20,000-

16,000-

I2»000-

8,000-

4,000-

-1000

+ O

0

0 +

Of

Of

^ STRAIN ON 6 PILLAR

O STRAIN ON FRONT DOOR

SIDE GUARD BEAM

STRAIN ON REAR DOOR

SIDE GUARD BEAM

1000 2000 3000 4000 5000

STRAIN X 10

Figure 11 - LOAD VERSUSSTRAIN AT SEVERAL LOCATIONS ON SIDE STRUCTURE

DURING STATIC CRUSH TEST OF VEHICLE B1
16,000

14^000-

12,000-

io,oao|-

8,000

6^000-

4,000 -

2,OOo|- O

O

T 1 1 r- 4

+

€0 +

dHO-f

O +

o +

+

+

+

4- FRONT DOOR

REAR DOOR

O B PILLAR

i.O 20 3.0 4.0

INTRUSION DEFORMATION, in

5.0 &0

ure 12 - LOAD VERSUS DEFORMATION AT THREE LOCATIONS ON THE LEFT SIDE

OF VEHICLE A
2 ;,ooo -Of

I 8,000

16.000

I4.J00

Z.OOO

10 300

8.CC0

6.000

4.U00 - o

2,000-

Of

4-

D4-

CIH-

(XNO D+

O CHO CH

o

Of

FRONT DOOR

REAR DOOR

O B PILLAR

Oh

O Of

0 3 +

L ± JL 10 2.0 3 0 4.0 50

INTRUSION DEFORMATION in

6.0 70

Figure 13 - LOAD VERSUS INTRUSION DEFORMATION AT THREE LOCATIONS

ON THE RIGHT SIDE OF VEHICLE A
T 1 f 1 1 1 1— 1 §

UJ


40

36 -

32

28

24

20

16

12

BEFORE CRUSH TEST

TEST

6 12

inches

16 20

Figure 17 - VERTICAL PROFILE OF B PILLAR FOR VEHICLE A RIGHT

SIDE BEFORE AND AFTER STATIC CRUSH TEST

22,000

20,000

18,000

16,000

1^000

I2.000|-

10,000

8,000

6,000

4,000O

2,000O

+• 0

-T" o

T—0-r

O +

+

. o

+

•o+ O VEHICLE B1 LEFT SIDE

~^ VEHICLE A RIGHT SIDE

J I I L

0.20 0.40 0.60 OBO I.OO 1.20 1.40 1.60

INTRUSION DEFORMATION, in.

FIture 19 -LOAD VERSUS DEFORMATION OF A PILLAR DURING STATIC CRUSH TEST VEHICLES A & B1
16,000

14,000-

12,000

10,000 -

8,000 -

6,000-

4,000

2,000-

-.0 2 n0 4 ^0 6 -0 8

RELATIVE DEFORMATION, In.

-.10

- RELATIVE DEFORMATION BETWEEN A AND B PILLARS VERSUS STATIC CRUSH

LOAD ON VEHICLE A LEFT SIDE
20,000

18,000*-

16.000

14.000-

I 2,000 -

IQOOO8,000-

6,00O4.000 -

2.000-4-

.05 .10 15 20

RELATIVE DEFORMATION, in

25 30

Figure 21 - RELATIVE DEFORMATION BETWEEN B AND C PILLARS VERSUS STATIC CRUSH

LOAD ON VEHICLE A RI6HT SIDE
26PO0 rill I 1

X

T

20,000 — +

18,000 —

16,000

14,000

-

12,000 -

10,000

8,000

6,000 -

4,000

2,000 -

n 1 11 1 1 -0.2 0 0.2 0.4 a6 0.6 1.0

RELATIVE DEFORMATION, in

re 22 - RELATIVE DEFORMATION BETWEEN B AND C PILLARS VERSUS

STATIC CRUSH LOAD FOR VEHICLE B1 LEFT SIDE

(Ql 'QV01
ea
Figure 26 - FIREWALL FOR VEHICLE "B-l" BEFORE (UPPER) AND AFTER (LOWER) STATIC CRUSH TEST
28,000

O 0.20 0.40 0£0 aeo l.00 1.20 1.40 L60 1.80

DEFORMATION OF SEAT, in.

Figure 27 - DEFORMATION OF FRONT SEAT DURING CRUSH TEST OF VEHICLE B1 LEFT SIDE
Figure 28 REGIONS OF LOCAL DEFORMATION FOR VEHICLE "A" AFTER STATIC CRUSH TEST

Figure 29 FRACTURE OF WELDED JOINTS AT BASE OF B PILLAR AFTER STATIC CRUSH TEST

OF VEHICLE "A- RIGHT SIDE
Figure 30 - BUCKLING DEVELOPED IN DASH DURING STATIC CRUSH TEST OF VEHICLE
12,000

10,000

8,000-

6,000-

4^000-

2,000-

.10 .20

DEFORMATION, in.

30 .40

Figure 31 - DEFORMATION BETWEEN B PILLARS VERSUS LOAD FOR CRUSH TEST OF VEHICLE A RIGHT SIDE
Figure 32 - DEFORMATION OF REAR DOOR SIDE (iUARD BEAM AFTER STATIC CRUSH TEST

OF VEHICLE "B 1"
gure 33 BUMPER DISPLACEMENT VERSUS DURATION OF IMPACT FOR DYNAMIC CRUSH TEST

OF VEHICLE C-1
Figure 34 - EXTERNAL SIDE DEFORMATION AFTER STATIC TEST OF VEHICLE "B -1"

(UPPER) AND DYNAMIC TEST OF VEHICLE "B-2" (LOWER)

Figure 36 - DEFORMATION OF REAR DOOR SIDE GUARD BEAM AFTER DYNAMIC CRUSH TEST

OF VEHICLE "B-2"