U.S. Department of 

Transportation

Federal Railroad 

Administration

HIGHER SPEED FREIGHT TRUCK: STRUCTURAL 

ANALYSIS

Office of Research

and Development

Washington, DC 20590

DOT/FRA/ORD-13/40 Final Report

October 2013

 
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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

October 2013

3. REPORT TYPE AND DATES COVERED

Technical Report

4. TITLE AND SUBTITLE

STRUCTURAL ANALYSIS: HIGHER SPEED FREIGHT TRUCK DESIGN FOR 

OPERATIONS OF UP TO 125 MPH

5. FUNDING NUMBERS

BAA-2010-1

DTFR53-11-C-00009

6. AUTHOR(S)

Sharma & Associates, Inc.

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Sharma & Associates, Inc.

5810 S. Grant Street

Hinsdale, Illinois 60521

8. PERFORMING ORGANIZATION 

REPORT NUMBER

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

U.S. Department of Transportation 

Federal Railroad Administration

Office of Railroad Policy and Development

Office of Research and Development

Washington, DC 20590

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

DOT/FRA/ORD-13/40

11. SUPPLEMENTARY NOTES

COTR: S. K. Punwani

12a. DISTRIBUTION/AVAILABILITY STATEMENT

This document is available to the public through the FRA Web site at http://www.fra.dot.gov.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

Sharma & Associates, Inc. (SA) had previously (2005–2009) developed a higher speed freight truck under sponsorship of the 

Federal Railroad Administration (FRA). Under the current contract, SA was tasked with developing performance requirements 

for higher speed freight trucks, as well as conducting structural and dynamics simulations according to those performance 

specifications. The strength of various components of the truck was assessed against specification M-213 of the Association of 

American Railroads’ (AAR) Manual of Standards and Recommended Practices (MSRP) using finite element analyses. The 

analyses showed that the prototype HST would meet the existing AAR structural strength performance requirements. The stress 

levels seen in the HST structure(s) were less than the corresponding allowable limits. 

On the basis of these analyses, SA is confident that the truck will meet the structural performance requirements for higher speed 

use.

14. SUBJECT TERMS

Higher speed freight truck, freight truck structural analyses, freight truck for 150 mph operation

15. NUMBER OF PAGES

27

16. PRICE CODE

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

20. LIMITATION OF ABSTRACT

NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. 239-18

298-102
ii

METRIC/ENGLISH CONVERSION FACTORS

ENGLISH TO METRIC METRIC TO ENGLISH

LENGTH (APPROXIMATE) LENGTH (APPROXIMATE)

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in)

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in)

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft)

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd)

1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE)

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2)

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2)

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2)

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres

1 acre = 0.4 hectare (he) = 4,000 square meters (m2)

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE)

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz)

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb)

1 short ton = 2,000 pounds 

(lb)

= 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg)

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE)

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz)

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt)

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt)

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal)

1 pint (pt) = 0.47 liter (l)

1 quart (qt) = 0.96 liter (l)

1 gallon (gal) = 3.8 liters (l)

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3)

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT)

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 3 4 5

Inches

Centimeters 0 1 2 3 4 5 6 7 8 9 10 11 12 13

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSIO

 -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 

°F

 °C -40° -30° -20° -10° 0° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°

For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

Measures. Price $2.50 SD Catalog No. C13 10286 Updated 6/17/98
iii

Contents

Executive Summary........................................................................................................................ 6

1. Background ............................................................................................................................. 7

2. Strength Requirements............................................................................................................ 9

3. Finite Element Model............................................................................................................ 10

3.1 Elements............................................................................................................................ 10

3.2 Materials ........................................................................................................................... 11

4. Finite Element Analyses........................................................................................................ 12

4.1 Load Cases........................................................................................................................ 12

4.1.1 Vertical Load Case............................................................................................. 12

4.1.2 Lateral Load Case .............................................................................................. 12

4.1.3 Longitudinal Load Case..................................................................................... 12

4.1.4 Combined Load Case......................................................................................... 12

4.2 Summary of Results.......................................................................................................... 13

4.2.1 Vertical Load Case............................................................................................. 13

4.2.2 Transverse Load Case ........................................................................................ 13

4.2.3 Longitudinal Load Case..................................................................................... 13

4.2.4 Combined Load Case......................................................................................... 13

5. Conclusions........................................................................................................................... 15

6. Recommendations for Future Work...................................................................................... 16

Appendix A. Figures—Vertical Load Case ................................................................................. 17

Appendix B. Figures—Transverse Load Case............................................................................. 19

Appendix C. Figures—Longitudinal Load Case ......................................................................... 21

Appendix D. Figures—Combined Load Case ............................................................................. 23

Abbreviations and Acronyms ....................................................................................................... 25
iv

Illustrations

Figure 1. A CAD view of the HST and an assembled prototype HST........................................... 7

Figure 2. 3D CAD Model of the H-Frame Truck Used for Finite Element Mesh........................ 10

Figure 3. Finite Element Model of the H-Frame Truck................................................................ 11

Figure 4. Finite Element Model Showing Applied Vertical Load................................................ 17

Figure 5. Finite Element Model Showing Constraint for the Vertical Load Case........................ 17

Figure 6. Vertical Loading—Nodal Stress Contour ..................................................................... 18

Figure 7. Vertical Loading—Areas of Local High Stress............................................................. 18

Figure 8. Finite Element Model Showing Applied Transverse Load ........................................... 19

Figure 9. Finite Element Model Showing Constraint for the Transverse Load Case................... 19

Figure 10. Transverse Loading—Nodal Stress Contour............................................................... 20

Figure 11. Transverse Loading—Areas of Local High Stress...................................................... 20

Figure 12. Finite Element Model Showing Applied Longitudinal Load...................................... 21

Figure 13. Finite Element Model Showing Constraint for the Longitudinal Load Case.............. 21

Figure 14. Longitudinal Loading—Nodal Stress Contour............................................................ 22

Figure 15. Longitudinal Loading—Areas of Local High Stress................................................... 22

Figure 16. Combination Loading—Nodal Stress Contour ........................................................... 23

Figure 17. Combination Loading—Areas of Local High Stress................................................... 24
v

Tables

Table 1. Applied Loads and Allowable Stress for Various Load Cases......................................... 9

Table 2. Predicted Stress Levels Compared to Allowable Limits................................................ 14
6

Executive Summary

The Federal Railroad Administration (FRA) had previously (2005–2009) contracted Sharma & 

Associates, Inc. (SA) to design and develop a railway truck for higher speed freight operations. 

As part of that work, vehicle dynamic simulations were conducted to predict the truck’s dynamic 

lateral stability, or hunting performance, for operations up to 150 miles per hour (mph). In 

addition, track worthiness simulations were carried out for pitch and bounce, twist and roll, and 

curving dynamics per the Association of American Railroads’ (AAR) Manual of Standards and 

Recommended Practices (MSRP), Section C-II, Chapter 11 Service-Worthiness Tests and 

Analyses for New Freight Cars.

Under the current contract (BAA-2010-1), SA was tasked with developing structural strength 

and dynamic performance requirements for this truck, carrying out structural and vehicle 

dynamics simulations according to AAR MSRP requirements, and conducting a market analysis 

of business opportunities that could arise from the availability of such a truck where

implementation of higher speed passenger service is concerned.

This report presents the truck structural analyses portion of the project. The strength of various 

components of the truck was assessed against proposed requirements using finite element 

analyses. Specification M-213 of the AAR MSRP prescribes the strength requirements of onepiece fabricated steel truck frames for freight equipment. SA determined that these prescribed 

requirements would be ideal for assessing the truck frame strength of the High Speed Truck 

(HST) prototype. In addition, SA determined load cases for other HST structural components to 

verify their respective strengths under expected operating conditions.

The analyses showed that the prototype HST would meet the existing AAR structural strength 

performance requirements. The stress levels seen in the HST structure(s) were below the 

corresponding allowable limits. On the basis of these analyses, SA is confident that the truck 

will meet the structural performance requirements for higher speed use.
7

1. Background

In a previous project sponsored by FRA (DTRS57-04-C-10023, Advanced Truck for High Speed 

Freight Operations), SA developed a higher speed freight truck design. Vehicle dynamic 

simulations were conducted to predict the truck’s dynamic lateral stability, or hunting 

performance, for operations up to 150 mph. Track worthiness simulations were also carried out 

to assess pitch and bounce, twist and roll, and curving dynamics per AAR MSRP guidelines, 

Section C-II, Chapter-11 Service-Worthiness Tests and Analyses for New Freight Cars.

The AAR MSRP requirements define the analyses regimes (i.e., track defect amplitudes and 

shapes and speeds for freight operations up to 80 mph (FRA Class 5 Track) only). Figure 1 

(below) shows a Computer Aided Design (CAD) model of the final design and a prototype that 

was tested in the yard track.

Based on the design developed in Phase I, two prototype trucks were manufactured and fitted 

under Amtrak mail/baggage cars. In Phase II of the project, the trucks were then tested at slow 

speeds in a yard environment for verification of overall design and fitment.

Figure 1. A CAD view of the HST and an assembled prototype HST

Under BAA-2010-1, Contract No: DTFR53-11-C-00009, SA was awarded a project to further 

the development of this higher speed freight truck. The project scope called for three distinct 

tasks:

1. Develop specifications for structural and vehicle dynamic performance.

2. Conduct stress analysis and vehicle dynamics simulations per AAR MSRP specifications.

3. Conduct a market analysis for higher speed railroad freight business opportunities when 

considering implementation of higher speed passenger lines.

Finite element analyses were conducted to determine the strength of the truck’s H-Frame. In a 

previous phase of the higher speed truck development, SA had evaluated structural performance 

using simplified analytical models and the requirements outlined in Table 4.1 of the AAR 

MSRP, Section S, page S [M-213] 292. The intent of the current task was to confirm structural 
8

integrity by conducting detailed finite element analyses with the appropriate analytical tools. SA 

used HyperMeshTM and ANSYS MechanicalTM to determine the strength of the H-Frame truck 

based on M-213 specifications.

This document reports the freight truck’s structural analyses carried out as a part of Task 2 of the 

BAA-2010-1 contract.
9

2. Strength Requirements

AAR MSRP M-213 specifications prescribe the vertical load P shown in Table 1 as the basis for 

design and testing. For the higher speed truck, based on the journal size of 6 x 11 inches, the 

vertical load P is 101,000 pounds (lb). Table 1 summarizes the design loads and maximum 

allowable stresses provided in M-213. The design criteria are fairly conservative given that the 

stresses are being restricted to 30 percent of the yield strength and are intended to provide 

assurance of good performance under both strength and endurance conditions.

Table 1. Applied Loads and Allowable Stress for Various Load Cases

Load Case Description Load Allowable Stress

1 Vertical P = 101,000 lb 30% of YS = 14,100 psi

2 Longitudinal 0.25P = 25,250 lb 30% of YS = 14,100 psi

3 Transverse 0.20P = 20,200 lb 30% of YS = 14,100 psi

4 Combination Vertical—101,000 lb

Longitudinal—25,250 lb

Transverse—20,200 lb

38% of YS = 17,860 psi

YS = Yield strength of respective materials

The H-Frame was fabricated using steel plates with the following material properties:

1-inch plates—Structural steel with YS = 47,000 psi, 22% elongation in 2 inches

1⁄2-inch plates—Structural steel with YS = 47,800 psi, 33% elongation in 2 inches
10

3. Finite Element Model

The 3D CAD model of the truck was first imported into HyperMeshTM. The CAD model is 

shown in Figure 2 below. For components made out of relatively thin plates, shell elements

ideally represent the structure. To define these shell elements, the midsurfaces of all components 

were first extracted, and junctions between all components were treated to ensure proper joint 

definition.

Figure 2. 3D CAD Model of the H-Frame Truck Used for Finite Element Mesh

3.1 Elements

Once the midsurface geometry was created with proper connectivity, the surfaces were meshed. 

Quad-element SHELL 63 was primarily used for the mesh, along with some “triangular”

elements at transition points. The finite element mesh developed for the H-Frame is shown in 

Figure 3 on the following page. 

The finite element model consisted of 58,572 nodes and 59,527 shell elements.
11

Figure 3. Finite Element Model of the H-Frame Truck

3.2 Materials

The H-Frame was made with steel plates. The bolster was fabricated from 1-inch-thick plates. 

The plates used for the gussets and brackets on the side frame were also 1-inch thick. The top 

and bottom plates of the side frame were made from 1⁄2-inch-thick plates, while the side plates of 

the side frame were 1-inch thick. The center bowl was made from a 7⁄8-inch plate. All the 1-

inch-thick plates used in the fabrication of the H-Frame were made of structural steel with yield 

strength of 47,000 psi. Appropriate material properties and thicknesses were assigned to all the 

elements of the finite element model.
12

4. Finite Element Analyses

4.1 Load Cases

For analyzing the H-Frame, individual load cases and corresponding constraints are defined in 

the finite element model. For this evaluation, four different load cases were analyzed: vertical, 

longitudinal, transverse, and combination. Loads for the various load cases are described in the 

design section of M-213 (Pages S [M-213] 291-292) and also listed in Table 1. The constraints 

used were according to those shown in M-213 (Pages S [M-213] 294-295) loading diagrams for 

static tests.

4.1.1 Vertical Load Case

A total vertical load of 101,000 lb (P) was applied on the brackets of the H-Frame that connect to 

the spring yokes. The total load was evenly distributed to all the effective nodes of the brackets,

as shown in Figure 4 in Appendix A. The bolster center plate was constrained in all three 

directions to simulate the center plate connection with a car center bowl. The vertical load 

constraint is shown in Figure 5 in Appendix A.

4.1.2 Lateral Load Case

A total transverse load of 20,200 lb (0.20P) was applied on the outer web of the side frame 

spread over a 4 x 4-inch block located at the longitudinal centerline of the truck and at the base 

of the side frame vertically. The load was evenly distributed to all the nodes in this block area,

as shown in Figure 8 in Appendix B. The transverse load was reacted along two line locations 

on the opposite side frame, as shown in Figure 9 in Appendix B. These reaction points were 40 

inches away from the longitudinal centerline of the truck.

4.1.3 Longitudinal Load Case

A total longitudinal load of 25,250 lb (0.25P) was applied on the outer web of the bolster spread 

over a 4 x 4-inch area located at the transverse centerline of the truck and at the base of the 

bolster vertically. The load was evenly distributed to all the nodes in the designated area, as 

shown in Figure 12 in Appendix C. The longitudinal load was reacted at the opposite four 

corners of the truck (side frame), as shown in Figure 13 in Appendix C. 

4.1.4 Combined Load Case

For the combined load case, the above three load cases and their corresponding constraints were 

applied simultaneously. The individual loads and constraints for this case are described in the 

previous sections. 
13

4.2 Summary of Results

The finite element model of the H-Frame, along with the loads, constraints, and load 

combinations, was imported into ANSYS and solved using linear static analyses. Upon 

completion of the analyses, results for the various load cases were post-processed. The 

following subsections describe the results of each load case.

4.2.1 Vertical Load Case

The nodal stress (von Mises equivalent stress) contour plot for the vertical loading case is shown 

in Appendix A, Figure 6. As can be seen from this plot, the stress levels are generally under the 

limits, except for a few local areas of high stress. This high stress area is mainly restricted to the 

bend radius of the top flange plate of the bolster near the center plate (Figure 7). High peak 

stresses generally result from singularities introduced by mid-surface and joint approximations. 

For this reason, AAR MSRP M-1001 C-II (page C-II [M-1001] 308) recommends that, for 

fatigue life calculations, stress values at a distance of four times the thickness of the parent 

material be used. Following this recommendation, SA certified that all the stresses in the HFrame (away from all the joints) were within the allowable limit of 30 percent of yield strength 

(14,100 psi).

4.2.2 Transverse Load Case

The von Mises stress contour plot for the transverse loading case is shown in Appendix B, Figure 

10. As can be seen in Figure 11, there are two local high stress locations (nodes); however, 

using the AAR MSRP M-1001 recommendation, the stresses in the H-Frame are well within 

allowable limits.

4.2.3 Longitudinal Load Case

The von Mises stress contour plot for the longitudinal loading case is shown in Appendix C, 

Figure 14. As can be seen, there are a few local areas of high stress in the region of the load 

application. Figure 15 shows the areas of higher stress on the bolster web. The applicable 

stresses in the H-Frame are well within the allowable limit of 30 percent of yield strength 

(14,100 psi).

4.2.4 Combined Load Case

The von Mises stress contour plot for the combination loading (vertical, longitudinal, and 

transverse) case is shown in Appendix D, Figure 16. As seen in Figure 17, there are a few areas 

of high local stresses, specifically along the bend radius of the top flange plate of the bolster; 

however, the applicable stresses in the H-Frame are well within the allowable limit of 38 percent

of yield strength (17,860 psi).

The load case with the combined loads has addition deflection constraints applied, reflecting a 

combination of test support conditions defined inn M-213; these additional deflection constraints 

result in slightly lower stresses under the combined load case in comparison with the other cases.
14

Table 2 below provides a concise summary of the final results.

Table 2. Predicted Stress Levels Compared with Allowable Limits

Load 

Case

Description Load Allowable 

Stress

Predicted Stress

1 Vertical P = 101,000 lb 14,100 psi 13,500 psi

2 Longitudinal 0.25P = 25,250 lb 14,100 psi 12,600 psi

3 Transverse 0.20P = 20,200 lb 14,100 psi 12,400 psi

4 Combination Vertical—101,000 lb

Longitudinal—25,250 lb

Transverse—20,200 lb

17,860 psi 12,186 psi

*4T—Four times the thickness of the parent material away from joints
15

5. Conclusions

Based on the detailed finite element analyses performed using HyperMeshTM and ANSYSTM, it is 

evident that the H-Frame of the high-speed truck performs well under the loading requirements

specified in AAR MSRP M-213. Overall, the stresses in the components of the H-Frame are 

within allowable limits. Therefore, the prototype HST is expected to offer good structural 

performance.
16

6. Recommendations for Future Work

Although fatigue is not expected to be a concern, given that the stress levels are low and 

generally under the endurance limits, a detailed fatigue evaluation would increase confidence in 

the strength of freight truck performance. The best practices in fatigue analyses recommend use 

of expected load time histories for more accurate fatigue life prediction. SA recommends 

performing a full fatigue evaluation of the trucks’ components after a field test that allows 

collection of load history.
17

Appendix A. 

Figures—Vertical Load Case

Figure 4. Finite Element Model Showing Applied Vertical Load

Figure 5. Finite Element Model Showing Constraint for the Vertical Load Case

Vertical Load Application

Vertical Load Constraint
18

Figure 6. Vertical Loading—Nodal Stress Contour

Figure 7. Vertical Loading—Areas of Local High Stress
19

Appendix B. 

Figures—Transverse Load Case

Figure 8. Finite Element Model Showing Applied Transverse Load

Figure 9. Finite Element Model Showing Constraint for the Transverse Load Case

Transverse Load Application

Transverse Load Constraint
20

Figure 10. Transverse Loading—Nodal Stress Contour

Figure 11. Transverse Loading—Areas of Local High Stress
21

Appendix C. 

Figures—Longitudinal Load Case

Figure 12. Finite Element Model Showing Applied Longitudinal Load

Figure 13. Finite Element Model Showing Constraint for the Longitudinal Load Case

Longitudinal Load Application

Longitudinal Load Constraint
22

Figure 14. Longitudinal Loading—Nodal Stress Contour

Figure 15. Longitudinal Loading—Areas of Local High Stress
23

Appendix D. 

Figures—Combined Load Case

Figure 16. Combination Loading—Nodal Stress Contour
24

Figure 17. Combination Loading—Areas of Local High Stress
25

Abbreviations and Acronyms

AAR Association of American Railroads

CAD Computer Aided Design

FRA Federal Railroad Administration

HST Higher Speed Truck

MSRP Manual of Standards and Recommended Practices

SA Sharma & Associates, Inc.