Phenix

EYEBROW STRUCTURAL ANALYSIS

November 14, 1999

<jrarchuleta@lanl.gov>

505 665 2416

# index

####  TOPIC page

> **SECTION** 0 **EYEBROW PICTORIAL VIEWS -**
>
> **index 2**
>
> **assembly view 3**
>
> **side view 4**
>
> **bottom view 6**
>
> **socket 7**
>
> **SECTION** 1 **SUMMARY -**
>
> **report information 9**
>
> **general description**
>
> **discussion of analysis**
>
> **summary of stress analysis 10**
>
> **SECTION** 2 **GENERAL design notes 11**
>
> **eyebrow description 12**
>
> **design requirements 14**
>
> **material properties 14**
>
> **SECTION 3 LOADS 15**
>
> **design loads 16**
>
> **SECTION 4 REMOVABLE PLATFORM 20**
>
> **loads**
>
> **stress**
>
> **SECTION 5 PERMANENT PLATFORM 25**
>
> **loads**
>
> **stress**
>
> **SECTION 6 miscellaneous 32**
>
> **back brace**
>
> **socket**
>
> **guardrail**

![](media/image1.wmf)Figure 1 Eyebrow Assembly

Figure 2 Eyebrow assembly -side view

![](media/image2.wmf)

![](media/image3.wmf)

Figure 3 Eyebrow assembly\-\--back plate view \[looking up\]

![](media/image4.png)

Figure 4 bottom view of eyebrow

![](media/image5.wmf)

### FIGURE 5 SOCKET 

# 

# 

# SECTION 1

# SUMMARY 

# 

# SECTION 1 summary 

## REPORT INFORMATION

This report presents the structural analysis of the Eyebrow.

The report is divided into 6 sections. Each section, following the first
2 general information sections, presents the analysis of a component,
e.g. section 5 discusses results and depicts stress of the Permanent
Platform.

Results generally are shown as contour plots except where the loads and
reactions are shown. The maximum stress condition shown is normally the
VonMises or maximum bending principle stress given in psi units. Total
deflection or total displacement is given in inches.

Due to the nature of this report, color copies provide the only
satisfactory means of data scrutiny. In most cases the vast amount of
information generated has not been saved, except as color contour plots.

The finite element analysis was done by use of COSMOS/M, a software
package by Structural Research and Analysis Corporation.

## EYEBROW general description

The Muon FEE electronic equipment racks are located on a platform
attached to the Back Plate of the magnet. The assembly consists of 2
platforms; a Permanent Platform attached to the magnet, and a Removable
Platform that attaches to the Permanent Platform. The assembly is called
the Eyebrow which attaches to the Magnet's Back Plate.

## DISCUSSION OF ANALYSIS

Stress levels and loads shown in this report do not include safety
factors, i.e. loads and stresses are due to real loading and are not
increased by safety factors. The summary table shown in the section
below \[page 10\] gives maximum stress levels for actual 'real' loads,
but the margin of safety (MS) does include a safety factor of 4. Stress
levels of critical sections can be found in the figures included in the
report.

This scan of the members that comprise the structure shows the Eyebrow
is structurally sound. Stress contours of the Eyebrow are found in
Section 4 and Section 5. Local bolt attachments and higher loaded areas
are reviewed in Section 6.

## SUMMARY OF STRESS ANAYLYSIS

+--------+------------+------+--------+------+------------------------+
| **     | *          | *    | **     | *    | **Margin of Safety**   |
| Item** | *section** | *ele | stress | *All |                        |
|        |            | ment | -psi** | ow** |                        |
|        |            | numb |        |      |                        |
|        |            | er** |        | **   |                        |
|        |            |      |        | Stre |                        |
|        |            |      |        | ss** |                        |
+--------+------------+------+--------+------+------------------------+
| Rem    | Outer main | 62   | 582.8  | 33   | 13.1                   |
| ovable | Beam       |      |        | ,000 |                        |
| Pl     |            |      |        |      |                        |
| atform |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        | Inner main | 213  | 371    | 33   | 21.2                   |
|        | Beam       |      |        | ,000 |                        |
+--------+------------+------+--------+------+------------------------+
|        | cross beam | 408  | 479    | 33   | 16.2                   |
|        |            |      |        | ,000 |                        |
+--------+------------+------+--------+------+------------------------+
|        | platform   | 299  | 3,006  | 33   | 1.74                   |
|        | mounting   |      |        | ,000 |                        |
|        | bar        |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+
|        |            |      |        |      |                        |
+--------+------------+------+--------+------+------------------------+

# 

# 

# 

# 

# 

# section 2

# general notes 

# SECTION 2 general

## DESCRIPTION OF EYEBROW

The Eyebrow is located above the South Magnet and straddles the Back
Plate as shown in the accompanying figures \[figs 1-4\]. The Eyebrow is
supported at 6 attachment points, four\[4\] of these supports are
centered on the upper edges of the Back Plate and two \[2\] which
provide overturn stability, attach to the downstream face of the
backplate. All of the attachments are through a face plate containing 6
each 3/8 inch diameter bolts. For details of a typical brace see drawing
10Y226402-08

The Eyebrow geometry is shown in drawing 10Y226402-02. The Permanent and
the Removable Platforms are each approximately 24 inches wide by 24 feet
long and span the Eyebrow in the East-West direction. The Eyebrow's
maximum protrusion in the Z direction is 313.7 mm downstream of the Back
Plate. The Permanent Platform outer beam is in the same vertical plane
as the end of the doughnut. The upstream protrusion from the Back Plate
is 772.6 mm; hangs over the Lampshade.

Access to the Eyebrow is via an opening located in the northeast corner
of the Removable Platform

## DESIGN details

Both platforms are similar in construction, use standard structural
steel shapes and welded construction. The floor is made of ¼ inch raised
pattern steel plate. Guardrailing and 4 inch high toeboards are provided
around both platforms.

The Permanent Platform 10Y226402-03, is anchored to the Back Plate by
means of 2 diagonal braces (Back Brace) 10Y226402-08, 2 vertical struts
(Vertical Brace) 10Y226402-07 and 2 vertical load pads located on the
Inboard Socket 10Y226402-09.

The Removable Platform 10Y226402-05, extends upstream of the Back Plate
over the Lampshades and is attached by means of 6 square beams inserted
in sockets welded to the Permanent Platform. See drawing 10Y226402-01

Design detail Summary

i.  Two main steel beams (2x6) run the length (east-west) of each
    platform forming the perimeter structure. The 2x6 beams are
    rectangular hollow tubing, 2"wide x 6" high x 0.188"wall,.

ii. The ends (east and west ends) of the platforms are closed by square
    4x4 tubing and which are also used for attaching lifting lugs. The
    tubing is 4" x 4"x 0.188"wall x 24 inch long.

iii. Cross ribs between the 2 x 6 beams form the flooring support for
     the ¼ inch steel floor plate. These beams also provide framing
     around cutouts in the floor beneath the racks and serve as support
     for the floor splice joint. The cross ribs are 2x2 tubing (2"x 2" X
     .125"wall).

iv. Weld construction details

    1.  Cross members \[Sockets,10Y226402-09,10;cross ribs and lifting
        end beams\] are welded to the main beams. See 10Y226402-04,06.

    2.  Floor is spot weld to the main \[2 x 6\] beams and to the cross
        members.

    3.  Kick plate is 1/4 inch steel plate by 4 inch high, spot welded
        to floor.

v.  Back Brace (Diagonal) 10Y226402-08, are located at 1 meter spacing
    (east-west)off the magnet's center Z axis to provide turn-over
    stability. These braces protrude downstream (behind) the Back Plate.

    1.  Vertical load reaction pads are located at 4 places on the flats
        of the backplate at the top octant.

        a.  Vertical Brace (struts) 10Y226402-07,are located on the
            outboard ends (east-west) of the platform

        b.  Vertical and Back Brace are made from 4 x 4 x 0.1875 wall
            square tubing.

        c.  

vi. Square receivers (6 each) made of square 4x4 inch tubing are
    attached below the Permanent Platform to provide the sockets that
    join the platforms, see drawing 10Y226402-09,10.

vii. The Removable Platform is supported by six 3½"square tubing beams
     (3½ x3½ x ¼ thick) which insert into the sockets of the Permanent
     Platform. See Platform Mounting Bar 10Y226402-11.

viii. The platforms are retained to each other by 12 each 3/8 inch
      diameter bolts, cross bolting the 2x6 beams.

## DESIGN REQUIREMENTS 

The Permanent Platform provides a mounting location for

instrument racks and the Removable Platform provides working area for
installation, wiring and maintenance of the racks. The Removable
Platform can be separated from the Eyebrow to facilitate removal or
installation of the lampshades.

Three \[3\] racks are installed on the Permanent Platform. The
arrangement of the racks is shown in a frontal view in figure 1 or see
drawing 10Y226402-03 (all dimensions are metric). The racks are
positioned in the platform with the front and back sides facing
East-West.

Each Platform and its components shall be capable of supporting, without
failure, its own weight and at least 4 times the maximum intended load
applied or transmitted

## MATERIAL PROPERTIES 

The material selected for the design conforms to ASTM standard
specifications. The square and rectangular steel tubing shape is cold
formed per specification ASTM A500 Grade B which has a tensile yield
strength of 45,000 psi. This allowable is for either welded or seamless
tubing. The Sockets of the Permanent Platform use tubing per ASTM A500
grade A, with an allowable tensile strength of 58,000psi

The table below summarized the maximum allowable strength levels used
for Eyebrow design.

+-----------------+-----------------+-----------------+-----------------+
| **Property**    | **Allowable**   | **value in      | **value in      |
|                 |                 | psi**           | psi**           |
| #### ASTM 500   |                 |                 |                 |
|                 |                 | **GRADE B**     | **GRADE A**     |
+-----------------+-----------------+-----------------+-----------------+
| Tension         | Ft              | 45,000          | 58,000          |
+-----------------+-----------------+-----------------+-----------------+
| Yield           | Fy              | 33,000          | 42,000          |
+-----------------+-----------------+-----------------+-----------------+
| Shear           | 0.6Ft           |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Bearing         | 0.9Fy           |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

#  

# 

# 

# 

# 

# section 3

# general loading

# information 

# SECTION 3 loads and geometry

#### GEOMETRY

#### Finite Element representation of the Removable Platform and Permanent Platform is shown below.

![](media/image6.png)

figure 6 Removable Platform

## 

![](media/image7.jpeg){width="6.093055555555556in" height="4.89375in"}

## 

## 

## 

## 

figure 7 Permanent Platform

## 

## DESIGN LOADS

#### removable platform

The design condition assumes 12 apostles each weighing 250 pounds
standing on the Removable Platform during a photo session. This loading
transposes to 62.5 lbs/ft^2^ on the platform, which is more than the 50
lbs/ft^2^ recommended by OSHA for medium duty platforms. This loading is
applied to the cross beams as 14.5 lbs/inch; see figure 8.

The Removable Platform loads are transferred to the Permanent Platform
through 6 beam sockets, see figure 11

#### permanent platform

The electronic racks are assumed to weight 1000 pounds each. Loads are
introduced through the 2\*2 cross beams straddling the racks at 500 lbs.

Additional Permanent Platform Loads

Eyebrow structural weight is estimated as 2000 pounds, 1000 lbs for each
platform. Miscellaneous attached hardware is estimated at 2000 lbs;
cables, clamps, hoses, etc. Platform loading is 60 lbs/ ft^2.^

This additional loading is introduced by a 11.5 lbs/inch load on the
perimeter of the permanent platform.

See figure 13 for loads.

...

# 

# 

# LOADS summary:

a.  **Permanent Platform; see figure 13**

    i.  Three equipment racks: each at 1000 pounds. Load is introduced
        to the main beams through the 2x2 cross beams on either side of
        the floor cutout at 500 lbs each.

    ii. Structural weight, hung loads, platform loads and any
        miscellaneous: 11.5 lbs/inch

        1.  Eyebrow structural weight \[2000 lbs\] is distributed
            through the 2x6 beams; Removable Platform and Permanent
            Platform each weigh 1000 pounds.

        2.  Include 2000 pounds of Cable and miscellaneous hardware
            attached to the Permanent platform

        3.  Platform floor loading of 60 lbs/ft^2^

    iii. Loading at Sockets are reactions from Removable Platform. **see
         figure 11**

    iv. Reaction loads on the Magnet's Back Plate are through 2 vertical
        struts(vertical brace}, 2 Diagonal (Back Brace) struts and 2
        reaction pads on the back plate..

    v.  Attachment of the struts to the Eyebrow and Back Plate is
        through 6 each 3/8 inch diameter bolts. see drawing
        10Y226402-01.

    vi. 

b.  **Removable Platform see 10Y226402-05**

    i.  Use 12 apostles standing side by side each apostle weighs in at
        250 pounds. Load is spread from plate to 9 cross beams. Cross
        beams are loaded at 14.5 lbs/in to represent the apostle
        loading.

    ii. Loads are reacted through 6 forks that insert into sockets of
        the fixed platform.

# 

# 

# 

# 

# 

# section 4

# stress analysis

# Removable Platform

# SECTION 4 stress analysis

# Removable Platform

The figures below show the stress distribution, fig 8, and maximum
deflections, fig 10, of the Removable Platform. Figure 9 is a close-up
look at the maximum stress region.

Maximum stress of 3,006 psi occurs on the inner Platform Mounting Bar,
node 299. Maximum deflection is 0.0202 inches on the Main Platform Beam,
node 213. See summary table page 10 for margins of safety.

#### ![](media/image8.wmf) 

Figure 8 Removable Platform Stress.

![](media/image9.jpeg){width="5.997222222222222in" height="5.4in"}Figure
9 zoom view of Removable Platform stress pattern.

![](media/image10.jpeg){width="5.997222222222222in"
height="8.009722222222223in"}Figure 10 Deflections of Removable
Platform\`

![](media/image11.jpeg){width="5.997222222222222in"
height="6.427083333333333in"}

Figure 11 Reaction Loads at Sockets

# 

# 

# 

# 

# 

# section 5

# stress analysis

# Fixed Platform 

# SECTION 5 stress analysis

# Permanent Platform

# geometry 

![](media/image7.jpeg){width="5.993055555555555in"
height="3.9368055555555554in"}

figure 12 permanent platform FEM geometry

# loads

![](media/image12.jpeg){width="5.993055555555555in"
height="3.9368055555555554in"}fig 13 loads on Permanent Platform

**loading table**

Load Set 1 -- FROMPLTFM

Nodal Forces (on Point)

Load in pounds, positive Z is up.

node ident. load direction

ID Z

node 3 -1136. in pounds

4 -647

5 -805.8

10 453.

11 305.

12 331.

16 -1136.

17 -647

18 -805.8

23 453.

24 305.

25. 331\.

Nodal Forces (on Curve)

curve ID Z Y

53 -500. 0. in pounds

54 -500. 0.

55 -500. 0.

56 -500. 0.

57 -500. 0.

58 -500. 0.

Nodal Force per Length (on Curve)

ID Z Y

curve 1 -11.5 0. in pounds/inch

2 -11.5 0.

3 -11.5 0.

4 -11.5 0.

5 -11.5 0.

6 -11.5 0.

7 -11.5 0.

8 -11.5 0.

9 -11.5 0.

10 -11.5 0.

11 -11.5 0.

12 -11.5 0.

13 -11.5 0.

14 -11.5 0.

# stress

The figure below, fig 14, show the stress distribution of the Removable
Platform. Figure 15 is a close-up look at the maximum stress region.

Maximum stress of 8,045 psi occurs on the inner Socket.

figure 14 Permanent Platform stress

![](media/image13.jpeg){width="5.993055555555555in"
height="3.9368055555555554in"}this is

the time

that try

mens

souls

figure 15 Permanent Platform. Max stress region.

![](media/image14.jpeg){width="5.993055555555555in"
height="3.9368055555555554in"}8,045 max stress at inboard socket

# 

# section 6

# stress analysis

# Miscellaneous

Loads applied to the braces are shown below.

![](media/image15.jpeg){width="5.993055555555555in"
height="3.9368055555555554in"}

![](media/image16.png){width="5.625in"
height="4.177083333333333in"}figure 16. deflection of backbrace

figure 17 stress fringe of backbrace

![](media/image17.png){width="5.625in" height="4.177083333333333in"}

figure 18 backbrace mount stress pattern.

![](media/image18.png){width="5.625in" height="4.177083333333333in"}

![](media/image19.png){width="5.625in" height="4.125in"}

figure 19 Socket internal load transfer stress.