1SCT End-Cap FDR 1/11/01C.J.Nelson

Inner Detector SCT End-Cap FDR Summary of Prototyping and FE Analysis

C.J.Nelson

Rutherford Appleton Laboratory, CLRC

Summary of documents; ATL-IS-EA-0001ATL-IS-ER-0041ATL-IS-TR-0011ATL-IS-TR-0003ATL-IS-EA-0002ATL-IS-EA-0001

2SCT End-Cap FDR 1/11/01C.J.Nelson

Skin laminate: Tensile Good result E=112 Gpa Strength = 400 MPa

Sandwich FWT Good result 2.5 - 3.9 MPa

4 Point Bend : Good correlation

ModelDir Test ValueSandwich

optionL 2575.9

2576.52638.2

2478.5

W 1333.71531.71623.3

1494

Prototyping and FE Analysis Sample tests

3SCT End-Cap FDR 1/11/01C.J.Nelson

Inspection of wing Frq test: Expt. Set-up

Prototyping and FE Analysis Prototype Wing

4SCT End-Cap FDR 1/11/01C.J.Nelson

Prototyping and FE Analysis Prototype Wing/ Modal Correlation

1

X

Y

Z

kwing2.txt: Korex wing

OCT 17 200118:49:21

ELEMENTS

TYPE NUM

UROT

Experimental FEMMode Comments Frequency Shape

1 10.4 Twist2 Very large relative amplitude 11.3 Twist 9.1 Hz 1st twisting

mode3 13.8 Twist4 Faint, partly confused pattern 16.6 Beat5 17.8 Beat 16.2 Hz beating

mode

5SCT End-Cap FDR 1/11/01C.J.Nelson

Prototyping and FE Analysis Structure FE Modelling

•ANSYS FEA -Shell 91 composite elements, 3 layers, ‘thick’ sandwich

Early Model~2500 elements-Coarse mesh-discs attached to cylinder-mass only 100 kgMax defl ~0.12mmNat freq ~8 Hz

6SCT End-Cap FDR 1/11/01C.J.Nelson

1

1112X

Y

Z

OCT 9 200118:34:26

ELEMENTS

Detailed Model~37 000 elements-Fine mesh where reqd.-accurate apertures-cylinder flanges-12 point disc attachment-Mass 168 kgMax defl ~0.5 mmNat freq ~6.4 Hz

Prototyping and FE Analysis FEA :Detailed model

7SCT End-Cap FDR 1/11/01C.J.Nelson

1

Detail of mesh at disc mounting positions

Prototyping and FE Analysis FEA :Detailed model

8SCT End-Cap FDR 1/11/01C.J.Nelson

1

1112X

Y

Z

gravity and temperatures

OCT 1 200117:42:00

AREAS

TYPE NUM

UROT

Model showing constraints under wing tips

Fixed (spatially as per plot)

Front Wing: Y, Z-rotation

Front Wing: X, Y, Z-rotation

Rear wing: Z,Y , X-rotation Y-rotation and Z-rotation

Rear wing: all 6 dofs

Prototyping and FE Analysis Model constraints

9SCT End-Cap FDR 1/11/01C.J.Nelson

1

MN

MX

1112X

Y

Z

gravity and temperatures for CTE

0.056761

.113522.170284

.227045.283806

.340567.397328

.454089.510851

OCT 13 200111:10:37

NODAL SOLUTION

STEP=1SUB =1TIME=1USUM (AVG)RSYS=0DMX =.510851SMX =.510851

1

MN

MX

1112X

Y

Z

gravity and temperatures for CTE

-.506757-.44949

-.392224-.334957

-.27769-.220423

-.163157-.10589

-.048623.008644

OCT 13 200111:13:26

NODAL SOLUTION

STEP=1SUB =1TIME=1UY (AVG)RSYS=0DMX =.510851SMN =-.506757SMX =.008644

Vertical deflections (mm) under gravity and operating temperatures

Predicted vector deflections (mm)

Prototyping and FE Analysis Load Case 1: Initial conditions -

Deflection

10SCT End-Cap FDR 1/11/01C.J.Nelson

Maximum Stresses

Component Figure Skin stress MPa Skin Allowables MPaMax VonMises MPa

31 at front wing mount -

Maximumprincipal

10, 11 18 front wing/ ITE + around apertures

200

Minimumprincipal

12 -35 at front wing mount -70

Sxy 6 45

Component Core stress MPa Core Allowables MPaSyz 0.045 disc 9 mounts 0.35Sxz 0.035 disc 9 mounts 0.5

N.b The allowables already have a factor of safety of 2

Overall margin of safety > 2

Prototyping and FE Analysis Load Case 1: Initial conditions -

Stresses

11SCT End-Cap FDR 1/11/01C.J.Nelson

Prototyping and FE Analysis Load Case 2: Initial conditions

including worst case CME;

Maximum Stresses

Component Skin stress MPa Location Skin AllowablesMPa

Max VonMises MPa

47 Alongside disc 9mount

-

Maximumprincipal

16 Front wing/ ITE 200

Minimumprincipal

-50 Alongside disc 9mount

-70

Sxy 7.5 On cylinder 45

Component Core stress MPa Location Core AllowablesMPa

Syz 0.26 Alongside disc 9mount

0.35

Sxz 0.23 Alongside disc 9mount

0.5

Overall, Margin of safety on allowables 30% (minimum principal stress)26% (core stress)

12SCT End-Cap FDR 1/11/01C.J.Nelson

Prototyping and FE Analysis Load Case 3: Temperature Variation

ConditionsUpper half of cylinder : 5 deg above expectedAll discs : 5 deg above expected

Direction Deflection of discs Short termrequirement

X 4 50 (r), 12 (r-phi)Y 7.7 50 (r), 12 (r-phi)Z 14.8 1000

Results

13SCT End-Cap FDR 1/11/01C.J.Nelson

Mode Frequency Description/ area affected1 6.4 Whole cylinder axial movement, wings bend2 24.1 Cylinder rotates about rear wing, front wing

bends up3 26.39 ITE only4 26.4 ITE only5 27.3 Discs 2, 3, 4 diaphragm6 27.32 Discs 5, 6 diaphragm7 27.4 Discs 2 - 6 diaphragm8 27.4 Discs 1, 3, 4 diaphragm9 28.5 All discs diaphragm10 29.1 Most discs diaphragm

Prototyping and FE Analysis Modal Analysis

Very similar modes to early model, but with extra mode for ITE

14SCT End-Cap FDR 1/11/01C.J.Nelson

Prototyping and FE Analysis Random Analysis

Direction Early model (100 Kg) Early model (136 Kg) Requirementr-phi 2.5 3.9 12

Z 36.7 45 1000Predicted 3 displacements (m)

Direction Requirement (m) Likely maximumInput psd 1x10-10 g2/ Hz

Worst caseInput psd 1x10-8 g2/ Hz

r-phi 12 0.25* 2.5*

Z 200 3.7 36.7*in any direction; X, Y or vector

Predicted 3 displacements (m) with 1% damping

The mass distribution and predicted modes of the detailed model are verysimilar to those for the reduced model, and it is expected that a random analysisof the detailed model will give very similar results.

Results from psd analysis of early model

15SCT End-Cap FDR 1/11/01C.J.Nelson

Tests have been done to confirm material properties and modelling

Prototyping has proved manufacturability of proposed sandwich with Korex

Detailed model confirmed early results Predicted deflections, stresses are

acceptable Structure is fit for purpose!

Prototyping and FE Analysis Conclusions