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