PACS Structure Analysis 1

PACS IBDR 27/28 Feb 2002

PACS Housing: Structure Analysis

Dr. G. WandererCASE GmbH

PACS Structure Analysis 2

PACS IBDR 27/28 Feb 2002

Loads Strength Analysis of Housing Parts

Housing Pins and Bolts

Notching of Sine- and Random Qualification Loads

Suspension Analysis Brackets Pins and Bolts

PACS Structure Analysis 3

PACS IBDR 27/28 Feb 2002

Dynamic and Static LoadsQuasistatic: LC1 longitudinal 20g, lateral 2g

LC2 lateral 14 g

Sine Vibration longitudinal 5- 40 Hz 20g

40-100 Hz 10g

lateral 5-100 Hz 14g

Random Vibration 20 - 100 Hz +6 dB/Oct

100 - 300 Hz 0,05 g2/Hz

300 - 2000 Hz -6 dB/Oct

PACS Structure Analysis 4

PACS IBDR 27/28 Feb 2002

Material

The PACS Housing is build of AW 6061T6,

Bolts and Pins are of Typ A4-70 (i. e. Steel AISI 316)Ref: MIL HDBK-5H, ESACRACK user´s manual

Property at RT at 4K UnitE-Modulus 68260 78500 N/mm2G-Modulus 26200 30130 N/mm2Density 2710 2710 kg/m3Ultimate Strength 289 430 N/mm2Yield Strength 241 325 N/mm2CTE 24,0 14,4 10-6 1/K

Property at RT at 4K UnitE-Modulus 216000 240000 N/mm2G-Modulus 83000 91000 N/mm2Density 7900 7900 kg/m3Ultimate Strength 700 1448 N/mm2Yield Strength 450 545 N/mm2CTE 15,4 10,4 10-6 1/K

PACS Structure Analysis 5

PACS IBDR 27/28 Feb 2002

Spectrometer Housing

Spectrometer Housing is the highest loaded part except Suspension

Stresses in Spectrometer Housing:

Load Case Stress [MPa]LC1 75,9LC2 76,2Sine Qual. X 63,5Sine Qual. Y 197,0Sine Qual. Z 197,1Random Qual X 228Random Qual Y 182Random Qual Z 274

M.o.S yield 325

2741,110,08

M.o.S ult. 430

2741,510,04

PACS Structure Analysis 6

PACS IBDR 27/28 Feb 2002

Spectrometer Housing

PACS Structure Analysis 7

PACS IBDR 27/28 Feb 2002

Pins And BoltsLoad Case Axial Force Shear Force

Sine X 687 522Sine Y 837 567Sine Z 1988 1046Random X 1155 1326Random Y 1648 1162Random Z 2343 1330

Part Material Thickness CTEBolt M6 A4-70 10.4Washer A4-70 1.6 mm 10.4Flange AW 6061T6 6 mm 14.4Insert

Tightening Moment 8.3+/- 0.5 NmAxial Force +/-2577 N Shear Force 1464.00 N

Temperature Range -269°C ... 20°C

Nominal Diameter 6.00 mmPitch Diameter 5.35 mmCore Diameter 4.77 mmStress Cross Section 20.12 mm2Clamp Length 7.60 mmElastic Resilence of Bolt 5.30E-06 mm/NElastic Resilence of Clamped P. 2.02E-06 mm/N

Tightening Force 1325.9 ... 6062.21 N Force Loss due to Settings 413.00 N Force Loss due to Temperature 2166.00 N

TighteningAxial Stress 301.25 N/mm2Torsional Stress 169.88 N/mm2Equivalent Stress 421.11 N/mm2Yield utilization factor 0.94

Axial LoadAxial Stress 315.96 N/mm2Torsional Stress 169.88 N/mm2Equivalent Stress 431.76 N/mm2Stress Amplitude 14.71 N/mm2Fatigue Limit 61.5 N/mm2

M.o.S (yield) 0.79M.o.S (ultimate) 11.64M.o.S (fatigue) 3.18

Friction in Thread 0,15 .. 0,25Friction between clamped parts0,4 (A l/A l)

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PACS IBDR 27/28 Feb 2002

Notching of Vibration Loads

Accelerometer- Positions with good correlation to I/F Forces

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PACS IBDR 27/28 Feb 2002

Monitoring of I/F Loads

I/F Loads for constant 1g Sine

Reference Grid 13136

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Notch Procedure an accelerometer is located on the FPU at a place that the measured values correspond

to the interface loads

the notch calculation is based on the FE results scaled to the measured damping values for the major natural modes.

random vibration: the equivalent force is calculated for each major natural mode by integrating the

Force Power Spectral Density (PSD) around the mode The 4-sigma response is limited to the static load level for each major natural

mode. The notch width shall be smaller than 1/3 octave around the natural frequency. The slope of the notch shall be as steep as possible (more than 24dB/Oct, typical

50dB/Oct).

sine vibration: the output is limited to the calculated static interface force in the frequency range

50 to 100 Hz

PACS Structure Analysis 11

PACS IBDR 27/28 Feb 2002

1-Axis Suspension

PACS Structure Analysis 12

PACS IBDR 27/28 Feb 2002

Forces in Suspensions

1 axis fixation 2 axis fixation 3 axis fixationFx Fx Fy Fx Fy Fz

4467 4343 665 6342 190 15233912 2323 5033 1379 5293 16062085 1432 936 1969 753 118126549 6893 3620 9151 3751 78737975 6963 8464 5069 8727 130665019 5084 3687 4490 4724 13066

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PACS IBDR 27/28 Feb 2002

1 axis Suspension

critical load path through pin of diameter 10mm (shear)

= F/(2*A) = 7975N/(2*78mm2) = 50,8N/mm2

s = F*l/8W = 7975N*6mm / (8*98mm3) = 60,9 N/mm2

sMises = 107 MPaM.o.S yield 450

1071,112,8

M.o.S ultimate 700

1071,513,3