1. PACS Structure Analysis1 PACS IBDR 27/28 Feb 2002 PACS Housing: Structure Analysis Dr. G. Wanderer CASE GmbH

2. PACS Structure Analysis2 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

3. PACS Structure Analysis3 PACS IBDR 27/28 Feb 2002 Dynamic and Static Loads Quasistatic: 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 g 2 /Hz 300 - 2000 Hz -6 dB/Oct

4. PACS Structure Analysis4 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

5. PACS Structure Analysis5 PACS IBDR 27/28 Feb 2002 Spectrometer Housing Spectrometer Housing is the highest loaded part except Suspension Stresses in Spectrometer Housing:

6. PACS Structure Analysis6 PACS IBDR 27/28 Feb 2002 Spectrometer Housing

7. PACS Structure Analysis7 PACS IBDR 27/28 Feb 2002 Pins And Bolts

8. PACS Structure Analysis8 PACS IBDR 27/28 Feb 2002 Notching of Vibration Loads Accelerometer- Positions with good correlation to I/F Forces

9. PACS Structure Analysis9 PACS IBDR 27/28 Feb 2002 Monitoring of I/F Loads I/F Loads for constant 1g Sine Reference Grid 13136

10. PACS Structure Analysis10 PACS IBDR 27/28 Feb 2002 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

11. PACS Structure Analysis11 PACS IBDR 27/28 Feb 2002 1-Axis Suspension

12. PACS Structure Analysis12 PACS IBDR 27/28 Feb 2002 Forces in Suspensions

13. PACS Structure Analysis13 PACS IBDR 27/28 Feb 2002 1 axis Suspension •critical load path through pin of diameter 10mm (shear)   = F/(2*A) = 7975N/(2*78mm 2 ) = 50,8N/mm 2 •s = F*l/8W = 7975N*6mm / (8*98mm 3 ) = 60,9 N/mm 2 •sMises = 107 MPa