Structural Analyses of Spacecraft Electronic Packages

1992 ◽  
Vol 114 (1) ◽  
pp. 96-99
Author(s):  
S. Kannappan ◽  
V. Kunukkassril
Keyword(s):  
Finite Element ◽  
Random Vibration ◽  
Static Solution ◽  
Mode Shapes ◽  
Load Factor ◽  
Vibration Test ◽  
Electronic Packages ◽  
Circuit Boards ◽  
Test Conditions ◽  
Electronic Assemblies

The spacecraft electronic assemblies are subjected to severe environmental conditions during testing, launching and during orbit mission. The success of the mission depends upon the proper functioning of these critical electronic modules. The structural analyses using Finite Element Methods (FEM) assure the integrity of these components. A typical box, Array Drive Electronics (ADE), for TIROS satellites [1] is discussed in this article. The NASTRAN software was used to perform the stress and modal analyses of the box assembly with five circuit boards, covers and mounting feet. The stress analysis was performed for a static solution. As a conservative loading, 3 sigma load factor was used in the calculation of the acceleration values from the random vibration test conditions. Margins of safety were calculated. Design and material changes were recommended. The mode shapes fall in to three groups as explained in the text.

Identification of printed circuit boards mechanical properties using response surface methods

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Gharaibeh
Keyword(s):  
Finite Element ◽  
Response Surface ◽  
Material Properties ◽  
Printed Circuit Boards ◽  
Dynamic Testing ◽  
Mode Shapes ◽  
Fe Model ◽  
Circuit Boards ◽  
Content Type ◽  
Printed Circuit

Purpose This study aims to discuss the determination of the unknown in-plane mechanical material properties of printed circuit boards (PCBs) by correlating the results from dynamic testing and finite element (FE) models using the response surface method (RSM). Design/methodology/approach The first 10 resonant frequencies and vibratory mode shapes are measured using modal analysis with hammer testing experiment, and hence, systematically compared with finite element analysis (FEA) results. The RSM is consequently used to minimize the cumulative error between dynamic testing and FEA results by continuously modifying the FE model, to acquire material properties of PCBs. Findings Great agreement is shown when comparing FEA to measurements, the optimum in-plane material properties were identified, and hence, verified. Originality/value This paper used FEA and RSMs along with modal measurements to obtain in-plane material properties of PCBs. The methodology presented here can be easily generalized and repeated for different board designs and configurations.

Thermal Stresses in Layered Electronic Assemblies

1997 ◽  
Vol 119 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Z. Q. Jiang ◽  
Y. Huang ◽  
A. Chandra
Keyword(s):  
Finite Element ◽  
Thermal Stresses ◽  
Interfacial Shear Stress ◽  
Beam Theory ◽  
Accurate Method ◽  
Accurate Estimate ◽  
Electronic Packages ◽  
Package Design ◽  
Adhesive Layers ◽  
Electronic Assemblies

Thermal stresses in layered electronic assemblies are one of the causes of the mechanical failure of electronic packages. A simple but accurate method of estimating these thermal stresses is needed for the design of these packages. A simple approach based on beam theory exists, but it suffers from nonequilibrium of the peeling stress distribution. An improved method that overcomes this drawback is proposed here. For layered electronics with thin adhesives, simple analytical expressions are obtained for interfacial shear stress and peeling stress, as well as for other stress components. The finite element method is used to verify these solutions. It shows excellent agreement between the finite element results and these simple solutions, especially when the moduli of adhesive layers are significantly lower than the moduli of the other layers. This method provides an accurate estimate of thermal stresses for use in package design involving thin and compliant interface or adhesive layers.

scholarly journals Structural analysis of guyed mast exposed to wind action

2016 ◽  
Vol 20 (suppl. 5) ◽  
pp. 1473-1483 ◽  
Author(s):  
Milada Pezo ◽  
Vukman Bakic ◽  
Zoran Markovic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Analysis ◽  
Lattice Structure ◽  
Mode Shapes ◽  
Load Factor ◽  
Wind Action ◽  
The Stability ◽  
Guyed Mast ◽  
Element Method

The behavior of the mast is non-linear due to its slenderness and compliant guy-support system, having a tendency to lose stability and even crush suddenly. Wind load is one of the main factors affecting the stability of the structure of the mast. Structural assessment of the different mast configurations has been investigated in the past. Furthermore, European standards EN 1993-3-1:2006 and EN 1993-1-6:2007 already provides some guidelines about the basis of structural analysis of masts and towers. This paper presents the results of numerical simulations of a guyed mast exposed to wind action using finite element method. Structural analyses were performed for three different constant wind loads, modal analysis provides the values of natural frequency and mode shapes, while the stability analysis was performed for the first three buckling load factor values. The motivation for this study is to investigate the contribution of finite element method to structural analysis of a lattice structure such as guyed mast as an alternative and/or improvement to the literature and codes.

Design and Development of Vibration Testing Fixtures

2016 ◽  
Vol 4 (1) ◽  
pp. 08-11 ◽  
Author(s):  
Anjali Reddy ◽  
Hamsini K ◽  
Harsh. S. Petunias
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Random Vibration ◽  
Experimental Result ◽  
Mode Shapes ◽  
Vibration Testing ◽  
Element Analysis ◽  
Cad Models ◽  
Defense Research ◽  
The Right

This paper deals with the Design of Vibration Testing Fixtures for Random Vibration loads as specified by the MIL 810 military standards. Following selection of the right material and configuration of the fixtures, CAD models are generated and numerically checked for natural frequencies and mode shapes using Finite Element Analysis. Based on these results, the response of the fixtures to the MIL 810 standard Random Vibration profile input is measured using Finite Element Analysis and the transmissibility is calculated.Finally, the fixture is tested experimentally for to the MIL 810 standard Random Vibration profile input and based on these values; transmissibility of the fixture is computed. The experimental result is compared to the Finite Element results and thus, found that the fixture can be used for testing missile packages at the Defense Research and Development Laboratory (DRDL), Hyderabad.

The effect of vibration characteristics of an automotive seating system on ride comfort – A finite element study

2019 ◽  
Vol 233 (18) ◽  
pp. 6588-6601 ◽  
Author(s):  
M Ramalingam ◽  
D Davidson Jebaseelan
Keyword(s):  
Finite Element ◽  
Random Vibration ◽  
Vibration Mode ◽  
Ride Comfort ◽  
Spinal Column ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Element Analysis ◽  
Vibration Transmissibility ◽  
Random Vibration Analysis

The Automotive Seating System (ASS) is an important sub-system in a car for increasing the ride comfort of driver/occupant and hence the need for a systematic study on the vibration characteristics of ASS is of importance. The present study finds out the vibration characteristics of four models of automotive seating system, with and without dummy mass using finite element analysis. The vibration mode shapes such as lateral, fore-aft and twisting of automotive seating system found in the frequency range 0-80 Hz for the four models of automotive seating system and correlated with experimental results found in the literature. The natural frequency of the seat with dummy mass was found to be in the human discomfort zone of the spinal column (10–12 Hz) and abdomen (4–8 Hz). The vibration transfer to occupant body was studied at 11 positions, with unit acceleration given at four mounting locations of automotive seating system in three directions separately. The vibration transmissibility was found to be higher than one in seat backrest. The random vibration analysis was carried out to identify the acceleration level of automotive seating system, subjected to smooth and rough road excitations. In the case of rough road random excitations, the results of root mean square acceleration values in automotive seating system show that the driver/passenger feels “fairly comfortable”. This study emphasizes the importance of the ride comfort of driver/occupant. To enhance the ride comfort, the stiffness of seat structure has to be modified and suspension system has to be introduced.

Finite element analysis of a vibration test bed frame

2017 ◽  
Vol 59 (2) ◽  
pp. 183-187 ◽  
Author(s):  
Dong Lei ◽  
Rui Jiang ◽  
Pengxiang Bai ◽  
Feipeng Zhu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Test ◽  
Test Bed ◽  
Element Analysis

Improving the efficiency of cyclic devices for collecting and processing information in monitoring and vibration diagnostics systems

2017 ◽  
Vol 11 (1) ◽  
pp. 81-94 ◽  
Author(s):  
A. P. Moroz ◽  
T. S. Abbasova ◽  
M. E. Stavrovsky
Keyword(s):  
Random Vibration ◽  
Printed Circuit Boards ◽  
Monitoring Systems ◽  
Circuit Boards ◽  
Vibration Diagnostics ◽  
Printed Circuit ◽  
Impact Processes ◽  
Collection Device ◽  
Processing Information ◽  
Operation Characteristics

Identified the problem of increasing the efficiency of the collection device and the processing of information in telemetry monitoring systems and vibration diagnostics. The possibilities of CAD-programs for the calculation of vibro-impact processes and random vibration devices and printed circuit boards. A study of the frequency and random vibration study on the example of the PCB in SolidWorks environment. Abstract purpose, principle of operation, characteristics of the onboard telemetry information «Pyrite» system for measuring the parameters of aircraft, which are characterized by different phases and the duration of the flight telemetered site; It shows that the «Pyrite» equipment can be effectively used for the integrated telemetry information slowly evolving processes and rapidly changing processes of aircraft.

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