PSI - Issue 14

G Vamsi Krishna et al. / Procedia Structural Integrity 14 (2019) 820–829 G. Vamsi Krishna / Structural Integrity Procedia 00 (2018) 000–000

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natural frequency of the complete assembly. To reduce the model size, internal construction details of the two subsystems are simplified for analysis, at the same time, retaining the construction details of all the components required for accurate simulation of mass and stiffness of the package assembly. Outer casings of both packages are modelled as they are, except for simplification/removal of details such as O ring grooves, bolt holes etc. Number of electronic components inside the outer casing of both packages are modelled as point masses, simulating their mass and CG location. These remote points are attached using rigid links to the faces inside the outer casing to which those components are attached in actual hardware as shown in Fig. 4.

Fig. 4: Components inside package, simulated as remote points

Honeycomb bracket is modelled using quadratic layered solid elements, SOLID186. Based on definition of hybrid construction - viz. thickness of face sheets, thickness of honeycomb, and number of elements defined through the thickness of bracket - the section data of each of layered SOLID186 elements viz. no. of layers, layer thickness, material and element orientation are defined by ANSYS. Mesh convergent study is carried out to arrive at appropriate element size for honeycomb bracket. Fixed boundary conditions is applied around the periphery of bracket and acceleration load of 600 / � is applied in the direction perpendicular to the plane of bracket. The FE model and boundary conditions are as shown in Fig. 5.

Fig. 5. (a): Boundary conditions and loading; (b) FE model

3.2. Numerical results:

3.2.1. Total displacement plot: