Cooperative application of holography and finite element modelingin determining critical vibration behavior of printed wiring boards

摘要

A PWB (printed wiring board) with dimensions of 6.5"×5.5"and attached with several bolts along the perimeter as constraints wasacoustically vibrated and studied using CAH (computer-aided holometry).The frequency and shape of the first (primary) and second resonantmodes, revealing the full field displacements and strains of the PWBs,were recorded automatically. Zero-displacement regions were alsorecorded for possible locations of strategic components. Finite element(FE) modeling using eigenvalue calculations was applied to correlatewith the CAH results. Adjusting the boundary conditions in the modelingeffort so as to match the experimental results proved to be the trickytask in the FE analysis since the mode shapes were extremely sensitiveto boundary constraints