Title of Document: MODELING AND SIMULATION OF SHOCK AND DROP LOADING FOR COMPLEX PORTABLE ELECTRONIC SYSTEMS.

In this study, the transient response of electronic assemblies to mechanical loading encountered in drop and shock conditions are investigated. Many manufactures face design challenges when evolving new designs for high strain-rate life-cycle loading. Examples of high strain-rate loading include drop events, blast events, vibration, ultrasonic process steps, etc. New design iterations invariably bring new unexpected failure modes under such loading and costly trial-and-error design fixes are often necessary after the product is built. Electronics designers have long sought to address these effects during the design phase, with the aid of computational models. However, such efforts have been difficult because of the nonlinearities inherent in complex assemblies and complex dynamic material properties. Our goal in this study is to investigate the ability of finite element models to accurately capture the transient response of a complex portable electronic product under shock and drop loading. The portable electronic assembly in this study consists of a circuit card assembly in a plastic housing. Dynamic loading, consisting of broad-band vibration tests and shock tests on an electrodynamic shaker, and drop tests on a commercia