Global and Local Coupling Analysis for Small Components in Drop Simulation

The failure induced in radio/phone drop often associate with the damage of inside small components or its tiny substructures. The difficulty to detect the failure in drop simulation is: i) the right drop-induced shock at the components must come from the simulation at whole- phone model; ii) the required output at the small components needs very fine local mesh, which causes unbearable CPU cost and make the simulation impossible. Mass-scaling technique is unsuitable for the case. A global-and-local coupling method is presented in this paper to solve the problem. The method is demonstrated by an example of a connector (global model in coarse mesh) to search stresses of its solder joints (local model). The displacement and stresses calculated by the method are correlated to the results from a finely meshed model. The correlation verifies good agreement of calculated displacement in the two models, and small difference of stress prediction. The source of the error and possible improvement are analyzed in the paper.