Drop/impact simulation and test validation of telecommunication products

Portable communication devices suffer impact-induced failure in usage. The products must pass drop/impact tests before shipment. The drop/impact performance is an important concern in product design. Due to the small size of this kind of electronic products, it is very expensive, time-consuming, and difficult to conduct drop tests to detect the failure mechanism and identify the drop behaviour. Finite element analysis provides a vital, powerful vehicle to solve this problem. The methodology of computer modeling, finite element method simulation and test validation techniques developed in ASMR at Motorola over the last two years are introduced in this paper. Two drop simulation and test validation cases in ASMR are reported in detail. The models are created with HYPERMESH, and the analysis is carried out with LS-DYNA3D. The analysis focuses on housing breakage, LCD cracking and structural disconnection under drop/impact shock. Apart from the computer simulation, a drop laboratory has been built in ASMR. With a customized drop tester, the drop orientation of the specimen can be controlled. The impact force relation to barrier, acceleration and strain inside the specimen during drop can be recorded in terms of time history curves. The test device, drop test and correlation of analysis and test data are illustrated in the paper. The simulation and test technology are applied to reliability identification and design support to Motorola's products.