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A CAE simulation methodology was developed to predict the warpage and shape deviation from nominal in finished plastic sub-assemblies that are joined using Infra-Red (IR), hot-plate or vibration welding processes. An automotive glove box bin and door sub-assembly was used to develop the methodology. It was seen that part warpage from injection molding and welding causes warpage in final assembled product which results in gaps and the consequent loss in quality of appearance. The CAE simulation methodology included prediction of the part warpage with residual stress from the injection molding process, use the post-molded shape as an initial part condition for the welding process, and simulation of the welding process itself.

The thermal efficiency of an internal combustion engine at steady state temperatures is typically in the region of 25-35%[1]. In a cold start situation, this reduces to be between 10% and 20% [2]. A significant contributor to the reduced efficiency is poor performance by the engine lubricant. Sub optimal viscosity resulting from cold temperatures leads to poor lubrication and a subsequent increase in friction and fuel consumption. Typically, the engine lubricant takes approximately twenty minutes [3] to reach steady state temperatures. Therefore, if the lubricant can reach its steady state operating temperature sooner, the engine's thermal efficiency will be improved. It is hypothesised that, by decoupling the lubricant from the thermal mass of the surrounding engine architecture, it is possible to reduce the thermal energy loss from the lubricant to the surrounding metal structure in the initial stages of warm-up.