Finite-element based life prediction models

As of this writing, several finite-element based life prediction models have been proposed (Ref 1, 41) for SAC type alloys without Pb contamination. Some models feature primary and secondary creep of SAC solders, others ignore primary creep. According to recent, unpublished studies by this author, tertiary creep appears to be a significant deformation stage, but has not been considered in life prediction models. Moreover, existing models have not ex-... 

The comparison of finite element-based life prediction models suggest that the inelastic strain energy approach looks promising and may be more robust than the cyclic inelastic strain approach. However, the various models can be offset from each other depending on element sizes, time-steps and whether primary and tertiary creep of solders are accounted for or not. 

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