Effect of material in-homogeneity on reliability

Material in-homogeneity has strong effect on mechanical component reliability. A new method, based on the Monte-Carlo simulation technique, is introduced to analyse the effect of material inhomogeneity on mechanical component reliability. The results have shown that the bigger the mechanical component is, the worse its reliability becomes. This particular analysis method can be incorporated into the failure analysis module to predict failure probability.

Question

Consider the case of two bars A and B that have the same cross section, the same axial compression-load (F) and the same material but they have different lengths as shown in the following figure.

reliability_05.gif

both bars have the same stress and strengths.   The question is which bar is more reliable or which has the greater chance of failure?

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