Reliability of inserts in sandwich composite panels

Inserts are commonly used to transfer loads to sandwich composite structures. Local stress concentrations due to inserts are known to cause structural failure, and experimental pull-out tests show that the failure load can vary by 20% between batches of sandwich panels. Clearly, uncertainty in the mechanical properties of the constituent materials needs to be addressed in the design and optimization of sandwich panel inserts. In this paper, we explore the utility of reliability analysis in design, applying Monte Carlo sampling, the First Order Reliability Method (FORM), line sampling, and subset simulation to a one-dimensional model of an insert in a homogenized sandwich panel. We observe that for systems with very low failure probabilities, subset simulation is the most efficient method for calculating the probability of structural failure, but in general, Monte Carlo sampling is more effective than the advanced reliability analysis techniques.