Effect of material and geometry variations on beam under patch loading

This work was initiated to study the influence of geometry and material var iations on the structural response of an aluminum I-beam subjected to conce ntrated loading. The beam behavior was computed with a previously validated LS-DYNA model, and an analytical response surface expression for the maxim um load capacity was established. The deviation between the response surfac e estimate and the numerical analysis result was within 1.1%, and < 0.35% i n the most interesting parameter range. The probability distributions of al l the material parameters, the thicknesses, and the geometrical imperfectio ns were established on measurements from former works, and the code PROBAN was used to evaluate the influence of variability in the model parameters. It was found practical to separate two different cases: (1) one reflecting the variation occurring in a certain extrusion; and (2) the other indicatin g the scatter in a random batch. The first case was shown to give 20% highe r design capacity indicating that it may be attractive to improve the contr ol of the production process.