Capabilities and applications of probabilistic methods in finite element analysis

The ability to quantify the uncertainty of complex engineering structures subject to inherent randomness in loading, material properties, and geometric parameters, is becoming increasingly important in the design and analysis of structures. Probabilistic finite element analysis provides a means to quantify the reliability of complex systems in such areas as aerospace and automotive structures. However, for wide acceptance, probabilistic methods must be interfaced with widely used commercial finite element solvers, such as ABAQUS, ANSYS, and NASTRAN. In addition, the finite element results are generally post-processed to evaluate a measure of useful life with tools that can compute quantities such as fatigue life. In this paper, interfacing and performance issues involved in coupling probabilistic methods, commercial finite element solvers and post finite element solvers are discussed. An example problem consisting of an integration of the NESSUS probabilistic analysis software, the ABAQUS finite element solver and fatigue life assessment is used to demonstrate concepts.