Finite element reliability analysis of inelastic dynamic systems
Jagannath, Mukundagiri K.
Master of Science
Due to the inherent uncertainties present in nature and given the imperfect state of our knowledge, it is impossible to guarantee the satisfactory performance of any system in an absolute sense. Therefore, an approach such as reliability based design, which offers a rational basis for taking into account in the design process the various sources of uncertainty and checking the computed probability of failure, is desirable. Structural reliability analysis also provides as a by-product various reliability sensitivity measures, which are very useful for rational decision making in structural design. In addition, the performance of large and complex structural systems can be predicted only through complicated numerical algorithms, such as the powerful finite element method. Hence, in order to evaluate the probability of failure of such systems for given limit-states or failure criteria, finite element analysis and reliability analysis must be linked together to produce the finite element reliability method. In this study, the link between a general purpose, research oriented, finite element program (FEAP) and a reliability analysis program (CALREL) is established. In order to realistically model the inelastic behavior of structural systems, several inelastic element routines are developed and implemented in FEAP. The algorithms required for computing accurately and efficiently the structural response gradient (needed in reliability analysis) with respect to basic material properties are also formulated and implemented in FEAP. Finally, finite element sensitivity and reliability analyses of several realistic structural examples are performed.