DESIGN OF A COMPOSITE STRUCTURE TO ACHIEVE A SPECIFIED RELIABILITY LEVEL

Safety factors are widely used in structural design. For composite mat erial structures, however, the lack of experimental feed-back does not allow the use of safety factors optimized from cost and reliability p oint of view. Reliability methods are one way to achieve the calibrati on of partial safety factors using a more rational method than judgeme nt alone. First we present the calibration process. The reliability me thods FORM, SORM, simulation, are initially applied to a laminate plat e under uniform pressure. In this example, we compare three design cri teria; the different reliability methods agree with the reference meth od for all criteria used. We chose the Tsai-Hill criteria and the FORM method to calculate safety factors. Then, a calibration process is un dertaken on a composite pipe and this serves to illustrate the differe nt steps in the calculation. Finally, we present a calibration of a ge neral plate structure. The partial safety factors and their sensitivit ies to the different parameters of the stochastic variables are given according to load type. (C) 1997 Elsevier Science Limited.