Effect of notch size on the reliability of composite laminates based on stochastic finite element analysis and experimental investigation.

摘要

This work considers the reliability of notched composite laminates based on stochastic mechanics. The reliability of composite laminates with different notch sizes is evaluated using point stress criterion and average stress criterion. Reliability values are calculated based on the stresses developed over certain characteristic distances from the notch edge and the strength of the corresponding un-notched laminates. In practical applications, it is very difficult to achieve a perfect circular profile during the drilling operation on a composite laminate and also there is a possibility that the driven hole is offset from the desired location. These imperfections affect the reliability of the laminate. In the present work the perturbation in the circular profile of the hole is modeled using a hypotrochoid variation and further, the location of the hole center is modeled using a Gaussian random variable. Tests are conducted on specimens made of graphite/epoxy material to determine the material properties that are required for stochastic analysis. (Abstract shortened by UMI.)