میثم معزی

Nowadays, the study of seemingly informal behaviors during different loading has paid the attention of researchers in various sciences. In previous years, due to various computational constraints, this type of behavior was abandoned. However, these behaviors have become very important with the widespread use of woven composites in other applications. One of these is the behavior of composites during the out-of plane wrinkling. The main aim of this paper is to investigate the geometry of this behavior to reduce its computational constraints. At first, the samples were subjected to the uniaxial bias extension test. In continue, images of three-dimensional deformation of the samples at different crosshead displacements were obtained. Different geometric parameters were measured by geometric study of deformations such as maximum wrinkle depth using digital image processing method. Finally the correlation of geometric parameters in different crosshead displacements with mechanical parameters such as Poisson’s ratio was calculated. Results shown that the Poisson's ratio decreases with increasing maximum wrinkle depth. This method can be used to predict the mechanical behavior of composites in new modes.