Stochastic finite element analysis of composites

Composite materials can have a large variation in material properties, especially in the transverse direction. This can cause difficulty when designing with these materials and may lead to overdesigning the material. Using finite element software, a model was created to simulate failure of composite materials in the transverse direction. Using micrograph images, a simulation of microstructures was generated based on fiber volume fraction and special positioning of fibers. Using a multi-level approach, the material properties were calculated in the micromechanical model. The comparison of the obtained elastic properties with rule of mixture revealed that the transverse properties are poorly predicted by rule of mixture. A mesomechanical model was then developed based on the material properties obtained from the micromechanics model. Using a progressive failure approach, each element could independently be disabled when the element fails, causing a simulated propagation of failed material. The results showed that failure follows a Weibull distribution consistent with experimental observation. The developed stochastic model will allow for infinite possibilities of failure replicating experimental findings.