Professor Jialiang Le

Understanding the stochastic structural response is central to reliability-based engineering designs. Extended from the deterministic finite element (FE) method, stochastic FE modeling has become the most widely used simulation tool that has been applied to elastic and plastic analyses. A major research interest has recently been directed towards quasibrittle fracture, which is highly relevant to many modern engineering structures. Depending on the loading configuration and structural geometry, quasibrittle structures can exhibit complicated failure mechanisms, such as transition from diffused damage to localized damage, which are governed by different material length scales. Recent studies have shown that, without considering these length scales in modeling the random constitutive properties, stochastic FE simulation suffers a strong spurious mesh sensitivity. This severely limits the prediction capacity of the simulation. The motivation of this project is to address this fundamental problem. 

The goal of this research is to develop a new computational framework for stochastic analysis of quasibrittle fracture and failure. The framework is anchored by a seamless combination of the theory of random fields and the principles of quasibrittle fracture, which leads to a mechanism-based projection of random fields of constitutive properties onto the finite elements. The research will use Berea sandstone as a model material for the experimental validation. The proposed framework is universally applicable to other brittle and quasibrittle materials.