Multiscale analysis of reliability of MEMS devices

This project aims to develop a predictive probabilistic model for the strength statistics of poly-Si MEMS devices. The model is derived based on the first-passage analysis of stochastic processes. The statistical parameters are determined from stochastic quasi-continuum simulations, which capture the detailed failure mechanisms of poly-Si. The proposed model is validated by a series of high-throughput tension experiments that produce strength histograms for specimens of different sizes and shapes.

Probabilistic analysis of dynamic quasibrittle fracture

This research aims to develop a mesh insensitive stochastic computational model for predicting the failure behavior of quasibrittle structures under impact loading. The model introduces an intrinsic length scale to the probability distributions of the material constitutive properties. This length scale is physically determined by a stochastic micromechanical model, which takes into account the variability of microstructural properties. The model is validated by a set of high-velocity impact experiments on silicon carbide beams.

Stress-corrosion cracking in polymers

This project aims to develop a chemo-mechanical computational model for stress corrosion cracking (SCC) that can capture the interactions among the chemical diffusion process, chemical-induced material degradation, and static fatigue crack propagation. The model is validated through an experimental study of crack growth in high-density polyethylene in a corrosive environment. The model is extended to reliability-based design of polymer pipes for water and natural gas delivery.

Energy scaling in rock cutting

This project aims to address the fundamental question of energy scaling in rock cutting, i.e. the dependence of the specific energy on the depth of cut. The research will focus on the formulation of scaling laws for different failure regimes. Both continuum and discrete computational models will be developed to simulate the cutting process for different depths of the cut. The proposed scaling models will be experimentally validated by both the existing literature and the newly planned experiments.

Completed projects

[1] Mechanics-based reliability analysis of quasibrittle structures

[2] Stochastic computational modeling of progressive collapse of RC buildings

[3] Effect of stress singularities on energetic-statistical scaling of fracture of quasibrittle structures

[4] Mechanical and compaction properties of graphite nanoplatelets modified asphalt binders and mixtures

We gratefully acknowledge financial support from our research sponsors