Liang Xue

Research Interests

Damage plasticity theory, Ductile fracture of solids, Computational mechanics

Current Research

Dr. Xue developed a new damage plasticity theory which is a generalization of the classical J2 plasticity theory by introducing an internal variable to quantify the progressive damaging process. The new theory incoporates the so-called "cylindrical decomposition" of damage. It consists of three main ingredients: a pressure sensitivity function, a Lode angle dependence function and a non-linear damage accumulation law. In addition to the damaging process, a weakening function is adopted to characterize the material deterioration of the matrix.

The classical plasticity theory becomes invalid when the plastic deformation is beyond moderate plasticity. The domain of validity of the new theory covers the entire range of the plasticity up to the fracture point. This model has been used to capture fracture modes of several classic tests, such as the cup-cone fracture of a tensile round bar, the slant fracture of a compact tension specimen and the tensile-shear transition of the three point bending of a rectangular bar etc. click here to see the Gallery.

The micro mechanical behavior of porous media is also considered. The Gurson-like material model has been extended to incorporate the void shearing mechanism. The void shearing has been demonstrated to be the dominant of damaging mechanism of simple shear failure and is responsible for the Lode angle dependence.