Multiscale modeling of micro-crack initiation to macro-fracture propagation

Brittle materials—such as concrete, rock, and ceramic composites—exhibit complex mechanical behavior at the meso-scale, including:

• Stress-induced damage and stiffness anisotropy,
• Nonlinear stress–strain relationships,
• Volumetric dilation caused by irreversible strain,
• Unilateral effects due to crack closure,
• A brittle-to-ductile transition under increasing confining stress,
• Distinct mechanical responses in tension and compression.

Physically, these effects arise from the nucleation and propagation of microcracks at grain boundaries and cross pore spaces. The growth and coalescence of these diffuse microcracks lead to the formation of localized macro-fractures and ultimately to structural failure. Accurately modeling this cross-scale process has been a long-standing challenge. The goal of this project is to:

• Formulate constitutive damage models that captures these behaviors using physically meaningful and identifiable material parameters,
• Develop algorithms and a theoretical framework to model the transition from microcrack evolution to macro-fracture formation,
• Implement the constitutive and cohesive fracture models within finite element codes using appropriate discretization techniques,
• Apply the computational framework to perform complete failure analyses of materials such as concrete, granite, and shale.

Related publications

1. W. Jin, C. Arson, (2017). Discrete equivalent wing crack based damage model for brittle solids. International Journal of Solids and Structures, 110: 279-293.
2. W. Jin, C. Arson, (2017). Micromechanics based discrete damage model with multiple non-smooth yield surfaces: theoretical formulation, numerical implementation and engineering applications. International Journal of Damage Mechanics, 27(5), 611-639.
3. W. Jin, H. Xu, C. Arson, S. Busetti, (2017). Computational model coupling mode II discrete fracture propagation with continuum damage zone evolution. International Journal for Numerical and Analytical Methods in Geomechanics, 41(2):223-250.
4. W. Jin, C. Arson, (2018). Nonlocal enrichment of a micromechanical damage model with tensile softening: advantages and limitations. Computers and Geotechnics, 94: 196-206.
5. W. Jin, C. Arson, (2018). Anisotropic nonlocal damage model for materials with intrinsic transverse isotropy. International Journal of Solids and Structures, 139, 29-42
6. W. Jin, C. Arson, (2019). XFEM to couple nonlocal micromechanics damage with discrete mode I cohesive fracture. Computer Methods in Applied Mechanics and Engineering, 357, 112617