Integration of a continuum damage model for shale with the cutting plane algorithm

Abstract

The stability of integration is essential to numerical simulations especially when solving nonlinear problems. In this work, a continuum damage mechanics model proposed by the first author is implemented with an integration method named cutting plane algorithm (CPA) to improve the robustness of the simulation. This integration method is one type of return mapping algorithm that bypasses the need for computing the gradients. We compare the current integration method with the previous direct method, and the result shows that the cutting plane algorithm exhibits excellent performance under large loading rate conditions. To enhance accuracy of the new method, a control procedure is utilized in the implementation of the algorithm based on error analysis. Thereafter, the theory of poromechanics is utilized with the damage model to account for the effects of fluid diffusion. Laboratory tests simulated with finite element method illustrate distinct behaviors of shale with different loading rates and indicate the development of microcrack propagation under triaxial compression. Error analysis.The error has been investigated on the stress changing for the same deviatoric strain loading. The test result with large strain is compared with the convergent test. The normalized

A thermodynamic damage model for 3D stress-induced mechanical characteristics and brittle–ductile transition of rock

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“…Geometric interpretation of cutting-plane algorithm in stress space (revised from Simo and Hughes, 1998; Xu and Prévost, 2017). …”

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Investigation of Coupled Processes and Impact of High Temperature Limits in Argillite Rock: FY17 Progress. Predecisional Draft

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