大理岩三点弯曲梁弹塑性损伤破坏研究

在应变空间内,推导出弹塑性损伤增量本构方程,通过自编程序实现该本构方程,同时将此程序实现了并行算法;建立了三点弯曲梁二维及三维细观尺度数值试样,分别进行相应地弹塑性损伤破坏数值模拟,作了相应的对比分析,在数值模拟中,提出破坏单元网格消去法,模拟裂纹扩展。研究发现:数值试验同物理试验较吻合,且与理论分析是一致的;由于三维试样细观单元的非线性比二维在空间上更为离散,由三维细观单元弹塑性损伤非线性反映宏观试样的非线性,更能深入地研究细观破坏机理;提出的破坏单元网格消去法为有限元清晰模拟裂纹开辟了新的途径;并行算法程序的实现为应用于大型三维水利水电工程奠定了基础。

Study Of Three-Point Bending Marble Beam Elastoplastic Damage

An elastoplastic damage constitutive model based on incremental theory is deduced in strain space.A mesoscopic numerical model to study the progressive failure process and the nonlinear mechanical behavior of heterogeneous rock is established in combination with an elastoplastic damage constitutive for rock mesoscopic element.The failure elements deleting method is used to simulate crack propagation in program.The calculation results achieved by numerical simulation and practical projects application agree well with those of in-situ tests,which illuminates that elastoplastic damage mesoscopic model could reflect local plastic characteristics of fractured rock masses.Three-dimension marble model is more reflect mesoscopic failure than two-dimension model.The failure element deleting method is good at showing explicitly crack propagation.It is proven that the numerical model is right and feasible.The failure elements deleting method solves the difficult problem of FEM to simulate the propagation.The model and method might be valid in practical projects.