基于CLoE亚塑性模型的密砂循环荷载下力学行为模拟

发布时间：2018-11-09 15:27

【摘要】：亚塑性模型为模拟颗粒材料的非线性力学行为提供了一条新途径,特别是CLoE亚塑性模型在模拟应变局部化时具有一定的优势。然而该模型在模拟小幅应力-应变循环时表现出一定的锯齿效应。为了克服该效应,基于颗粒间应变张量的概念发展了修正的CLoE亚塑性模型以正确模拟循环荷载下密砂的力学行为。此外,为保证单调荷载作用下修正模型与原模型预测结果的一致性,改进了颗粒间应变率及颗粒间最大应变的定义。数值算例表明:(1)修正模型保留了克服锯齿效应的优点。(2)修正模型能够反映不同振幅条件下的卸载刚度。(3)在大振幅循环条件下,滞回圈的面积随着循环次数增加而增大。(4)修正模型能够保证单调加载条件下所得结果与原模型的一致性。(5)修正模型可以反映材料的疲劳破坏机制。
[Abstract]:The hypoplastic model provides a new way to simulate the nonlinear mechanical behavior of granular materials, especially the CLoE model has some advantages in simulating strain localization. However, the model shows a sawtooth effect in simulating small stress-strain cycles. In order to overcome this effect, a modified CLoE subplastic model was developed based on the concept of inter-particle strain Zhang Liang to correctly simulate the mechanical behavior of dense sand under cyclic loading. In addition, in order to ensure the consistency of the prediction results between the modified model and the original model under monotone load, the definitions of inter-particle strain rate and maximum inter-particle strain are improved. Numerical examples show that: (1) the modified model retains the advantages of overcoming the sawtooth effect; (2) the modified model can reflect the unloading stiffness under different amplitude conditions; (3) under the condition of large amplitude cycle, The area of hysteresis loop increases with the increase of cycle times. (4) the modified model can ensure the consistency between the results under monotone loading and the original model. (5) the modified model can reflect the fatigue failure mechanism of materials.
【作者单位】：武汉大学土木建筑工程学院;
【基金】：国家自然科学基金项目(No.10802060,No.11172216) 国家重点基础研究发展计划(No.2010CB731502)
【分类号】：TU441

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