加载方式及抗拉强度对巴西圆盘试验影响的连续-非连续方法数值模拟

发布时间：2018-02-26 19:19

本文关键词： 巴西圆盘开裂抗拉强度加载板巴西平台圆盘集中力连续-非连续方法数值模拟　出处：《岩土力学》2017年01期 　论文类型：期刊论文

【摘要】：研究了集中加载、加载板加载和平台加载3种不同加载方式对巴西圆盘的宏观力学行为、开裂过程以及材料的抗拉强度的影响。对于平台加载方式给出了不同平台加载角时抗拉强度的修正系数。在数值模拟中,采用了自主开发的连续-非连续方法,该方法将拉格朗日元、变形体离散元及虚拟裂纹模型耦合在一起,既可以很好地模拟弹性阶段的变形,又可以较好地模拟材料的真实开裂过程。研究发现,采用平台加载方式,有利于圆盘中心起裂,而采用集中加载和加载板加载方式,圆盘的加载部位容易发生剪破坏。在圆盘中心起裂时,集中加载方式的抗拉强度的数值解最接近于选取的抗拉强度,然后是加载板加载方式,最后是平台加载方式。无论对于哪种加载方式,在材料的抗拉强度较小时,圆盘易于中心起裂,否则圆盘的加载部位将发生剪破坏。圆盘中心起裂后,众多微裂纹汇聚成的裂纹带在垂直方向不断扩展,直至贯穿整个圆盘,同时伴有应力波产生并传播。
[Abstract]:The macroscopic mechanical behavior of Brazilian disc subjected to concentrated loading, loading plate loading and platform loading is studied. The influence of the cracking process and the tensile strength of the material on the loading mode of the platform is given. The modified coefficient of the tensile strength of the platform with different loading angles is given. In the numerical simulation, the self-developed continuous-discontinuous method is adopted. By coupling Lagrangian element, deformable discrete element and virtual crack model, the method can not only simulate the deformation of elastic stage but also simulate the real cracking process of material. It is advantageous to crack in the center of the disc, but the loading part of the disc is prone to shearing failure by means of the concentrated loading and the loading plate, and the numerical solution of the tensile strength of the concentrated loading mode is the closest to the selected tensile strength when the center of the disc begins to crack. Then there is the loading mode of the loading plate, and finally the loading mode of the platform. For any loading mode, the disc is prone to crack at the center when the tensile strength of the material is low, otherwise the loading part of the disc will be subjected to shearing failure. Many microcracks converge to form a crack band which propagates continuously in the vertical direction until it runs through the whole disc with the stress wave produced and propagated at the same time.
【作者单位】：辽宁工程技术大学力学与工程学院;辽宁工程技术大学计算力学研究所;辽宁工程技术大学安全科学与工程学院;
【基金】：国家自然科学基金项目(No.51374122) 辽宁省高等学校优秀人才支持计划(No.LR2015029) 辽宁省科学事业公益研究基金(No.2014003008) 高等学校博士点专项科研基金(No.20132121110006)联合资助~~
【分类号】：TU45

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