基于离散单元法的环氧沥青混凝土虚拟断裂试验研究

发布时间：2019-07-30 20:21

【摘要】：为明晰环氧沥青混凝土的断裂力学行为特征,基于数字图像处理技术,采用离散元方法建立了切口小梁二维模型,开展了环氧沥青混凝土的虚拟弯曲断裂试验.从细观角度分析了环氧沥青混凝土断裂过程中的力学响应,探讨了其断裂机理及裂纹扩展路径,并与室内试验结果进行了对比.结果表明,采用离散元方法可较好地反映环氧沥青混凝土的断裂力学特性,数值模拟过程中虚拟试件的力学响应与理论结果相符.虚拟试验获取的材料强度参数与室内试验的测试结果接近,误差仅为0.25%,但前者所得的劲度模量因破坏挠度偏大,较后者低16.56%.在裂纹扩展过程中,破坏易产生于黏结较为薄弱的集料-砂浆界面.虚拟试验与室内试验的对比分析结果验证了离散元模型以及参数取值的正确性.
[Abstract]:In order to clarify the fracture mechanical behavior characteristics of epoxy asphalt concrete, based on digital image processing technology, a two-dimensional model of notch trabecula was established by using discrete element method, and the virtual bending fracture test of epoxy asphalt concrete was carried out. The mechanical response of epoxy asphalt concrete during fracture is analyzed from a microcosmic point of view. The fracture mechanism and crack propagation path are discussed and compared with the laboratory test results. The results show that the discrete element method can well reflect the fracture mechanical properties of epoxy asphalt concrete, and the mechanical response of the virtual specimen in the process of numerical simulation is in good agreement with the theoretical results. The strength parameters obtained by virtual test are close to those obtained by laboratory test, and the error is only 0.25%. However, the stiffness modulus of the former is 16.56% lower than that of the latter because of the large failure deflection. In the process of crack propagation, the failure is easy to occur at the interface between aggregate and mortar with weak bonding. The comparative analysis results of virtual test and laboratory test verify the correctness of discrete element model and parameter value.
【作者单位】：长安大学公路学院;江西省桥梁检(监)测及加固重点实验室;东南大学教育部智能运输系统工程研究中心;
【基金】：国家自然科学基金资助项目(51178114) 江西省交通运输厅科技资助项目(2010C00005)
【分类号】：U414

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