Influence of the void-crack offset method on the dynamic behavior of PMMA during impact fracture#br#
YANG Renshu1,2，CHEN Cheng1，ZHAO Yong1，DING Chenxi1，SU Hong1，ZHENG Changda1
1.School of Mechanics & Civil Engineering, China University of Mining & Technology, Beijing 100083, China;
2.State Key Laboratory for Geomechanics & Deep Underground Engineering, China University of Mining & Technology, Beijing 100083, China
In order to study the influence of the void-crack offset method on the impact-fracture behavior of materials, PMMA was used as the experimental material.The dynamic caustic experiment method was used to study the three-point bending of impact loading.The results show that: under the impact load, the relative offset position of the hole and the prefabricated crack affects the crack initiation direction and the crack and void penetration.In the case of prefabricated crack offsetting, at the time of crack initiation, KdⅡ<0 and the direction of the fracture points to the empty hole; the hole has an attractive effect on the running crack, crack propagation path is parabolic, crack and hole coalesce, the crack will be initial again at the top of the hole.Under the condition of hole offsetting, KdⅡ>0 and crack initiation direction away from the hole; the role of hole on the propagating crack is attractive firstly, then repulsive and attractive finally, crack propagation path is S-type, crack and hole are not through.When the running crack and the empty hole penetrate, crack arrest will delay the destruction of the specimen on a time scale.But after the second crack initiation at the upper boundary of the hole, crack propagation velocity and dynamic stress intensity factor are increased accordingly, which will exacerbate the destruction of the specimen.
杨仁树1,2，陈程1，赵勇1，丁晨曦1，苏洪1，郑昌达1. 空孔-裂纹偏置方式对PMMA冲击断裂动态行为的影响[J]. 振动与冲击, 2018, 37(20): 122-128.
YANG Renshu1,2，CHEN Cheng1，ZHAO Yong1，DING Chenxi1，SU Hong1，ZHENG Changda1. Influence of the void-crack offset method on the dynamic behavior of PMMA during impact fracture#br#. JOURNAL OF VIBRATION AND SHOCK, 2018, 37(20): 122-128.
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