Experimental study on structures with flaws under impact loading
YANG Ren-shu1,2, DING Chen-xi1, YANG Li-yun1, CHEN Cheng1, SUN Jin-chao1
1. School of Mechanics and Civil Engineering , China University of Mining and Technology, Beijing 100083,China;
2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Beijing 100083，China
Using the test system of digital laser dynamic caustics (DLDC) and experimental impacting platform of drop hammer, hole and crack flaws were brought into one experimental research system with single variable of curvature. Dynamic three point bending test of strip PMMA specimens with different flaws under impact loading was studied. Fracture failure experienced three stages: crack initiation and propagation at bottom border of specimens duo to impact stress wave during initial stage; stress release and crack stagnation at flaws during medium stage; crack initiation at top tips of flaws and running through specimens duo to the weight of drop hammer during ultimate stage. Under the same test condition, changes of curvature at flaw tips almost had no effect on crack initiation and propagation during initial stage; stagnation time became shorter with curvature increasing at flaw tips during medium stage, proximate functional relationship between the two was obtained; the stress intensity factors of crack initiation at flaw tips decreased first and then increased with the curvature increasing within limits during ultimate stage.
杨仁树1,2，丁晨曦1，杨立云1，陈程1，孙金超1. 含缺陷结构的冲击断裂试验研究[J]. 振动与冲击, 2016, 35(15): 103-108.
YANG Ren-shu1,2, DING Chen-xi1, YANG Li-yun1, CHEN Cheng1, SUN Jin-chao1. Experimental study on structures with flaws under impact loading. JOURNAL OF VIBRATION AND SHOCK, 2016, 35(15): 103-108.
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