动载下韧性撕裂在三种管线钢材中传播阻力的研究

阐述了用实验确定在常温及静载和动载条件下韧性撕裂在三种管线钢材中传播时的断裂比能值。实验中采用了销钉加载双面开槽的双悬脊梁(DCB)试件。应用能量平衡法对实验结果进行了分析。考察了加载速率和试件厚度对撕裂韧性的影响。结果表明,管线钢材对韧性撕裂传播的阻力在动载条件下增大,对较薄的试件及应变率敏感性较高的材料其增大更为明显。对于纯剪切断裂的传播来说,撕裂韧性一般随试件厚度的增大而增加。

EXPERIMENTAL INVESTIGATION ON MATERIAL RESISTANCE AGAINST DUCTILE TEARING GRACK PROPAGATION DURING DYNAMIC LOADING ON THREE KINDS OF PIPELINE STEEL

The specific fracture energy for ductile tearing crack propagation in three kinds of pipeline steel was experimentally determined at room temperature under quasi-static and dynamic loading conditions using pin-loaded side-grooved double cantilever beam (DCB) specimens. The test results were analysed using energy balance method. The effects of loading rate and specimen net thickness on tearing toughness were investigated. It is found that the material resistance of pipeline steel against ductile tearing crack propagation in dynamic case is larger than that in quasi-static case., especially for thin specimens and for steel with high strain rate sensitivity. Tearing toughness generally increases with the increase of specimen net thickness for pure shear fracfure propagation.