【作者】 李英雷； 胡时胜； 李英华；

【Author】 LI Ying-lei~(1,2*),HU Shi-sheng~2,LI Ying-hua~1 (1.Laboratory for Shock Wave and Detonation Physics Research,Institute of Fluid Physics, China Academy of Engineering Physics,Mianyang 621900,Sichuan,China; 2.Key Laboratory of Mechanical Behavior and Design of Materials, University cf Science and Technology cf China,Chinese Academy of Sciences,Hefei 230027,Anhui,China)

【机构】 中国工程物理研究院流体物理研究所冲击波物理与爆轰物理实验室； 中国科学院中国科学技术大学材料力学行为和设计重点实验室；

【摘要】 为了得到陶瓷材料有效的实验结果,必须采川多种改进措施(Pulse Shaper、高强度和高刚度垫块、直接测试试样应变以及使用较大长径比的试样)来满足SHPB装置所要求的基本假设条件。研究以A95陶瓷的测试为例,通过数值模拟分析证明:针对陶瓷材料改进的SHPB装置,可以得到陶瓷材料的有效压缩应力-应变曲线和压缩破坏强度。但是在分析材料的压缩破坏强度时,必须排除劈开破坏的干扰。数值模拟研究发现,压缩测试中出现的劈开破坏是由卸载过程中出现的局部横向(沿直径)拉伸造成的拉伸破坏。在修正了弥散对压缩破坏强度的影响后,研究得到了A95陶瓷的压缩破坏强度为3.5GPa。A95陶瓷的高应变率压缩应力-应变曲线显示了良好的线弹性,并且曲线的斜率与杨氏模量相同。更多还原

【Abstract】 The characteristics of ceramics-high strength,high Young’ s Modulus and brittleness challenge the validity of basic assumptions for the SHPB experiments.One-dimension elasticity stress state and uniform axial stress in the specimen.Some modifications on the test configuration have been done such as pulse shaper,high strength pads,direct measurement of the specimen strain and so on.This research shows that a valid compression stress-strain curve and compression strength of A95 ceramic can be obtained with the modified SHPB technique,which is verified by the numerical simulation of the test.A95 ceramic shows a good linear elastic stress-strain curve.The split failure of A95 ceramic would be caused by the localized tension during unloading according to the numerical simulation.Therefore,the compression stregth measurements are not valid for the splited specimens.After related correction of dispersion in the failure strength data under compression,the failure strength of A95 ceramic is determined as 3.5GPa.更多还原