摘要
基于Split-Hopkinson Pressure Bar(SHPB)实验原理和硬脆材料自身特性,对传统SHPB实验进行改进,开展氧化锆陶瓷动态力学性能研究。研究表明,随着冲击气压的上升,氧化锆陶瓷断口趋于复杂,碎块尺寸分布不均匀,且具有尖锐棱角。氧化锆陶瓷破坏应变极小,约为0.01,其破坏是由于材料内部的起裂、裂纹扩展和连续累积达到一定阶段时产生宏观裂纹所致。在中高应变率下,氧化锆陶瓷为应变率敏感材料,其初始弹性模量、破坏应力与应变率呈正相关。基于损伤力学理论,将弹性模量的退化定义为损伤变量并结合弹脆性损伤模型,建立了一维冲击载荷下氧化锆陶瓷的弹脆性损伤本构模型。利用SHPB实验数据对本构模型进行拟合,确定了氧化锆陶瓷材料弹脆性损伤本构关系,较好地解释了氧化锆陶瓷受一维冲击载荷时应力应变曲线呈现的非线性现象。
Considering the experimental principle and the characteristics of hard and brittle materials,the dynamic mechanical properties of zirconia were studied by using the improved SHPB experiment method.The results show that,with the rising of impact pressure,the fracture of zirconia tends to be complex,the fragment size is unevenly distributed,and sharp angularities arise.The zirconia ceramic has a very small strain at break of about 0.01,and the damage is caused by the macro crack generated when the initiation,expansion and continuous accumulation of the main cracks in the material reach a certain stage.At medium and high strain rates,zirconia ceramics are strain rate sensitive materials,whose initial elastic modulus,failure stress and strain rate are positively correlated.Based on the theory of damage mechanics,the elastic-brittle damage constitutive model of zirconia ceramics under one-dimensional impact load was established by defining the degradation of elastic modulus as the damage variable and combining the elastic brittleness damage model.By fitting the constitutive model with experimental data,the elastic-brittle damage constitutive relationship of zirconia ceramic was determined,by which the non-linear phenomenon of stress-strain curve of zirconia ceramic under one-dimensional impact load was explained.
作者
万林林
邓泽辉
邓朝晖
李乐
WAN Linlin;DENG Zehui;DENG Zhaohui;LI Le(Intelligent Manufacturing Institute of Hunan University of Science Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of High Efficiency and Precision Machining of Difficult-to-Cut Material,Hunan University of Science Technology,Xiangtan 411201,China)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2020年第5期785-790,784,共7页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(51405152)
湖南省自然科学基金资助项目(2017JJ2092)。
关键词
SHPB
氧化锆陶瓷
动态力学性能
本构模型
SHPB
Zirconia ceramics
Dynamic mechanical properties
Constitutive mode
