摘要
结合破坏力学和统计力学的思想 ,研究了基于损伤随机演化观点的混凝土本构关系和混凝土受拉损伤发展随机演化规律 .根据混凝土微细观材料破坏的声发射试验 ,确定了混凝土微单元破坏应变的随机分布特征 .通过对混凝土受拉试件细观物理机制的分析 ,揭示了混凝土轴心受拉应力 -应变关系中的应力跌落现象 ,并建立了跌落后的应力表达式 .
In the paper,a new stochastic constitutive model was proposed,which can demonstrate the rendom damage evolution law of concrete material under Uni-axial tension stress.Based on the Acoustics Emission character during the strain-stress history test,a traditional spring model was renewed to explain the damage mechanism.In the model,by establishing the relationship of the distribute character and AE energy emission rate ,the strain stochastic failure field(SSFF) is formed.So the course of damage development is simulated with the SSFF.Within the frame of energy equivalence law,the critical valve strain which began to be unstable and again to stable were concluded in mean level,so the macro strain-stress history curve was redisplayed by the failure mechanism model.The reason for brittleness for concrete material can also be explained by comparing the ideal representative element with the general element.In order to testify the validity of the model,the calculated result was compared with the test result.It shows that the model forecasted strength is quite near the test value.And the model can also forecast the scatters of concrete in probability means.
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2001年第10期1135-1141,共7页
Journal of Tongji University:Natural Science
基金
国家杰出青年科学基金资助项目 ( 5 982 0 10 5 )
关键词
混凝土
本构关系
随机演化
随机损伤
concrete
constitutive relationship
random evolution
random damage
