Fracture criticality based on free surface deformation measurement
Free surface deformation can be accurately measured in many cases,especially with the wide application of various sensors.Can the free surface measurements be directly used to evaluate the fracturing possibility? If the free surface deformation fracture criticality can be established,the answer will be certain.However,in fracture mechanics,the fracture criticality is formulated by three principle stress components.So,the answer seems to be negative.In this research,the related theoretic problems are studied.The fracture criticality for free surface deformation is established based on general fracture criticality.The main points of this formulation are that the free surface stress fields are determined by the medium deformation as a whole,rather than the conventional zero stress condition on free surface.The physical acceptable description about the free surface is volume invariant deformation with surface stretching.So,the free surface deformation is described by the local relative rotation followed by a surface stretching.Based on the measurement of rotation direction,rotation angular and length variations,the free surface stress field is constructed.Then the fracture criticality based on free surface deformation measurements is formulated.
Rotation angular Local rotation Free surface deformation Fracture criticality Fracture mechanics Rational mechanics
Jianhua Xiao Zhengchang Guo
Henan Polytechnic University,Measurement Institute,Jiaozuo 454000,China
国际会议
成都
英文
145-149
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）