【作者】 刘争； 孙少南； 王昕； 陈旭；

【Author】 Liu Zheng;Sun Shaonan;Wang Xin;Chen Xu;School of Chemical Engineering and Technology,Tianjin University;

【机构】 天津大学化工学院；

【摘要】 紧凑拉伸试样是最常用的系统分析约束效应对断裂韧性影响的试样之一,在此文章中,对三维紧凑拉伸试样进行广泛的线弹性和弹塑性分析,考虑大范围变化的裂纹深度和试样厚度,得到J,应力强度因子（K）和面内、面外T应力(T₁₁、T₃₃)。结果表明:裂纹深度和试样厚度对T₁₁的影响很大,同时T33作为衡量面外约束效应参数不仅受到试样厚度的影响,也受到裂纹深度的影响;断裂韧性J随着T₁₁的增大而增大,随着T₃₃增大而减小。基于以上分析,用T₁₁和T33修正断裂韧性J,这些结果对包含面内、面外约束效应的结构完整性分析具有重要意义。更多还原

【Abstract】 In The present paper,extensive linear elastic and elastic-plastic Three-dimensional finite element analyses are conducted for compact Tension（CT）specimens,which is one of The most widely used specimen for The systematic investigation of The influence of constraint effects on the fracture toughness.Complete solutions of J,stress intensity factor（K）,in-plane and out-of-plane t-stresses(T₁₁ and T33)are obtained.A wide range of geometrical parameters variations are considered including in-plane crack depth to width ratio（a/W）and out-of-plane thickness to width ratio（B/W）.the results show that t₁₁ at the specimen mid-plane are affected by crack length and specimen thickness,meanwhile,crack length and specimen thickness have a significant impact on t33.In addition,it is observed that J is a monotonously increasing function of T₁₁ for all crack depth,and decrease linearly with the increase in T33.Based on the present finite element calculations for J,in-plane and out-of-plane T-stresses,empirical expressions for the in-plane and out-of-plane T-stresses effects on the fracture toughness are proposed.Solutions obtained will be very useful for structural integrity assessments by the failure assessment diagram（FAD）methodology,which incorporates both in-plane and out-of-plane constraint effects.更多还原