为了拓宽结构弹塑性断裂的研究思路,丰富其研究方法,在研究切线模量理论的基础上,通过参数切线模量因子和断裂韧度的比较分析,得到基于线弹性断裂的弹塑性断裂临界应力计算方法。将衍生比例定律引入对裂纹尖端位移的线弹性断裂模型和大范围屈服模型的分析研究,可以建立求解非线性断裂应力的切线模量因子法。试验数据表明,该方法与COD方法具有等效的功能,且应用范围更为广泛。分析结果还表明,从材料的本构关系出发,通过改进表达的应变关系式可以推导出J积分的切线模量因子表达式,为求取J积分值提供新思路。
Based on tangent modulus theory and Derived Proportional Law (DPL), elastic-plastic fracture is analyzed. Through a comparison of parameters between tangent modulus factor and fracture toughness, a new method for calculating elastic-plastic critical stress fracture is established. The Experimental datum identifies that this method has the equivalent accuracy with COD method and has wider range of applications. The results also show that from the stress-strain relationship and improved strain relationship, aJ-integral expression can be obtained. It provides a new way to calculate the value of theJ-integral.