【作者】 张志平；

【导师】 佟福山；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计与制造， 2003， 硕士

【摘要】 本文利用弹性力学中的应变能定理和裂纹圆模型的概念对裂纹扩展的能量机理作了新的剖析和简化，提出了裂纹扩展动力及其长度度量——裂纹扩展动力位移和角度度量——裂纹扩展动力角的解析模型和物理意义。借助裂纹圆模型简明地论述了Ⅰ型裂纹扩展的能量判据与应力强度因子判据的一致性以及线性断裂临界应力的新算法。 本文论述了断裂力学中的切线模量理论的基本框架，提出了求解非线性断裂临界应力的新方法——切线模量因子算法，并对该方法同现有的COD法作了理论上和计算上的比较。利用切线模量因子算法的PL(C，E)模型和COD法经验算式的关系，在理论上证明了COD法的局限性，同时说明了切线模量因子算法的PL(c，m)模型具有理论清晰、运用简便、求解精度高的优点。更多还原

【Abstract】 This thesis presents a new analysis and simplification to the energy principle of crack propagation by using the concept of crack-circle and strain energy principle in elastic mechanics. The analytic models of crack propagation motivity and its length measurement and angle measurement, the displacement of crack propagation motivity and the angle of crack propagation motivity, are builded. The consistency of the energy criterion and the stress intensity factor criterion to Model I crack is discussed concisely, and the new method to calculate linear critical fracture stress is presented.The basic frame of the theory of tangent modulus in fracture mechanics is builded, and the new method of tangent modulus factor to calculate nonlinear critical fracture stress is presented. The limitation of COD approach is proved in theory by using the relationship of the PL(C, E) Model of the method of tangent modulus and the COD experience formula. At the same time, this thesis shows that the PL(c, m) Model of the method of tangent modulus factor is clear, convenient and more exactitude by comparing with present COD approach.更多还原