Fundamental Study on Application-Phase Numerical Prediction Method for Dynamic Fracture Propagation Paths

本研究项目主要开展了以下几个方面的基础研究：（1）动态裂缝路径预测的应用相模拟方法学的开发;（2）动态分支裂缝路径预测方法学的开发。这些研究是通过统一使用实验、理论和计算力学方法进行的。通过这些研究，获得了有关动态断裂现象的基本信息和数据。此外，还阐明了动态断裂现象的一些机理。本课题的主要研究成果如下：1.实验研究：（1）阐明了动态分叉断裂的控制条件（2）发展了跨音速界面断裂的焦散线理论（3）发展了自动检测和消除实验测量误差的各种智能混合测量方法（4）发展了最小相关性 ...更多信息 全场测量图像相关法的系数搜索法（5）动态裂纹尖端能流与断裂表面粗糙度相关性的阐明（6）跨音速扩展裂纹尖端应力奇异场因子和奇异阶数的测量2.理论研究（1）动态界面断裂统一渐近解的推导（2）动态分支裂纹路径无关动态J积分切换方法的发展（3）压电材料动态J积分的推导（4）压电材料裂纹尖端渐近近场解的推导（5）机械混合裂纹的分量分离方法的发展（6）压电材料裂纹尖端渐近解的推导（7）压电材料裂纹尖端渐近近场解的推导（8）压电材料裂纹尖端渐近解的推导（9）压电材料裂纹尖端渐近解的推导（10）压电材料裂纹尖端渐近解的推导（11）压电材料裂纹尖端渐近解的推导（11）压电材料裂纹尖端渐近解的推导（12）压电材料裂纹尖端渐近解的推导（11）压电材料裂纹尖端渐近解的推导（12）压电材料裂纹尖端渐近解的推导（13）压电材料裂纹尖端渐近解的推导（14）压电材料裂纹尖端渐近解的推导（15）压电材料裂纹尖端渐近解的推导（16）压电材料裂纹尖端渐近解的推导（17）压电材料裂纹尖端渐近解的推导（18）压电材料裂纹尖端渐近模态应力强度因子和电位移强度因子。(6)卡拉克增长问题变分原理的推导3。计算力学研究：（1）基于Delaunay自动网格生成的各种移动有限元方法的发展（2）动态分支断裂的数值路径预测模拟的成功（3）恒定裂纹加速度下动态断裂现象的应用阶段模拟的成功（4）自然和动态扩展裂纹前缘的动态J积分和应力强度因子的评估（5）非线性动态断裂模拟方法的发展（6）跨音速界面断裂与裂纹面接触的模拟方法的发展（7）三个界面断裂的形成机理的阐明（8）三个界面断裂的形成机理的研究（10）非线性动态断裂模拟方法的发展（11）非线性动态断裂模拟方法的发展（12）非线性动态断裂模拟方法的发展（13）非线性动态断裂模拟方法的发展（14）非线性动态断裂模拟方法的发展（15）非线性动态断裂模拟方法的发展（16）非线性动态断裂模拟方法的发展（17）非线性动态断裂模拟方法的发展（18）非线性动态断裂模拟方法的发展（19）非线性动态断裂模拟方法的发展（19）非线性动态断裂模拟方法的发展（三维动态断裂前缘由于上述研究成果包含许多重要项目，本研究项目的成果可望对动态断裂力学的发展作出贡献。(1)JSME材料和力学成就奖，（2）JSME最佳论文奖，（3）JSME计算力学成就奖，（4）JSMS影响部门成就奖，（5）SEM Hetenyi奖减

In this research project, fundamental studies were carried out mainly for the following items : (1) development of application-phase simulation methodology for dynamic fracture path prediction, and (2) development of dynamic branching fracture path prediction methodology. These studies were performed by using experimental, theoretical and computational mechanics approaches in a unified fashion. Through these investigations, fundamental information and data on dynamic fracture phenomena were acquired. Furthermore, some mechanisms of dynamic fracture phenomena were clarified. The major research results of this project are listed as follows :1. Experimental Studies :(1) Elucidation of the governing condition for dynamic branching fracture(2) Development of the theory of caustics for transonic interfacial fracture(3) Developments of various intelligent hybrid measurement methods automatically detecting and eliminating experimental measurement erros(4) Development of the minimum correlation … More coefficient searching method for full-field measurement image correlation method(5) elucidation of correlation between the dynamic crack-tip energy flux and fracture surface coarseness(6) Measurements of the stress singularity field factor and the singularity order for transonically propagating crack tips2. Theoretical Studies(1) Derivation of a unified asymptotic solution for dynamic interfacial fracture(2) Development of the switching method of the path independent dynamic J integral for dynamically branched cracks(3) Derivation of the dynamic J integral for piezoelectric materials(4) Derivation of the asymptotic crack tip near field solution for piezoelectric materials(5) Development of the component separation method for extracting mechanical mixed-mode stress intensity factors and the electric displacement intensity factor.(6) Derivation of the variational principle for carack growth problems3. Computational Mechanics Studies :(1) Developments of various moving finite element methods based on Delaunay automatic mesh generation(2) Success of numerical path perediction simulations of dynamnic branching fracture(3) Success of the application-phase simulations of dynamic fracture phenomena under constant crack acceleration(4) Evaluation of the dynamic J integrals and the stress intensity factors for naturally and dynamically propagating crack fronts(5) Development of nonlinear dynamic fracture simulation methodology(6) Development of simulation methodology for transonic interfacial fracture with crack-face contact(7) Elucidation of the formation mechanism of three-dimensional dynamic fracture frontSince the above research results include many important items, the outcomes of this research project can be expected to contribute to the advancement of dynamic fracture mechanics.For the present and related achievements, the following awards have been offered.(1) JSME Materials and Mechanics Achievement Award,(2) The JSME Award for Best Paper,(3) JSME Computational Mechanics Achievement Award,(4) JSMS Impact Division Achievement Award,(5) SEM Hetenyi Award Less