The Investigation Of Dynamic Fracture Toughness For Compact Tension Specimen

Studying on the fracture performance has a very important meaning for the design of components and structural safety in engineering guidance.Because of the complexity in experimental method to solve the dynamic fracture problem,it is difficult to obtain dynamic fracture toughness.It means that investigation on the dynamic fracture toughness has become one of the hot issues in the research of the fracture theory.In this paper,compact tension specimens with prefabricated crack have been used both in static experiment and dynamic experiment.The fracture properties of LY12 cz aluminum alloy can be obtained.And improve the experiment methods simultaneously.Fracture toughness of different thickness of the specimen is calculated by finite element software.As a result,observing the crack phenomenon,and analyzing the influence of specimen thickness on fracture toughness.Major work includes several aspects:1.Using the method of fatigue test to process of prefabricated crack on compact tension specimens,in order to obtain the result of the static fracture toughness,first of all,there is a static tensile experiment.Secondly,by using the Hopkinson experimental apparatus to process dynamic tensile experiment,obtain the dynamic fracture toughness of this material.2.Based on the dynamic experiment model,using ABAQUS software and the extended finite element method to process simulation analysis on the whole dynamic experiment,observe distribution of stress both in device and in specimen which under the certain circumstances of dynamic experiment loading.3.The conventional finite element method provided by ABAQUS software was taken to calculate the dynamic J integral of compact tension specimens with different thickness.Judge the accuracy of calculation data by using experimental data.4.By analyzing the behaviors of different thickness of specimens crack extension and the J integral values,discuss on whether specimen thickness has a great effect on crack propagation and dynamic fracture toughness of materials.