Analysis Of Aluminium Alloy Mesostructure Response Based On Homogenization Method And Crack Propagation

Aluminum and its alloys, which are lightweight and have great high-temperature performance, plastic properties, corrosion resistance and so on, are widely used in all walks of life, such as:aerospace, vehicle and construction industries,etc.7XXX alloys of aluminum alloys have higher strength, better toughness and corrosion resistance.7055aluminum alloy is comparatively outstanding representative of7XXX alloys and has bright application prospect. However, it is inevitable that the materials and structures had some defects. There were many common phenomena that when the materials and structures were bearing low stress, the defects led to their failure and fracture. Therefore, research about the responses of7055high strength aluminum alloy mesoscopic defect structure with loading and the crack propagation of7055mesoscopic defects structure with loading has important significance.In this paper, two projects including the responses of the mesoscopic structure and the crack propagation on aluminum alloy defects are researched. On the one hand, based on homogenization method the responses of aluminum alloy mesoscopic defect structure within a certain area under loading are analysed. Aluminum alloy mesoscopic defect structure model is established firstly. Then, the homogenization method is used to calculate the stress and strain of the whole mesoscopic structure and some curves are made to describe the stress and strain. The curves represent the mesostructure responses. The results indicate that in the initial stage of the structural deformation the stress distribution appears stress concentration in a banding area, and with the increase of the structural deformation the stress concentration becomes more and more serious; Later stage overall strain continues to increase, and the stress is falling. At different temperatures the homogenized stress and strain of the defect mesostructure are calculated and their curves are made. After the comparison of the different temperatures curves the reasons of the stress and strain changes are analysed. Under different loading rates the homogenized stress and strain of the defect meso structure are calculated and their curves are taken. And the reasons of the stress and strain changes are analysed by means of the comparison of the different loading rates curves.On the other hand, the material defects exist in a certain area and under loading the defects will be connected to produce a crack. In a finite element analysis platform, ABAQUS, the mesoscale multiple defects model of aluminum alloy within a certain area is established. Then in the area the connection of the defects is simulated to take a crack generation. The changes of the area stress and strain in the crack propagation process are analysed. Under different temperatures the crack propagation processes are simulated. By means of the comparison of the processes, the influence of temperature on the crack propagation processes is researched.