Study On Stress Singularities Of Three-Dimensional Interface Edge Under Impact Load

With the development of technology, combined material regarded as a kind of new materials had been widely used in various fields of engineering. Structures were subjected to impact load in engineering application. However, because of the different properties between two materials at both sides of the interface, it would produce stress singularity in interface edge region. Thus, the research of stress singularity of interface edge under impact load was of great significance. This paper was the study of the interface problems in the range of elasticity under impact load.Firstly, based on the basic theory of two-dimensional interface, numerical simulation of three-dimensional interface model was made under impact load. It analyzed the velocity-responses and acceleration-responses of three-dimensional interface structures. The discontinuity of stress at both sides of the interface was validated. It indicated that stress wave would be retardant and strain energy would be accumulating by interface.Secondly, we used the three-dimensional interface model with double singularity under static load and impact load. The displacement results which nearby the interface edge area was obtained and singularities number of interface edge was separated and obtained by applying these double singularity displacement fields. And then we got a simple and effective method of calculating eigenvalue of double stress singularities. By comparing with singularities number of interface edge under static load and impact load, we drew a conclusion that eigenvalue of stress singularities was concerned with combinative forms of interface and material constants.At last, by using isotropic material, interface bonding angle, modulus of elasticity and different matching combination effect on stress singularity of three-dimensional interface edge were discussed under impact load. By comparing the numerical results, we concluded that stress singularity of interface edge enhanced with accretion of interface bonding angle or elastic modulus ratio. Local acute angle design of interfacial angle and the diminution of material elastic modulus on both sides of the interface were conducive to decrease stress singularity of the interface edge. It would obviously improve carrying capacity of the whole structure. By comparing with two different matching groups, we could know that singularity would be weaken or disappeared at interface edge of weak stress singularity combination. At the same time, discriminant conditions of three-dimensional stress singularity were validated under different matching combination.