3D-DDM Crack Tip Boundary Element Improvement In Shape And Numerical Simulation Principium

Having adopted the familiar numerical solution to solve the crack tip issue, but the result generally lead to higher error in evaluated, then solution to nearby crack tip is required. Fortunately, the basis solutions of the boundary element method take on attributive haracter of singularity, so, through fel- icitously element division, shape improvement and dealing with numerical integral ingenious in technique. And else, crack tip precision in calculation can be improved highly. Firstly, demonstrating the original constant element (flat board element) displacement discontinuity method to resolve stress intensity factors and stress field nearby crack tip is inefficient, its arises from the geometrical shape of element is inconsistent with geometrical shape of crack tip, and so on. Use for reference crouch's means to amend two dimensional crack tip, bring forward three dimensional parabolic crack tip element to improve original flat element. So such, both shape consistent with boundary element geometrical shape, and simulate crack tip close-by variety law of stress and strain with higher precision, and enhancing calculative efficiency. Deduce the influence coefficients of the amended parabolic crack tip element detailed, and provided the calculating equations and numerical calculational methods. Especially, by aid of analytical solution of two dimensional parabolic displacem- ent discontinuity methods to solve the self-influence coefficient,then avoiding of element self-integral directly, resolve the singular integral, enhance calcu- lative precision. Because of 3D-DDM is characteristic of solving the discon- tinuity displacement essentially, then adopting it on stress intensity factor close-by crack tip is convenient and directly, moreover, simulative pattern is reasonable and predominantly.In addition, dissertate the solution steps concretely for three dimensional displacement discontinuity methods, and analyze implementation principium to the three dimensional boundary element numerical simulative system.