Abstract:
"EFFECT OF MESH QUALITY IN FINITE ELEMENT ANALYSIS OF CRACK-TIP STRESSES IN A CIRCUMFERENTIAL SURFACE CRACK OF A PIPE ELBOW WELDMENT"
Errors and uncertainty in finite element method (FEM)-based simulations originate from numerous sources. In this paper, we will address the errors and uncertainties due to two sources, namely, the mesh density, and the mesh quality. Our approach, using a super-parametric method, is to design a family of meshes of increasing degrees of freedom for a specific element type and a number of mean aspect ratios representing different mesh quality, and solve them in order to estimate the most probably accurate solution and its uncertainty of the FEM-based simulations. To obtain an estimate of the "correct" solution at "almost" infinite degrees of freedom, we introduce a nonlinear least squares fit algorithm based on a 4-parameter logistic distribution and apply to a sequence of at least five candidate solutions for a specific platform, element type, and mean aspect ratio.
