Simplified quadrilateral grid generation of complex free-form gridshells by surface fitting

Abstract

In this paper, a quadrilateral grid generation algorithm based on surface fitting is proposed for complex free-form surfaces. The ray-surface intersection and plane-surfce intersection methods are proposed to fit complex free-form surfaces into one free-form surface. Based on the fitted surface, quadrilateral grids were generated by using the geodesics or the Chebyshev algorithm. The grids were then smoothed by a physics-based algorithm. The grid quality was evaluated by fluency, shape quality and rod length indices. Compared with the conventional method in which grids are separately generated and manually modified, the fluency index and the standard deviation of the rod length index of the grids generated by the proposed methods reduce by up to 87% and 94% respectively. The results show that the grids generated by the proposed methods are more fluent and uniform compared with those by the conventional method.