Smooth Boundary Based Optimisation Using Fixed Grid
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چکیده
1. Abstract This paper presents a boundary based structural optimisation in the finite element fixed grid environment. The boundary is represented by smooth B-spline curves, as they typically require a relatively small number of control points to describe a curve. Utilising B-spline control points reduces the number of design variables whilst achieving a smooth boundary representation. An appropriate control point coordinate modification formulation with addition/removal of control points, derived from the optimality criteria of compliance based optimisation, is introduced in the paper. The paper also examines a range of structural analysis solvers appropriate for frequent boundary modifications in topology optimisation. Previous studies have found that iterative pre-conditioned conjugate gradient solvers with appropriate pre-conditioners were most efficient for analysis and reanalysis. Whilst it has been shown that LU decomposition of the stiffness matrix can offer a fast convergence for reanalysis, it cannot guarantee convergence. The performance of the pre-conditioned conjugate gradient solver for optimisation is carefully studied with some of the latest direct solvers developed for elasticity and FE problems. The careful implementation of the analysis solver together with the reduced number of design variables achieves an efficient and structural optimisation scheme. This is demonstrated in the paper numerically via simple shape optimisation problems, followed by preliminary results for topology optimisation.
منابع مشابه
Bath Institute For Complex Systems Preprint 1 / 07 ( 2007 ) Smooth Boundary Based Optimisation Using Fixed Grid Caroline
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تاریخ انتشار 2007