On the Enforcement of Essential Boundary Conditions in NURBS-based Isogeometric Analysis
An improved formulation for NURBS-based isogeometric analysis is presented. This is fulfilled by employing a transformation method that relates the control variables to the collocated nodal values at the essential boundary. By using open knot vectors, the resulting NURBS basis functions associated with the interior control points vanish at the boundary. Thus unlike the meshfree approximation, the NURBS control points can be clearly partitioned into boundary and interior groups. Therefore the transformation method can be only applied to the boundary control points via invoking collocation of physical values at a set of boundary points. The NURBS approximation enhanced with transformed physical boundary variables is kinematically admissible and the essential boundary conditions can be enforced straightforwardly like the finite element method. Several potential and elasticity problems evince that much higher solution accuracy with optimal convergence rates can be achieved by the present improved formulation compared with the method with direct imposition of essential boundary conditions to control variables.
NURBS, Isogeometric analysis, Essential boundary condition, Control variable, Transformation method, Meshfree method
Junchang Xuan Dongdong Wang Zhenting Lin
Department of Civil Engineering, Xiamen University, Xiamen 361005, China
国际会议
南京
英文
94-103
2009-10-12（万方平台首次上网日期，不代表论文的发表时间）