A meshfree method based on weak-strong form for structural analysis

In this work, we propose a novel method associating a weak form Moving Least Square (MLS) method, also called Element Free Galerkin (EFG) method, and a strong form MLS method to solve the structural problems in two-dimensional elasticity. Therefore we use the displacement compatibility and the force equilibrium conditions on the interface to ensure the coupling between meshfree weak form method and meshfree strong form method. The strong form MLS method is easy to implement and computationally efficient, but it can be unstable and less precise for problems with Neumann boundary conditions. On the other hand, the weak form MLS method ensures very good stability and excellent precision, but it requires the numerical integration which makes this method not "truly" meshless and computationally expensive. Among of the advantages of the proposed method are the following: (i) numerical integrations are avoided for all nodes in the domain of the strong form approximation, (ii) the weak form can be used for nodes on the Neumann boundary, (iii) the strong form can be used in the region of large deformation. Comparative studies with analytical solutions and weak form methods are presented to show the effectiveness and performance of the proposed method.