On the evaluation of the method of finite spheres for the solution of Reissner-Mindlin plate problems using the numerical inf-sup test

In this paper we use the numerical inf-sup test to evaluate both displacement-based and mixed discretization schemes for the solution of Reissner-Mindlin plate problems using the meshfree method of finite spheres. While an analytical proof of whether a discretization scheme passes the inf-sup condition is most desirable, such a proof is usually out of reach due to the complexity of the meshfree approximation spaces involved. The numerical inf-sup test (Int. J. Numer Meth. Engng 4997; 40:3639-3663), developed to test finite element discretization spaces, has therefore been adopted in this paper. Tests have been performed for both regular and irregular nodal configurations. While, like linear finite elements, pure displacement-based approximation spaces with linear consistency do not pass the inf-sup test and exhibit shear locking, quadratic discretizations, unlike quadratic finite elements, pass the test. Pure displacement-based and mixed approximation spaces that pass the numerical inf-sup test exhibit optimal or near optimal convergence behaviour. Copyright (c) 2007 John Wiley & Sons, Ltd.