A numerical strategy for finite element analysis of no-tension materials

We present an algorithmic procedure for the finite element solution of structural problems for no-tension materials. The approach is based upon a suitable modification of the tangent strategy which is shown to be computationally superior to conventional procedures for non-linear material models, namely the tangent strategy enhanced with line searches and the tangent-secant approach. The solution of the constitutive problem for no-tension materials is derived by an original path of reasoning and its formulation in a strain-driven format, directly amenable to a computer implementation, is presented. For completeness the existing expressions of the tangent and secant operators for the no-tension model are briefly recalled and an original formula for the secant operator derived. The robustness of the proposed strategy is exemplified by the numerical results obtained for a masonry panel with openings. Remarkably, the solution is achieved by assigning a single load step and an asymptotically quadratic convergence rate is attained. Further, the numerical properties of the proposed solution strategy are practically unaffected by the adopted discretization.