NUMERICAL SIMULATION OF CRACKED PLATE USING ISOGEOMETRIC ANALYSIS

Abstract

In the modern day to day applications in industries, ships, pressure vessels, and other structural components, plates and shells play a major role. Therefore, it is quite important to study the stresses generated within the body in order to understand the behavior and possible conditions of failure under various loading and boundary conditions. Plates when exposed to severe load conditions could develop high stresses with in the body which sometime exceeds the material strength and therefore result in the failure of the component. These failures generally start by surface or near the surface cracks. Presence of these cracks in plates reduces their strength. The presence of flaws like cracks might lead to sudden failure which results in the heavy loss of money and lives of workers. Therefore, it is important to evaluate the stress distribution in the region near the crack in order to predict the failure. To accurately predict the failure of component, stress intensity factor (SIF) needs to be computed accurately. So, the plates with various types of discontinuities are analyzed under different loading boundary conditions. It is difficult to model and simulate plate with discontinuities by standard FEM because of the need of mesh adaptation and remeshing to model growing crack. FEM become computationally costly and does not give accurate results for this type of problems. So, extended finite element method (XFEM) can be effectively used to solve these problems. To further increase the accuracy and reduce the time of computation, extended isogeometric analysis (XIGA) is used, which is quite good technique to model and simulate the problems with complex geometries .Geometries in XIGA are modelled accurately unlike FFM/XFEM as same basis functions are used to model and simulate the problem in XIGA. In this dissertation report, the simulation of plate bending problems is performed in the presence of various types of discontinuities under different combinations of boundary and loading conditions. The numerical simulations have been performed by XIGA and XFEM. The simulation shows that the results obtained by XIGA are found more accurate than XFEM results.