Finite Element Analysis of Stress Distribution in the Node Region of Isogrid Thin-Walled Panels

The paper presents numerical investigations of thin-walled integrally stiffened plates subjected to in-plane loading. Stiffening was in the form triangle grid called isogrid. Analytical solutions, on account of geometrical complexity of such structures, are mainly based on smeared stiffener and are limited only to preliminary design phase. To obtain more accurate results the application of FEM is required. The aim of the study was to determine the discretization strategy, type of used finite elements and its number on the accuracy of numerical results. Numerical representation of the considered structure was developed with the use of ABAQUS commercial FEM code. Each of the models was analyzed with taking into account both geometrical and physical nonlinearities. In particular, the focus was aimed at the analysis of the stress distribution in the area of the node of the grid. The conducted research allowed to compare numerical results among themselves and in relation to experimental investigations conducted with the use of the DIC scanner. The obtained results made it possible to formulate recommendations regarding possible simplifications of numerical modelling of the considered isogrid structures.