Stress Concentration Analysis in Orthotropic Plates

Lucas Lisbôa Vignoli¹; Jaime Tupiassú Pinho de Castro¹; Marco Antonio Meggiolaro¹

¹ Pontifical Catholic University of Rio de Janeiro

doi:10.20906/CPS/COB-2015-0905

Resumo

Anisotropic materials are widely used for different industrial applications. An important class of anisotropic materials is the orthotropic one. Nine constants are necessary to characterize the elastic response of general orthotropic materials to mechanical loads, but thin composite plates can be approximately described using the plane stress assumption, which requires only four material constants. Even though the plane stress hypothesis seems to be quite restrictive, it can be used to model structures made of plate-like components, which are very common in practice. However, since most such components must have holes, slots, grooves, shoulders, corners, reinforcements, or similar abrupt geometric transitions generically called notches, the stress concentration problem in orthotropic plates has a major practical importance. This paper uses theoretical and numerical approaches to study stress concentration effects in orthotropic plates submitted to tension loads with an elliptical or circular hole. The theoretical part is developed using the well established Stroh formalism for infinite plates. The numerical part is implemented and solved using the Ansys commercial finite element package. The focus of the FE analysis is to evaluate the stress distribution along the hole border for finite plates. The results are compared to well known similar analysis for isotropic materials for both finite and infinite plates, as well as to some approximate methods to estimate stress concentration effects for finite orthotropic plates.

Palavras-chave: stress concentration; orthotropic plates