Estudo do teste de esfera: determinação da isotropia de chapas metálicas

Abstract

This work aims the generalization of the Bali Test towards its application to every thickness of disk blades or metal plates on a predetermined internai energy levei. The standard procedure is given by NBR 9113/85. A lack of systematic studies of the relationship between the main variables of the test leads to restrictions on its application. This work first re-views mechanical anisotropy-concepts related to the subject and discusses the test variables and adimensional terras. Then, the stress distribution inner several geometries of plates is obtained by using the esperimental technique of Photoelasticity and a numerical Computer simulation based on the Finite Element Method. A failure theory founded on internai distortion energy is employed, criticai points being defined by maximum distor­tion energy leveis. The results are a formulation of test geo­metries which enable the performance of tests accordingly to the purpouses stated above, by means of the prediction equation developed. Practical data from initial stages of the developed formulae application on disk blades are also available.