Verificação da segurança de ligações parafusadas em chapas metálicas segundo a NBR 8800:2008

Abstract

It is important to know how the peculiarities of the connections in metallic structures to these can be at risk of durability and structural safety in case of failure in the design. In this way, this work aims to check compliance safety screwed on metal sheets subjected to tensile stress in order to continue with the effects: a) shearing of the screws; b) traction in the plate; c) Pressure of support and tear of the plate; d) Block shearing. Through the requirements of the NBR 8800 were rated five different types of connection, for the subsequent realization of tensile testing in order to determine the maximum load, in fact, each link can support and compare the expected result. The initial sizing of the connections take into account the thickness of the plates, the diameter, quantity and spacing of the bolts made for ASTM A36 steel plates and ASTM A325 bolts. Due to the acquisition of material with a specification different from what was requested and confirmed by the supplier, results were obtained only for 40% of the predicted tests. In this way, two different designs were made, one for ASTM A572 gr50 steel and another for ASTM A36 steel. All the tests in which rupture is obtained (for both types of steel) approximately 60% of the tests performed showed the type of rupture desired, with variations in the load of rupture with respect to the predicted load.