10.11: Fire design of rectangular hollow section joints

Abstract

ABSTRACTThe component method is a design approach for the characterization of the mechanical properties of structural joints and it is referred to in Eurocode 3 Part 1‐8. Eurocode design rules for open sections are already based on the component method. The design rules for joints between tubular hollow sections are still based on simple theoretical mechanical models validated against experimental test results. However, there are research activities in progress to extend the application of the component method also to hollow section joints in the next revision of Eurocode. The fire design of steel joints is carried out in accordance with Eurocode 3 Part 2. Eurocode gives only a guidance on how the temperature of the joint components can be assessed based on the local values of thermal resistance of the joint's fire protection. The method is not sufficient for the component method and Tampere University of Technology is currently carrying out experimental fire research to better understand the temperature distributions in the vicinity of the joint. The aim of the research is to develop experimental methods to determine steel temperatures at the actual joint component, spring, locations and to transfer this information into the joint design approach based on the component method. This paper introduces an experimental research demonstrating the actual temperature distributions within the joint area and highlights the differences between the failure modes and the design criteria at normal temperature design and fire design of a joint.