Research on performance of high-strength bolted connection in fire and after fire

Abstract

Experiments on the tensile performance and the shear performance in high temperature and shear performance after fire have been carried out to study the fire-resistant performance of high-strength bolted connection. The experimental research on the shear performance of the connection in high temperature reveals the effect of temperature on the mechanical performance of high-strength bolted steel. A formula for the mechanical performance index can be obtained through a comparative analysis. The research on the shear performance of high-strength bolt in high temperature presents the effect of temperature on the bolt's sliding load and limit load. The formula for calculating the sliding load and limit load for shear connection at high temperature can be put forward through a comparative analysis on the basis of the test results. The test results for the shear property of post-firing high-strength bolted connection reveal the change law of the sliding load in different fire temperatures, fire processing methods and types of cooling. Moreover, the calculation formula of the reduction coefficient of the sliding load is given. Research findings provide theoretical basis for research on fire-resistant performance of steel structure joints and the prerequisite for overall fire-resistant design of steel structures and act as an important reference for compiling and revising relevant codes. This paper can promote the improvement and development of fire-resistant design methods of steel structures.