Experimental Study For The Performance Of Friction High Strength Bolt Connection Nodes In High Temperature Environment

The strength bolted connection is one way of connection which are widely used in the steel construction, and friction high-strength bolt connection is one way of the strength bolted connection. The researches of friction high-strength bolted connection node of our country in the past mostly are the mechanical properties researches at room temperature or after fire. In this paper, we have researches which are the performance of connection node in high temperature environment, and we have focused on friction coefficient, pre-tension change of high-strength and the performance of connection node in high temperature. Then we will fit analysis the results of these test. It will provide domestic study with some reference data which were the mechanical properties of steel on fire.The changes of friction coefficient directly affect the mechanical properties of friction high-strength bolt connection node, and temperature is an important factor of the plate friction coefficient. In this paper, we have a research about the friction coefficient of friction high-strength bolted connection nodes which are made of the same batch of steel plate at high temperatures. We had studied the changes about room temperature、100℃、150℃、200℃、250℃、300℃to the friction coefficient. Through these we get that the friction coefficient of steel shows almost linear decline when the temperature is less than300℃.The pre-tension change of high-strength is the other factor which directly affect the mechanical properties of friction high-strength bolted connection node, and the temperature is also an important factor of the pre-tension change of friction high strength bolt connection node. In this paper we made three groups of a single high-strength bolted connection node ourselves, we have studied the impact of high temperature to high-strength bolted strain. Through this test we have mapped out the temperature-bolted strain curve, and we would fit temperature-bolted pre-tension change curve further. We can also get the variation of the high strength bolt when the temperature is less than300℃In this paper we used smart box-type high-temperature to heat six sets of standard connection node specimen, this temperature would been kept for half an hour, and we used the servo loading instrument to stretch the components which were heated. It is considered separately the effect of room temperature、100℃、150℃、200℃、250℃、and300℃to the force performance. We will focus on failure modes、load-displacement curve and slip displacement of the performance. We get the conclusion that the temperature increases, the slip failure of connection node appears earlier, the slip displacement decreases, and the slip load also decreases. We also get that the slip load shows linear decline when the temperature increases. And we will fit analysis the result with the friction coefficient and the change pre-tension which is after high temperature, we get that when the temperature is less than300℃, the anti-slip coefficient shows linear decline and temperature influence anti-slip coefficient greater than the dynamic friction coefficient of the friction pair test.Finally we use the ABAQUS software to establish the finite element analysis model of connection nodes; we get the conclusion that the results of the finite element analysis model fit the results of the experiment well at room temperature and300high temperatures; it shows a true slip performance of the connection nodes.