Study On Fire Resistance Of Glued-Laminated Timber Post And Beam With Mortise-Tenon Joint

Chinese ancient buildings is given priority to with wood construction and development and it is an important part of Chinese ancient cultural heritage. A large number of scholars have researched in the aseismic mechanism of mortise and tenon joint connection, but few of them have studied the fire resistance of timber post and beam with mortise-tenon joint. So when the ancient building is on fire, it will result in a large number of casualties and property losses. In addition, the indirect losses of ancient architectural art caused by fire can not be measured by money, because of its specific artistic value and humanistic value, and once burned, it could not be regenerate. So it is very necessary to strengthen the study on the fire resistance of glue-laminated timber post and beam with mortise-tenon joint.The paper is mainly based on fire tests of glue-laminated timber post and beam with mortise-tenon joint. Besides, on basis of the classic heat transfer theory and principle of finite element, heat-structure coupling models were established with software ABAQUS to analyse temperature field distribudion, charring rate of wood and fire endurance of glue-laminated timber post and beam with mortise-tenon joint.. Main contents can be divided into the following several parts:(1) Firstly we review and summarize the main work and achievements on wood fire resistance in domestic and foreign scholars, as well as point out the shortage of their research. Based on the above background and related work, The topic of academic ideas and research target is provided, Finally we briefly described the research work in this paper.(2) The timber material tests were carried out and the thermal performance and mechanical performance of wood under high temperature is summarized to provide indictors for the experiments and finite element numerical simulation.(3) One bearing capacity test of glue-laminated timber post and beam with mortise-tenon joint and three fire endurance tests of glue-laminated timber post and beam with mortise-tenon joint were conducted to analyze the impression of different load rations to temperature field distribution, fire endurance and failure mode of glue-laminated timber post and beam with mortise-tenon joint. It indicates that when load level is small, the damage is mainly in wood beam. When the load level is larger, the damage is mainly in mortise-tenon joint.(4) The finite element software ABAQUS was used to simulate the KJ-2, calculating its temperature field distribution and structure field distribution, and studied the effects of beam load on the fire endurance. It found that the the calculated results agree well with the test results. And when the load is larger, the finite element method of indirect heat-structure coupling can not Simulate the charring progress of the top of tenon because of the increasing gap between the mortise and the tenon.