Research On Seismic Damage-Control Fuses Used In High-Strength Steel Beam-to-Column Joint

As we all know China is one of the most earthquake-prone countries in the world.Although most of the new constructed structures in our country are now designed with the basic goal of " no damage under minor earthquake,repairable damage under moderate earthquake,and no collapse under large earthquake ".When these buildings are subjected to earthquakes that are more severe than the seismic fortification level of the region,buildings will be damaged or even severely damaged.Once damaged,it may take a long time to reinforce or even dismantle after earthquake,which means interruption or termination of the use function of those buildings.The disruption of important building functions will not only bring huge economic and property losses,but also affects disaster prevention,reconstruction and the stability of society.So that,it’s necessary to take steps to explore new structure systems and technical means for important buildings,in order to avoid the interruption of the use of buildings even after a severe earthquake.In this study,a novel high-elastic structure system based on high-strength steel is introduced,in this system a set of damage-control fuses are arranged at the ends of beams to protect the main frame from damage.A series of tests were conducted to investigate the performance of damage-control fuses and typical beam-to-column joints used in this system.The main work covered in this dissertation include:(1)In this paper,firstly,the development status of high-strength steel structure was summarized,what’s more the basic composition and working principle of a new high performance seismic structure system that based on high-strength steel and damage control fuses was introduced.(2)For ordinary steel beam-column joints and high strength steel beam-column joints which were constructed with traditional welding connection,a set of pseudo static tests were conducted to evaluate the seismic performance of them.Based on the tests results,the similarities and differences between those two kinds of joints were compared,especially on the respects of elastic deformation ability and reliability of welded connection.(3)Nine specimens of beam-to-column joints that are arranged with damage-control fuses at the ends of beams were carried out to study seismic performance of the joints used in new structure system.The main target of these tests was to validate the effectiveness of the damage-control effect of fuses.Based on the test results,the influence of several other parameters were analyzed,such as the design strength and the reduction section form to the seismic performance of the beam column joint with damage-control fuses.(4)Refinement finite element models of high strength steel beam-column joints arranged with damage control fuses were proposed,and the analysis results were compared to the test results in order to confirmed the simulation results.What’s more the strain and stress details of high-strength steel frame that arranged with damage-control fuses at the end of beams were analyzed by the finite element models.(5)Three finite element structural models were constructed,including a ordinary steel frame,a high-strength steel frame and a high-strength steel frame that arranged with damage-control fuses at the end of beams.A series of analysis such as modal analysis,nonlinear static procedure analysis and incremental dynamic analysis were conducted to have a study the seismic performance of high-strength steel frame that is arranged with damage-control fuses at the end of beams.