Research On Energy Dissipation Performance And Welding Heat Effect Of Shear Mild Steel Damper

At present,energy dissipation and vibration reduction technology has been widely developed in structural applications.However,the energy dissipation and vibration reduction technology in China is still not mature,and the performance of the damper is difficult to be well guaranteed.The shear-type mild steel damper has the advantages of simple structure,stable performance,strong performance capability,and little influence by the excitation frequency,which will not affect the period and vibration mode of the structure and has good durability and other characteristics.This paper mainly studies the low-yield point soft steel LY160 as the energy dissipation plate of the welded shear type damper.Using numerical simulation and experimental measurement methods,we want to combine the energy dissipation and shock absorption performance of the welded shear type damper and the distribution of welding residual stress.Conduct regular research.The main research contents of this article are as follows:(1)Analyze the structure and damping mechanism of welding shear type dampers and the damage caused by welding,design two kinds of energy dissipation plates of different materials,soft steel dampers and ordinary steel plate dampers,using finite element simulation software ABAQUS conducts numerical simulation to simulate the impact of hysteretic performance and energy dissipation performance of two different energy dissipation plate materials.Whether the energy dissipation plate is a soft steel damper with low yield point,whether the energy dissipation and damping performance is better,determine the shear Selection of cut-shaped steel plate dampers.(2)Through numerical simulation of SYSWELD welding,we realized the movement of the heat source on the welding component to simulate the welding process.First,by controlling three sets of different welding currents and studying three sets of different preheating temperatures,we conducted thermal coupling analysis of the temperature field and welding The distribution of residual stress and whether controlling the welding current and preheating temperature can effectively reduce theinfluence of welding heat.Provide the perfect performance of soft steel damper for the follow-up.(3)Set up carbon dioxide gas shielded welding experiment and laser welding experiment,observe the macro and micro of the component,study the difference of welding technology,observe the difference of welding heat effect;compare the data,analyze whether the improvement of welding technology can effectively reduce welding Thermal effects.Measure the Vickers hardness of the base material area,welding heat affected area,and welding fusion area,analyze and compare the Vickers hardness of each area,know the flexibility of welding in each area,prepare for welding in advance,and avoid welding ring breakage.(4)Measure the distribution of welding residual stress by blind hole method to verify the accuracy of welding simulation.It provides a reference for the subsequent research on the design of the damper and the welding residual stress.Calculation results show that:(1)LY160 low-yield point mild steel shear-type mild steel damper with energy dissipation plate has better hysteretic performance and energy dissipation and shock absorption capabilities.(2)In the simulation of mild steel damper welding,the size of the welding current has a great influence on the size and distribution of the welding residual stress.In actual production,a smaller welding current can be used to effectively control the reduction when the welding requirements are met.Thermal effect of small welding effect on the damper.(3)The preheating temperature of the mild steel damper before welding has a significant difference to the temperature field and welding stress.Appropriate preheating temperature can reduce the welding residual stress.Too high preheating temperature will greatly increase the soft steel damper The welding residual stress can bring a certain degree of adverse impact on the structural performance of the damper.In the subsequent production of soft steel dampers,proper welding preheating temperature can be used to effectively reduce the welding heat effect.(4)Different welding techniques and the influence of welding heat are inevitable.In the welding process of gas shielded welding technology and laserwelding technology,coarse Weissite and bainite appear in the weld and the heat affected zone of the weld.Affect the welded structure,make the structure less flexible,and the structure is prone to fatigue failure.The maximum Vickers hardness of carbon dioxide gas shielded arc welding is in the heat-affected zone of welding,and laser welding is in metal fusion.During actual welding of the damper,more attention should be paid to welding in this area to avoid welding fatigue damage.Compared with the traditional welding process,the laser welding pool is smaller,the cooling speed is faster,and the heat affected area of the laser welding is smaller,generally1-1.5mm.(5)Using the blind hole method to measure the welding residual stress is basically consistent with the numerical simulation,and the error is within 5%.Through the research in this paper,it can be confirmed that the shear type soft steel damper has excellent energy dissipation and shock absorption performance,and the initial understanding of the distribution law of the welding residual stress of the damping is studied.In the future,the design of the soft steel damper or the distribution of the welding residual stress will be further studied.,Control,reduction and other issues provide reference,which is conducive to the improvement of damper products.