Research On Elastic-Plastic Hysteretic Performance Of H-Shaped Steel Seismic Reduction Damper

Every year the earthquakes happen around the world. China suffered a lot due toits geographic location, and a few years ago just happened devastating earthquakessuch as Wen chuan earthquake, Qing hai yu shu earthquake. As the traffic throat,during the most bigger earthquake cases the bridges suffered from more or less damagessuch as the beam dropping from the bearing, listing even complete collapse. So, howto increase the anti-seismic capacity of the bridges is well concerned by the engineeringcommunity. The scholars at home and abroad brought out many ways and one effectiveof them is using the plastic ability of the soft steel dampers. Having the advantages ofstable hysteresis loop curves, better low cycle fatigue ability, simple formations andlower price comparing to others, it is popularly applied. At present, it has developedmany shapes like U-shaped, Triangular and X-shaped. Basing on the existing researchresults at home and abroad, the thesis brought out the hot rolling H steel made byChinese standard as the material of damper for superstructure of bridges to resist theearthquakes. The H-shaped dampers consume energy by the plastic hinge causing bythe yield strength of the soft steel, and comparing to other soft steel dampers, it has thecharacters of simpler formations, higher yield strength, better effect and easily madeand installed.The main contents of the thesis are as follows:Reviewed, summarized the characters of bridges’ damages under the earthquakesand soft steel dampers’ existing research results at home and abroad, and brought outthe hot rolling H steel made by Chinese standard as the material of damper forsuperstructure of bridges.Designed and made full scale of H-shaped dampers’ samples, carried outlow-cycle fatigue experiment of H-shaped dampers, fully researched its hystereticperformances like yield strength, hysteresis ductility, curvature distribution of plastichinge area and the length of the equivalent plastic hinge combining with ANSYS modeland built the model of simplified hysteresis and the length of the equivalent plastichinge.To the common multi-span simply supported girder bridge, applied the H-shapeddampers as the seismic reduction parts and the simplified hysteresis model was used tocarry out the elastic-plastic dynamic time-history analysis to compute the seismicreduction effect of the H-shaped damper, proving that it can effectively reduce seismic response horizontal displacement and it is a good performance and easy applicationmeasure to reduce seismic response.