| MR(magnetorheological)damper is a semi-active damper device,which have plenty of advantages such as making structure simplification,providing reverse damping force adjustment,continuous,and apace responding adjustable range.Recently,MR damper has been widely used in structural engineering.The situation of MR damper in the natural environment is very bad,and its performance will be degraded in the long term,which will affect the damping effect.In order to research on the mechanical properties of MR damper after long-term use,this article selected30 MR damper which worked ten years,and marked mechanical performance test,by comparing the performance analysis and new damper,and researched on the mechanical models and model parameters optimization,performance degradation and other reasons,the main the research contents include:(1)The article introduced the research status and application of cable vibration control in damper on large span cable stayed bridge,summarizing the basic theory of MR damper.And it mainly concluded the mechanics model of the MR damper.(2)The article tested the ten years work of RD-1005 type MR damper to find mechanical properties,mainly through the experiment of MTS material testing machine,the experimental data and the experimental data with the new RD-1005 type MR damper were analyzed and summed up the different voltage,different amplitudes and different frequencies of mechanical properties,for example,a force amplitude,equivalent damping coefficient.(3)The article analyzed the reasons of decreasing,mainly summarized the influences above precipitation of MRF,installing angle of damper and oxidation of iron particles to mechanical properties.(4)According to the experimental results,article proposed the modified Spencer mechanics model of MR damper,and its can describe more accuracy mechanical properties which was used MR damper.And use particle swarm algorithm optimize the parameters of modified model which can reflect the mechanical properties of the used damper. |
