| Highway transportation is the main mode of freight transportation in our country.As an important part of highway,the bridge’s expansion device is one of the most vulnerable weak links.So far,the research on its mechanical performance has not attracted enough attention.In this paper,the finite element analysis software ABAQUS is used to build the model and the subroutine is used to load.The static analysis and dynamic analysis are carried out for the comb plate expansion device,and the response of the expansion device under the vehicle load is studied.The main research contents and results are as follows:(1)This paper introduces the engineering background,analyzes the expansion and contraction parameters of the comb plate expansion device,and establishes the analysis model of the expansion and contraction device with ABAQUS finite element software.(2)The static response of the comb type expansion device under vertical static load,vertical and vertical horizontal static load is studied.When two lanes are arranged,the static response of the load at different positions in the longitudinal direction of the bridge is calculated,and the influence of the joint width on the expansion device is analyzed.When three lanes are arranged,the influence of the cross slope and the longitudinal slope on the expansion device is analyzed.The research results show that: when the load is above the gap of expansion joint,the stress is the most unfavorable;the larger the width of the joint is,the more unfavorable the stress on the expansion device is,the expansion joint should not be too wide;it is safer and more conservative to calculate static response with impact coefficient;the influence of cross slope on the expansion device is small,when the longitudinal slope is positive,that is to say,the downward direction of the bridge is downward,it is unfavorable to the stress.(3)Based on the dynamic analysis method,FORTRAN language is used to program the subroutine to realize the dynamic loading,and the dynamic response of the comb plate expansion device under the moving vehicle load is studied.When the vertical load is applied,the influences of the parameters such as velocity,joint width,axle load,transverse slope and longitudinal slope on the vertical displacement and impact coefficient are analyzed.When the vertical and longitudinal horizontal loads are applied simultaneously,the influences of the parameters such as velocity,joint width,transverse slope and longitudinal slope on the dynamic response are analyzed.The research results show that: the overall trend of impact coefficient increases with the increase of vehicle speed,but there are local extreme points.With the increase of axle load,the change of impact coefficient is not linear;the transverse slope has little effect on the dynamic response of the comb plate expansion device.When the beam end of the bridge is higher and the direction of the lower bridge is downhill,the stress on the comb plate expansion device is more unfavorable;it is suggested that the movable comb plate should be installed on the side behind the vehicle during construction.The joint width of the 80 type comb plate expansion device should not exceed 70 mm.When the vehicle passes through the expansion joint,the brake should be avoided. |
