Study On The Response Of Composite Crossarm Under Dynamic Load

In recent years,due to frequent wind disasters on transmission line towers,tower collapse accidents of varying degrees have occurred,and various regions are also facing huge economic losses and casualties.As a very important part of transmission line towers,composite materials are studied.The mechanical properties of the cross arm are of great significance to engineering applications.In this paper,the composite cross arm of 500 KV transmission line is the research object.According to the design conditions of the composite transmission tower,the modeling process of the composite cross arm is modeled,and the modal analysis of the composite cross arm is carried out using SNSYS software.The transient dynamic analysis under wind load verified the excellent fatigue resistance of the 500 KV crossarm specimen through high-cycle fatigue experiments,which provides reference value for future engineering applications.The main research contents of this paper are as follows:For the 500 KV composite cross arm,using ANSYS finite element analysis software,the composite cross arm was analyzed without prestress and under the action of line load.The vibration mode and frequency obtained from the two working conditions were compared.The wire load has a greater restraining effect on the cross arm.The transient dynamics simulation analysis of the composite material cross arm under the average wind load and the fluctuating wind conditions was carried out.The stress,strain,and displacement time history curves obtained in the two conditions were compared,and it was found that under the same environment,The cross-arm structure subjected to fluctuating wind load vibrates more severely.Through theoretical analysis and experimental research,a test platform was built for dynamic experiments of composite crossarms,and the fatigue characteristics of crossarms were tested.It is found that the load bearing performance of the cross arm is good.The root stress amplitude increases continuously with the increase of the order frequency,and changes in a sinusoidal curve.The peak and valley values of the stress are relatively stable,indicating that the cross arm has been in the elastic force change,reaching Experimental expectations.