According to the standard: TB/T2073-2010 General technical specification of fittings for overhead contact system in electrification railway

Dropper fatigue testing machine, includes upper support, lower support, force applying part, force buffer part and sensor, the force-applying part is disposed on the lower support, the force buffer part is disposed on the upper support, the sensor is fixed on the tension-buffer part, the dropper sample is placed between the force applying part and the force buffer part, and the bottom end is contact with the tp of the force applying part, the top end is fixedly connected with the bottom of the force buffer part. High-speed electric cylinder is used to load and unload the dropper sample from bottom to top, speed and displacement of each stage of loading and unloading can be controlled by a pre-programmed computer program. Complete compression in half a sine wave, and the dropper sample buffers the inertial force during the descent. The dropper sample clamps simulated stress state of dropper in the load-bearing cable, replaces the bearing cable with a spring, the buffer spring is in the vertical position, the lower end is fixed, and the upper end is floating, and cushions the inertial force acting on the dropper sample.