Fatigue Performance Test Of Spring Fasteners

The elastic strip is the crimping part of the elastic fastener. Through the bending and twisting deformation of the elastic strip, the buckle force is generated to act on the rail, and the reliable connection between the rails is guaranteed for a long time. Common spring fasteners include type I, type II and type III, all of which are to maintain the integrity of the track as much as possible, prevent the vertical and horizontal movement of the rail relative to the sleeper, and ensure the normal gauge, so as to ensure the safety of rail vehicles. The elastic strip of the clip fastener works under repeated alternating stress, which has many functions such as bending, torsion, fatigue and corrosion. When a vehicle passes by on the track, it needs to withstand a high instantaneous impact load, so the performance requirements for the clip fastener are very strict. The inspection items of spring fasteners include form size, mark and factory standard, appearance, crack, hardness, metallographic structure, total decarburization layer, residual deformation, buckle pressure, fatigue performance and rust resistance performance, etc. Next, I will introduce you to the fatigue performance test!
Place the test clip on the measurement platform, measure the relative elevation of the front end of the middle section of the clip with a dial indicator, and record the accuracy to 0.01mm, and then assemble the clip so that the root of the clip is embedded in the arc of the hard metal embedding block Inside. After the loading head of the fatigue testing machine touches the loading beam, it continues to displace downward relative to the base plate of the loading device to reach the design assembly displacement of the elastic bar, and on this basis, continue to apply a certain range of dynamic displacement, and re-measure according to the initial method after a certain number of cyclic loads The relative elevation of the front end of the middle section of the elastic bar shall be judged according to the test results.