The test machines (materials testing equipment) that can apply to dynamic loads (fatigue studies) and/or static loads (to control the angle Error of load) are the used ones to verify the mechanical efficiency of the welds. The flexion type of test implies the accomplishment of a test of flexion in four points, applying a cyclical load to verify the yield of the weld concerning the fatigue. The load will be applied of sinusoidal form, which will go from the value of fully factored load to 90% of that value. This tension will be repeated during five million cycles or until the weld fails. If the failure takes place, the piece must be marked and the series which belongs rejected.
One is to reproduce a periodic load of constant amplitude, by three million Cycles, in a position and an angle that the real tension simulates that exerts a train of wheels in the line of railroad. The magnitude of the load and the position of the actuator (angle of application of the load) will be determined from the value OF vertical dynamic rigidity of the plate that indicates the line of railroad. The materials that are used are of polymer, for the following reasons: – Isolation: essential to guarantee that interferences do not take place. – Comfort: It has an absorption of high level/damping qualities. Therefore, he is essential to confirm the validity of the benefits of these materials when they are put under high tensions. The normal charge for this 95 test are 25 and kN, and they are applied during a minute. – Tensile strenght: Looking for the residual deformation of the coil.
A load of 20 kN will be applied to the case of constant form. Later, the load is increased until a maximum of 1.1 kN by each mm of inserted coil. This load stays during 2 minutes before the liberation of the load of until 20kN again. Once it spends a minute with this last load, the deformation is moderate. The value of this residual deformation must be smaller to 0.35 mm – Value of the breakage by traction: The value average must be greater of 1.65 kN by mm of inserted coil. First aplica1,1 kN by each mm of inserted coil. If the case is broken, value 1,1 is registered. If there is breakage of the no load it increases until the breakage or 2 mm kN. Test under lateral load is used a device to simulate the lateral load of the railroad. This lateral load is of the type of compression for the part at issue. The conditions of test are the real conditions of operation. Felipe Garci’a is consulting of Ibertest the International Materials Testing.