Research on Improvement of Clamping Device for Online Nondestructive Tensile Testing of Braided Wire Rope

Abstract

The online nondestructive tensile testing machine can crush wire ropes, during the safety tension test of braided wire ropes. To solve this problem, this paper analyzes the reasons for crushing phenomena from the aspects of static simulation and geometric analysis of wire ropes. In terms of static simulation of the tensile process, the equivalent stress, contact pressure and contact gap cloud map of the wire rope in the clamping jaw range are obtained. It is found that both equivalent stress and contact pressure of the wire rope reach maximum values at the transition section between the adjacent peak and trough of the sinusoidal curve, while both reach minimum values at the position of the peak and trough, where the wire rope is in a non-contact state. Concerning the geometrical analysis of the clamping surface of the jaws, the results show that the normal distance between the sinusoidal curves of the movable jaw and the fixed jaw is not constant in one period, which is the smallest at the transition section between the peak and the trough. Therefore, our group determine the destruction resulted from the unreasonable curve shape of the clamping surface, further improve the jaw curve and realize the non-damaged safety tension test of wire ropes.