Research On Mechanical Characteristics And Fatigue Failure Mechanism Of Multilayer Strand Rotation-Resistant Ropes

With the rapid development of the global economy,the ports,mining,construction,logistics and other industries are also developing rapidly.The wire rope as the key transmission parts in lifting,transport and carrier device,is beingwidely used in more and more fields.Its quality and performance requirements are also increasing.Multilayer strand rotation-resistant ropes have micro-rotation advantages,but in the course of working,prone tosevere internal wear and sudden strands fracture,which affectingthe performance and service life andsafety.So there is a very important significance toresearch mechanical characteristic,damage failure and fatigue life of Multilayer strand rotation-resistant ropes,in order to improve structure and performance of wire ropeandreduce breaking accidents and waste.In this paper,Multilayer strand rotation-resistant ropesof 18×7+IWS is the main research object.Mechanical characteristic of wire rope in straight and bent state are analyzed and simulated.And through bending fatigue and wear test,failure form,fatigue life and injurymechanism of wire rope is researched.The main research contents are as follows:(1)According to Costello's elastic mechanics theory in ordinary wire rope,the mechanical model of Multilayer rotation-resistant wire rope in straight and bent state is established.Based on this model,the response of tensile stress,bending stress and contact stress in straight state and the distribution of bending stress when bending over sheaves of wire rope is calculated and analyzed.(2)Based on mathematical knowledge of differential geometry,Frenet frame and space coordinate transformation,etc.,mathematical model of the wire rope in straight and bent state is built,and the wire rope geometric properties of two states is analyzed and calculated.(3)The geometric solid modeling of Multilayer strand rotation-resistant ropes is established through Pro/E software.Combine with ANSYS Workbench software,afinite element model of wire rope is generated.Numerical simulation of wire rope in two state is performed,and wire stress,deformation distribution and relatively stagger displacement in the different strand is analyzed.Comparing with theoretical calculations,the correctness of the model is verified(4)The cumulative fatigue damage and the wear evolving model of inner and outer strandswire is initially studied in theory.And through bending fatigue and wear test,the failure form of wire rope and the fracture,wear of wire ropeexternal and inner wire is analyzed.Position distribution of wear spot of inner and outer strands is also analyzed.At last,the fracture failure mechanismof broken wire in different locations is studied.