Parametric Design And Fatigue Life Analysis Of Gantry Crane's Metal Structure Based On ANSYS

Gantry crane is the main handling machinery in the open-air container yard, the U-shape metal structure of gantry crane is the preferred one, because of its good force state and large space between the legs. But the design process of gantry cranes is very complex and obscure. Actually, many similar or duplicate works have been done in cranes design of the same type but different specifications. So, engineers need to spend so much time on building the finite enlement models of cranes that delay the designing cycle and the update speed of crane severely. In addition, the structural design of cranes mainly check the strength and stiffness, the fatigue is almost not considered, and the caculation methods of fatigue life are very tanglesome. In fact, the fatigue failure of lifting appliances' metal structure is the one of main damage forms which determines the life of a crane. Thus, based on summing up the theory and method of parametric design theory, finite element method, fatigue life theory and so on, we developed and researched the parametric design system of cranes' structure based on the programming design software-Visual Basic and FEM simulation software-ANSYS. Then Paris formula is used to calculating extended life of fatigue crack of crane structure with ANSYS's auxiliary.This thesis mainly discussed as follows: firstly, based on a plenty of project examples and experience, in the view of common element type in gantry crane FEA, discussing about how to establish a rational finite element model of gantry crane, and the treatment techniques and simplifying rules of finite element models of gantry cranes is researched. The paremetric modeling technology is used to build parametric general models of metal structure of gantry cranes by APDL(ANSYS Parametric Design Language). Due to the conveniention of VB in building GUI interface, the parametric finite element analysis system of U-shape gantry crane's metal structure can be developed with ANSYS, which realizes rapid modeling and analysising in definitive conditions. The system can provides practical platform which can analyze the metal sructure of gantry crane rapidly and simply to R&D designing engineers, and demonstrating the practical value of the parametric finite element analysis system of U-shape gantry crane's metal structure by a U-shape crane. By summing up previous experiments and research results, ANSYS's sub-modeling technique and stress intensity factor module is used to calculate crack's stress-intensity factor at a specific condition and length of crack, then the extended life of fatigue of structure can be obtained with Paris formula. It provide a new practical method to estimate fatigue life of gantry crane.