Optimal Structure Research For Jib System Of Elastic Four-bar Linkage

Luffing gear is an important mechanism of jib cranes. Designing the structure dimension of four—bar linkage Jib system is the main tache which affects the integer characteristics.Traditionally, Jib system is considered to be rigidity whose process was divided into several parts. The model was built by fix-point analyse. More emphasis was put on the power of luffing gear rather than intensity condition of metal structure.The jib system of portal crane is considered to be elastomer in this paper. Besides, taking finite element as basic theory and mechanical dynamics as analysis method, the paper simulates the virtual luffing process of jib system and seeking the relationship between plane movement and dynamic pressure condition of jib system using ANSYS8.1. By analyzing ,the paper gives some advice on structure optimizing.Main contents:(1) The paper introduces the structure form of portal crane jib system and analyses the working principle, process, parameters affection of four—bar portal crane.(2) The paper builds finite element model of portal crane jib system using girder element, besides it presents its principles and process so that the foundation of this method is established. Besides, the paper builds the model in APDL which is easier to modify and administrate.(3) The paper builds Transient dynamics model of jib system by ANSYS8.1 and analyses its results combined with crane metal structure theory. It also achieves some valuable conclusions to improve the gravity contrail and reduce gravity.(4) The paper analyses the dynamic characteristic and picks up the result of key load-step and entire contrail curve.(5) The paper gives advice on optimization of jib structure by analyzing the result of elastomer transient dynamics.