Nonlinear Calculating Method for Multi-Bar Luffing System of Giant Crane Considering the Sagging Effect

The luffing system of giant jib crane is usually consisted of rigid bars and flexible cables, and the weight of components causes sagging deformation and large displacement. In order to study the nonlinear method for multi-bar luffing system of giant jib crane, this paper completed theoretical analysis and example verification. Based on catenary theory, the equation of luffing strand was obtained. Spatial multi-bar equation of three bars was proposed and it was extended to any more bars. Then, equilibrium equations of components were written in sequence, and the equations of multi-bar luffing system were established with the elastic deformation of multi-bar and luffing strand. Finally, by taking the 2500-ton ring crane as an example, the results demonstrated that: the nonlinearity of combined multi-bar luffing system negatively influences the structural behavior, and the results calculated by the proved nonlinear method is more reasonable and closer to the actuality than the linear method, so it provides theoretical basis for engineering design and construction.

Kinematic Matrix Method of Portal Crane Boom System

To research the laws of barycenters of construction members of luffing system is significant. The kinematics of four-bar luffing jib multi-rigid body on portal crane is studied with mathematical matrix method which is convenient for programming calculation. These moving laws are concluded by visual software exactly. The mathematical formula which is the basis of modern design of luffing system is established. Then the cargo movement track and amplitude inertia force are counted handily. Matrix equation is verified by citing case study.

Dynamic Characteristics Simulation of Luffing System for Aerial Work Platform Truck Based on Matlab/Simulink

In this paper, the principle of work of aerial work platform truck luffing system is introduced and The mathematics model is established. With Matlab/Simulink software, the simulation model of luffing system is constructed, meanwhile the dynamical characteristics is implemented. With the research work of aerial work platform truck luffing system, this paper provides theoretical foundation for design and improve of luffing system