Design And Mechanical Property Analysis Of An Extra-Large Flexible Hoisting Cage

The development of extra-large flexible hoisting cages in China is still at its early stage. This type of hoisting cage usually bears a large load and deformation. As a result, deformation of the cage body tends to influence the interactions between the cage and the guide, the steel ropes, and the cage resting/supporting devices. This thesis designs a flexible hoisting cage and analyzes the mechanical properties of the cage under conditions of offset loading. A 3-D model of the hoisting cage was established. A set of parametric algorithms for finite element analysis were developed. The structure of the cage frames was examined. Nonlinear analysis of the flexible cage under static off load, random fatigue analysis were all conducted. Form of the vertical beams, configuration of the cage ears, and influence of the oblique beams on cage body strength and stiffness were discussed. The stiffness distribution of cage ears and vertical beams was optimized. Responses of cage body deformation and internal forces to the varying loads were studied. These work offered necessary database for the design of an extra-large flexible hoisting cage. Considering the mechanical properties of the vertical beams, bending deformation of the slender beam was investigated when the superposition principle did not apply. The equations for calculating deflection and section stress and strain were given. Deformation characteristics of the beam bearing dynamic loads also were discussed, and the results from which were used in the mechanical calculations of the cage body. The cage body is a statically indeterminate structure. Regarding the cage frames as rigid structures, a statics model under planar offset loads was built in this work by combining the force method and the displacement method and employing moment equations, deflection equations, and bending angle equations of the vertical beam,balance equations of the cage frame, and geometric continuity equations of the cage body. A volumetric statics model of offset load then was built using the rotation transformation matrix. Considering the influence of cage guide defects on flexible hoisting cage during lifting, the interactive forces between the cage guide and cage ears also were studied in this work. The kinetic equations of an extra-large flexible hoisting cage during lifting with offset loads were derived. The same method also can be applied to mechanical analysis for the cage under other different conditions.