Dynamics Analysis And Numerical Simulation On The Major Girder Of JQ900 Crane

Major girder metal structure is one kind of the most important load-carrying structure of crane whose mechanical capability effect the whole machine's running directly. So it is necessary to analyze different kind of stress and pressure on the major girder to ensure it can run directly. Nowadays, the analysis on the girder is only focus on the static stress, and does little about the medal and the contact pressure. However all this aspect may possibly affect the major girder's mechanical capacity directly or indirectly. With the development of crane toward heavy stress, traditional static stress analysis cannot satisfy the requirement of design, so contact analysis and modal analysis is necessary. In system of the crane, the roll of crane and the major girder is a couple of contact element, since the roll rolls on girder frequently, it may bring contact pressure what can probably result fatigue of the girder. However the contact stress have not been calculate accurately. Beside when it is running, it may suffer from oscillation when its working station changed suddenly. Surrounding the above problems, based on the finite element method (FEM), elastic mechanics, contact mechanics, mechanic vibration theory and using parameterized method and the FEM simulation software-ANSYS to analyze the contact stress and modal situation. The main research contents and results of the dissertation are as fellows:1) To build a major girder and roll of the crane structure's parameterized FEM model using ANSYS internal command. Besides two part of model aboutthe major girder and the roll is build. Between them contact element is build using field-field to analyze the contact stress.2) To check the security of contact fatigue of the major girder after results is given based on the capacity of the material.3) To analyze the stress of the major girder when we calculate the contact pressure. And show the tend when the roll is rolling.4) To do the modal analysis on the girder, and calculate the inherent frequency and shape of oscillation. In this system the oscillation we analysis is without resistance. The order we analyze this is to avoid the happen of resonance in working.