| The transition carriage is an important device in the process of ship launching, Its system consists of walking wheel (guide wheel, sliding wheel), axle, bearings, rails and other structures. Stress is very complex, in the process of ultra-low speed running, especially among the orbit seam shock is violent, Easy to cause instantaneous overload, contact stress increase, leading to the phenomenon of the deformation and fracture on the structure of wheel and wheel axle, etc. Once the wheel system damage will seriously affect the safety and stability of ship launching operation. With the rapid development of shipping industry, the tonnage and volume of the ship is more and more huge, which brings a severe test for ship launching work. In order to eliminate the risk of potential, improve the safety of ship launching, must study the reliability of the transition carriage.This article to take a transition carriage wheel/rail system as the research object, carry out the finite element simulation and experimental analysis, discusses the wheel-rail contact stress and the changes in the situation of axle and bearing stress and strain, analyzed the affect level by the speed, load and other parameters on the shock of wheel at rail joint, taking wheel bearing capacity test and verify the theoretical calculation and finite element analysis results. The main work and achievements are as follows:(1) According to the classical formula, calculated the bending stress, deflection of balance wheel and edge wheel axles and the bearing pressure p and pv value under different load, as well the contact pressure between the wheel and the rail. Results show that when the wheel/rail system under maximum load of400kN, the above parameters are within the allowable range.(2) Have established the finite element model of wheel system, taking the finite element simulation calculation of wheel axle and bearing in the stress and deformation and the wheel/rail contact pressure under different loading conditions. The results show that the stress and deformation of wheel axles and bearing and the wheel/rail contact pressure linear increase along with the increase of the load.(3) Using ANSYS/LS-DYNA dynamic analysis capabilities to simulated and analyzed the shock situation of the transition carriage wheel/rail system at the rail joint. In the process of shock, the maximum von Mises equivalent stress, the maximum contact stress and equivalent plastic strain are increase accompanied by the speed and load increases. Speed and load on the influence of rail is more obvious, but relatively small of wheel. To ensure the security of wheel/rail system, the marching maximum speed of wheel should be not more than6m/min.(4) Performing an pressure bearing experiment for wheel system. Based on the test data, analyzed the causes of the finite element calculation error, and corrected finite element model. Results show that the finite element calculation result tallies well with the test data, the error within2.5%, the indicators of wheel axle and sliding bearing meet the design requirements, the contact stress between wheel and rail is take the allowable stress range. |
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