Optimization of mobile crane boom using the finite element

Abstract

The topic regarding the present thesis is the optimization of the boom of a mobile crane mounted on a pickup truck. The most important definitions were defined, and the types of truck- and mobile cranes and their features were presented. The operation of the typical boom-moving mechanism for this category was shortly explained. The mobile crane to be optimized was also presented, as well as the requirements set up for it and the parameters of the final construction. I studied the crane boom sections available on the market and compared them based on their most important physical parameters (mass, second moment of area, area, volume) and discussed their advantages and disadvantages. After selecting the appropriate cross section, it was optimized for the given load. For the optimization the method of Lagrange multipliers was used, which is a very common method in engineering optimization and perfectly applicable for the present issue. I determined the optimal dimensions of the main boom section. The 3D model was designed in Solid Edge. The value of the weight loss achieved compared to the original boom system was determined. Then an alternative solution wasstudied to achieve even greater weight loss. Since I wanted to show the importance of FEM simulation in engineering optimization, the history and essence of finite element method was briefly introduced. The simulation was carried out in Femap. The steps of the simulation, the load, the constraints and the results were presented. At the end of the thesis the results achieved were summarized, and also some advices for further future improvement possibilities were formulated.