Nonlinear Stability Analysis Of Crane Lattice Boom

With the needs of engineering construction, the crane is designed more and more large, towering, svelte and lattice. Because of the extensive use of high-strength steel, the structural strength is improved, but the rigidity and stability of lattice boom is increasingly evident. The stability of complex lattice boom has become a calculation difficult of large crane. Crawler crane boom system is the space lattice structure. The traditional mathematical models and mechanical methods have been difficult to accurately check its stability. Therefore, we must seek a reasonable crane booms nonlinear stability analysis method for accurate calculation.Practical problems for the above, this paper take160t crane for example which produced by a corporation. Based on the analysis of structural features of crane boom, the mechanical model is established and used to analysis the strength and strut stability of the boom, the maximum stress of the strength and stability are432.24MPa and509.7MPa, both of them are less than the allowable stress which is510.4MPa, which meet the requirements of strength and stability of struts and provide a reference for the finite element analysis software. A finite element model of the boom is created in finite element software ANSYS. Static intensity and strut stability are analyzed with the model, and the maximum stress is430.291MPa. Then the eigenvalue buckling analysis is done. The eigenvalue buckling mode shape as the initial imperfection is used to nonlinear buckling analysis. The maximum of the nonlinear buckling analysis is503.828MPa. The results of finite element analysis meet the requirements of strength and stability of struts.The results of finite element calculation were compared with the results of crane design standard formulas calculation, errors are below2%, verified the correctness of finite element analysis results. The influence of lateral force, rotary inertia force and wind loads on the nonlinear stability of the boom were analyzed. Because of the boom lateral force generated stress is32%in total stress, so the lateral force is the main factor leading to instability of the boom. When appropriate to reduce the rotation speed and acceleration, the stability of the crane boom can be improved, but the efficiency can’t be reduced.