Research On Rapid Algorithm Of Boom Stability Based On FEM

Truss booms are widely used in large engineering machinery equipments and its stability analysis is extremely necessary and more difficult parts in design work. Taking crawler crane for example, conventional design method in which stability results were concluded by complex finite element model applies to the situation which specific parameters were certain. However, due to the uncertainty of structure parameter, it is unable to create complex truss finite element model of boom system quickly in the early stages of product design of crawler crane. In order to improve design efficiency and accuracy, it is necessary to find an efficient and accurate method to simplify boom for the calculating work of crawler crane is numerous and tedious.Based on the above background, crawler crane was taken as an example for the in-depth study and research of truss boom stability. An algorithm which was relatively accurate and a system which achieved parametric, automation and continuous calculation of boom system stability were discussed in this paper.In order to achieve the overall stability algorithm of boom system, the work principle of boom system, loading condition and mechanics model of boom system were analyzed. Due to the disadvantage of conventional boom stability analysis method, it is necessary to work out a stability algorithm of boom system based on finite element method. Finite element model was established by the application of Timoshenko beam which could quickly calculate the boom stability results in the early stages of product design. The method of equivalent inertia moment which greatly improves modeling efficiency was adopted to transfer truss boom to Timoshenko beam. In order to ensure the accuracy of the results, the equivalent method should be modified. Tapered truss boom was converted to multi-stage ladder column instead of converted to Timoshenko beam by tapered coefficient μ2and the results showed that this method could meet the computational accuracy. Base on the method of equivalent inertia moment, nodes and elements could be calculated, and then simplified finite element model was established. Meanwhile, the stability coefficient of boom system was obtained rapidly by using finite element buckling theory. In order to improve design efficiency, a design system which achieved parametric, automation and continuous calculation of stability coefficient was established.Finally, taking750-ton crawler crane for example, calculating results obtained from ANSYS model and simplified model in this paper were compared. The results showed that the stability algorithm and system not only were parametric, automation and continuous but also were efficient and the most calculated results met the engineering accuracy requirements. However, some results were questionable. The error analysis of results was calculated and further research was proposed in this paper.