Analysis And Research On Overall Stability Of The Arms Of Crawler-Crane

With development of national economy and changes in construction methods, the Crawler Crane increasingly shows its superiority in engineering projects. As major bearing component, the boom system mostly uses high-quality and high-strength steel, and increasingly tends to be taller and softer, which makes the overall stability of boom system earn more and more attention. So far, the stability problem of a single beam has been comprehensively solved, but for the stability problem of complex truss members, using traditional mechanical methods is difficult to conduct accurately checking. Especially the stability problem of boom system with multi-component combination, the design manual does not provide parsing algorithm to work out. With FEA software been extensively used in engineering design, analysis and research on complex truss structure stability significantly progresses, but modeling process is cumbersome and workload is large. In this paper, overall stability of boom system is considered as main research object. The author conducts systematic study on simplified method of lattice boom with four chords, works out parsing algorithm of critical weight for boom system, analyzes influence regularity of parts’attribute parameters, uses APDL language and MATLAB programming, etc. The major research and achievements are as follows:(1) Based on the principle of critical force equation, the simplified method of lattice boom with four chords is researched on, with inertia moment equivalence. The lattice structure is simplified to be solid beam, and correctness of the method is verified through practical examples.(2) Linear elastic stability of boom system in main boom working case and tower jib working case is studied on, and booms’deflection differential equations in the rotation plane are established based on simplified mechanical model. Then parsing algorithm is used to obtain buckling characteristic equation, which is aimed to get critical weight in corresponding conditions.(3) The MATLAB program for boom system stability analysis of multi-conditions in main boom working case is written, so as to get critical weight table that is determined by overall stability of boom system. For a given condition in the tower jib working case, the corresponding MATLAB program is used to obtain the critical weight of the condition.(4) The regularity of boom system component is researched on with components’ attribute parameters changing. The range of components attribute parameters is recommended. which can provide design reference for effectively enhancing the overall stability of the boom system.(5) Different influence of boom system’s overall stability is analysed with components’ attribute parameter changing in conditions with high elevation angle and low elevation angle of tower jib, in order to identify important factors of system stability for the two different elevation angle conditions.