Research Of Boom's Auxiliary Bracing Based On Nonlinear Bending Theory

Crawler crane is an indispensable construction crane. With the development of the economy, it develops to the direction of large tonnage. The boom also becomes much longer. As main bearing weight structure of the crawler crane, the quality of boom directly affects the whole machine's operating performance. The length of boom determines the load's height and range. For the problem of long boom leading to worst stress state of the boom, auxiliary bracing is used to improve boom's stress. So, the research of boom's auxiliary bracing based on nonlinear bending theory is very important. It can make a significant contribution to improve the performance of crawler crane's boom.This paper takes 500t and 80t crawler crane's main boom for research object. The length and the location of the auxiliary bracing are analyzed in detail. Combining with stress and strain of the whole boom system under the nonlinear bending condition, the design of the auxiliary bracing is finished.This research starts with the analysis of displacement which affected by the gaps of parts'clearance fit, and the model of boom is created. According to wire rope's stress statement in real, a method is proposed in modeling the wire rope by element type beam188 in ANSYS. Then, three mechanical models'advantages and disadvantages are analyzed and compared, and a suitable to ANSYS calculation method of nonlinear analysis has been selected. Using ANSYS software and APDL language, the paper analyses the boom's deformation statements under different amplitude working conditions. Through the example proves the conclusion that the length of wire rope should be identified in the minimum amplitude working condition. Based on this conclusion, constantly adjust the auxiliary bracing's installation location on the loom, also through analyzing and comparing the deflection and stress under the condition of raising boom, and ultimately fixed the best installation location of auxiliary bracing. At last, an improved advice for the boom structure of auxiliary bracing location is given, and proved its feasibility with ANSYS.The results of this study can not only guide this type of auxiliary bracing design, but also provide a well theoretical reference for other types of boom.