Development And Application Of Reliability Analysis Software For Crawling Crane Boom

Crawling crane boom is the main load bearing part in structures of crawling crane. Because of complex structure and various loads, strength, stiffness and stability of crawling crane boom are all research emphases for designers. With continuous development of reliability technology, designers attach more and more importance to reliability analysis for crawling crane boom.At present, the technology of finite element analysis has already been accepted by most designers as a necessary skill in engineering applications. When crawling crane boom is analyzed by ANSYS, much time will be spent on building geometric model, meshing, loading and post-processing for complex operations. And, because of same structures but different dimensions, building similar finite element analysis models of serial crawling crane booms repeatedly will waste a great deal of time.Aiming at all the mentioned questions from above, this paper confirms distribution patterns of random variables by analyzing the parameters of crawling crane boom. Element types, loading methods, constraint conditions for boom structure are chosen by the characteristics of boom structure and its loads. This paper use ANSYS parametric design language APDL to build finite element parameterization model of crawling crane boom. VC++as a kind of programming languages is used to develop a reliability analysis software system for crawling crane boom. The reliability analysis software can achieve functions like data input, reliability analysis, results deal with and so on.Base on the failure modes of crawling crane boom, this reliability analysis software analyses the stiffness, stability and reliability for crane boom. The largest displacements in turning surface and range changing surface can be both obtained from the results of static analysis for different conditions of crawling crane boom by using the reliability analysis software to invoke ANSYS. Stiffness requirements are satisfied or not in different conditions of crawling crane boom can be judged by the largest displacements. When structure of crawling crane boom becomes buckling, critical value of weight for crane can be gotten form buckling analysis which considers geometric non-linearity of crane boom by this software. And, arc-length method is chosen as the method of equilibrium iterations for loads. Many random variables generate in the process of design, manufacture and working. Considering the influences of random variables on performance of crawling crane boom, this reliability analysis software chooses Monte Carlo probabilistic finite element method and correlated failure model of series system to analyze reliability of crawling crane boom. Meanwhile, the reliability analysis software can also obtain the main random variables which affect reliability of crawling crane boom and how much their influences will be by sensitivity analysis.This paper analyzes the stiffness, stability and reliability of crane (QUY50A) by this reliability analysis software. Stiffness requirements and stability requirements for crawling crane boom are both judged and reliability of whole boom and elements for crawling crane boom will be analyzed. Meanwhile, we can also obtain the main random variables which affect reliability of crawling crane(QUY50A) boom and how much their influences will be by sensitivity analysis. Analysis results of the example indicate that structure of the software and operation is simple, speed of model building is quick, the results are believable, unnecessary and repeated works can be avoided.