Non - Probabilistic Reliability Analysis And Safety Estimation Of Crawler Crane Boom Structure

Crane application can be found all over engineering field, its security problem not only affects economic efficiency of the country and enterprises, and the more serious it may harm to people’s lives and property safety, it has be included in the state public security, and it has had strong concern and attention from all circles. For the crawler crane, arm structure is the main load-bearing structure, its security will determine the safety of the whole crane. As an important component of the crawler crane: arm structure, under the rapid development of social economy its safety and reliability is more and more important. The research on reliability method of crane structure has the certain economic significance and practical significance.Arm structure bears lifting load, vertical load and horizontal load. The parameters that affects these loads has uncertainty. Using the probabilistic reliability analysis method, due to structure characteristics and the working conditions requirements of crawler crane, the analysis needs a large number of statistical data of these parameters. The tiny change of probability model accuracy have a great effect on the calculation results, when the full data cannot be gained to establish probabilistic model, the probabilistic reliability method is not reliable.This paper presents the non-probabilistic reliability method of crawler crane structure based on interval analysis. This method only needs the boundary of the uncertain parameters, without the need for the distribution, thus which can make up for the deficiency of the probabilistic reliability and describe the reliability problem of the crawler crane boom structure accurately.This paper takes the crawler crane arm structure as the research object, The mechanics model of the crawler crane main, auxiliary arm structure is determined. The loads of arm structure are determined uncertain parameters, the non-probabilistic reliability of the strength, stiffness, overall stability of arm structure are studied respectively, the non-probabilistic reliability mathematical model of arm structure is determined. According to the different proportion of the arm structure reliability indicators, based on the analytic hierarchy process, the indicators of strength, stiffness, stability reliability are weighted, evaluated, the arm structure of the crawler crane is made the whole evaluation.The project example is analyzed using VC++6.0, some parameters are made parametric programming. In 35 tons crawler crane with main, auxiliary arm structure as an example, the non-probabilistic reliability of the stability, strength and stiffness of the arm structure are analyzed and calculated, the calculated values are considered as the indicators, the overall state of crawler crane arm structure is evaluated through the three indicators(stability, strength and stiffness). The working condition of the highest main arm and the maximum load for the crawler crane is evaluated, the evaluation results are compared with the actual situation, the conclusion can be drawn. The method can calculate the reliability and the overall security situation of arm structure with the different parameters conveniently and quickly. The amount of computation is reduced significantly. The non-probabilistic theory is well combined to the conventional algorithm of crane arm structure.