Reliability Analysis Of Truck Crane Boom

As one of the important operating equipment in infrastructure construction,truck cranes play a key role in our economic and social development.As the main force bearing component of the truck crane,the reliability of the boom is very crucial to the truck crane's safey.The safety factor method is still adopted in the existing design specifications of truck cranes,which ignores the influence of the random fluctuation of material characteristic parameters,geometric dimensions and loads on the safety performance of truck cranes,and it is difficult to measure the safety degree of the structure.So the design results are not completely reasonable.Therefore,this thesis takes the truck crane's boom as the main research object and studies its reliability with considering the influence of various random factors which exist in actual engineering practice.The main research contents are as follows:1)The variable decomposition method for reliability analysis of truck crane boom is given.By integrating the variable decomposition method and numerical integration method,the multi-dimensional integration expression used for calculating the origin moment function of performance function is converted into the sum of several single-dimensional or low-dimensional integration forms,and the probability density function of performance function is obtained by the maximum entropy principle.The proposed method has high accuracy and computational efficiency,which provides a calculation method for the reliability analysis of the boom.2)Reliability analysis of truck crane's boom is carried out.The equivalent beam model of truck crane boom is established and mechanical analysis is carried out.The performance functions of strength,stiffness,overall stability and local stability of the boom are derived.The origin moment of each performance function is obtained by variable decomposition method,and the probability density function of performance function is fitted based on Maximum Entropy Method.Taking 15 t truck crane's boom as an example,the reliability of boom structure under various failure mode is calculated,and the influence of various random factors on the reliability is analyzed,realizing the probability measurement of the boom's safety degree.3)Reliability analysis of truck crane's tip-over stability under deformed ground is finished.Based on the principle of moment balance,the stable moment and tipping moment of the truck crane on the deformed ground are deduced,the reliability calculation model of tip-over stability is established and solved by variable decomposition method.