Analysis And Optimization Of Dynamic Characteristics Of Truck Crane Based On Virtual Prototype Technology

In order to meet the needs of China’s infrastructure construction,truck cranes are widely used in practical engineering.During the operation,sudden falling off of crane hoisting weight and swaying of hoisting weight can easily have a serious impact on its part and the service life of the whole machine.Therefore,it is necessary to study the dynamics of the truck crane.Traditional dynamics analysis methods are difficult to calculate and have low reliability,while virtual prototype technology has obvious advantages.It can obtain the parameters of the system motion law and dynamic characteristics in a short time,which can provide reference for the dynamics analysis of truck cranes or related construction machinery.Therefore,virtual prototype technology has been widely used.In this paper,based on the virtual prototype technology,a multi-body system dynamics analysis model is established for 25 t truck crane and its dynamic characteristics are studied,mainly including the following aspects of work:1.Aiming at the stability of the whole truck crane,a complex multi-rigid body system model with three different boom lengths is constructed using virtual prototype technology.The dynamics simulation is carried out and the vertical displacement curves of the four legs are obtained.The numerical simulation results show that the stability of the crane meets the design specification requirements.2.A rigid-flexible coupled system model of the truck crane is constructed for the force problems of key components.A finite element model of the key components is constructed and modal analysis is carried out to obtain the inherent frequencies and formations in order to provide a numerical basis for preventing resonance.The modal neutral file is imported into the multi-rigid body model for replacement,and rigid-flexible coupling dynamics simulation is carried out to calculate the stress value of each hazardous node of the key components,the corresponding node coordinates and the time of stress occurrence.The results of the rigid-flexible coupling numerical analysis show that the structural strength of the key components meets the requirements.3.For the problem that the hoisting weight may swing greatly,a parametric model of the wire rope is created.Considering the influence of the flexibility and length of the wire rope,four virtual prototype models with different rope lengths are constructed respectively,and the dynamics simulation of the emergency braking conditions during the steering table rotation is carried out to obtain the law of the wire rope length and the swing of the hoisting weight,which can provide a direct basis for the actual operation.4.Aiming at the position distribution of the three hinge points of the truck crane luffing mechanism,the optimization analysis is carried out,and the rationality of the optimization results is verified.With the driving force of the luffing cylinder in the luffing process as the objective function,the coordinates of the articulation points of the luffing mechanism are parameterized and used as design variables,and after the variable parameters are optimized,the maximum driving force of the cylinder in the luffing process is significantly reduced by9.96%.Through the analysis and optimization of the dynamic characteristics of the 25 t truck crane,the dynamic parameters of the truck crane under dangerous working conditions are obtained,pointing out the problems that need to be focused on when designing and using the truck crane,and a valuable reference is provided for the design and use of the same type of products.