Structural Analysis And Optimization Of The Large-scale Wide Paver Screed System

With the rapid development of highway construction in China,the construction puts forward higher requirements on the quantity and quality of the road construction machinery.In this context,as one of the key equipments of road construction machinery,asphalt concrete paver has been rapidly developed.Screed is the core working device of the paver,whose main function is to preload,shape and iron of the paving medium.Therefore,the pros and cons of the static and dynamic characteristics of its structure will directly affect the quality of paving pavement.But at present,the technology in the research field of large wide spreader screed falls behind relatively in China.The the domestic market has been occupied by the imported large wide paver.Based on the above background,the 12m mechanical assembly screed provided by a domestic company is taken as the object of study in this paper.The dynamic and static characteristics of the screed box structure are further studied,and a variety of different optimization design methods are used to optimize the structure.The main contents of the paper are as follows:(1)The finite element model of screed box structure with bolt joint is established,and the accuracy of finite element model is verified by modal test of screed two boxes.(2)The dynamic and static characteristics of the screed box structure are analyzed.From the results of the comprehensive analysis,it can be considered that two sections of 1.5 meters long section of the screed box are the weak links of the whole structure,which provides the reference for subsequent optimization design.(3)The multi-objective topology optimization design of the two sections of 1.5 meters long section of the screed box is carried out.The multi-objective optimization problem,which maximizes the static stiffness of single-mode and the first-order natural frequency,is transformed into a single-objective optimization problem by means of the eclectic programming method combined with the function function method.The multi-objective topology optimization model of two-box of the screed is established,and the structure of the box is improved according to the optimized result.The longitudinal bending deformation of two-box of the improved screed decreased by 6.58%,and the first order natural frequency increased by 4.39%.The dynamic and static characteristics were improved obviously.(4)Based on the agent model,the lightweight design of wo sections of 1.5 meters long section of the screed box is carried out and the agent model between the response of each box and the box size parameter is established.The mass of the box is taken as the objective function and the other responses is taken as the constraint condition.The particle swarm optimization algorithm is used for the lightweight design of it.The mass of optimized two-box of the screed is reduced by 37.94kg(6.59%),compared with the original design alternative.(5)The dynamic and static characteristics of the whole structure of the optimized screed box are analyzed and compared with the original model.The dynamic and static characteristics of the optimized model are improved obviously.In order to further suppress the thermal deformation of the whole structure,the orthogonal test method is used to optimize the combination of the tie rods,and the optimal combination method is obtained.