Research On Structural And Performance Optimization Of High Horse-powered Bulldozer Working Device

Bulldozer has been widely used in urban and national defense construction,open-pit mining, construction of infrastructure set, roads and irrigation works andhydropower, etc. and it is mainly used for bulldozing soil, filling, digging canals andclean-up, etc. The working environment of high horse-powered bull-dozer is so badand the operating object more like ore or permafrost that the impact loads bulldozerand its blade bear are extremely large. Crossbar type working device in bulldozeremerges as the times require for its affordability of large impact loads. The operatingperformance of the bulldozer is determined by the size, position relation and intensity,stiffness of components in the blade. The eternal load the blade bears in normalcondition is very large, besides the blade is impacted by big external load duringworking, there are big changes of the internal force between components, so somecomponents or the links between them will be more easily broken.For cost or other factors, now there were relatively few experimental andreferenced data about the research object-crossbar type blade of bulldozer, so themethod combined with analysis of theory and simulation was applied in this paper.The dynamic and structural performances were researched and the optimization wasstudied by some relevant software on base of the analysis result. The main contents ofthis paper are as follows:1. This paper summarizes the development status of high horse-poweredbulldozer, study on structural optimization, its working device at home and abroad,and the advantages and disadvantages of the crossbar type working device aredesignated.2. As for theoretical analysis, first these parameters about scantling, junctionposition, blade cutting angle, blade tilt angle, the maximum lifting height and lowerheight controlled by lifting cylinder should be determined. Second, the theoretical andmotion characteristics in lifting and roll conditions were analyzed, horizontaloscillation and the length of lifting cylinder can get when the blade located at themaximum lifting height, lower height and the largest roll. In addition the stress ofcrossbar and launching bridge can get through the force analysis of the left endpointon the blade, and the mathematical model was preliminary established. 3. Then optimization scheme was determined preliminarily according to theoptimization objective, the optimization was a multidimensional nonlinearoptimization. The optimization algorithm of SQP, and optimization objective functionabout the smallest stress of crossbar and launching bridge, design variables of spacecoordinate of C, and constraint condition were set. The local optimal point wassearched in MATLAB optimization toolbox.4. As for simulation analysis, it mainly contained rigid-flexible coupled analysisof in the original and optimized model after optimization. The flex bodies of the twocomponents were established, and rigid-flexible coupled model can get after theywere imported to ADAMS. Then the parameters of simulation were set, at last thesimulation were performed after all these were set. The compared result between thetwo models: the optimization scheme is effective, the stress of the two componentsare decreased and can supply a reference for actual design, optimization andproduction.