摘要
为提高农机底盘关键零部件的可靠性,以4LZ-2稻麦联合收割机经改进后的驱动桥壳为研究对象,分别对驱动桥壳在最大垂向力、最大牵引力、最大制动力和最大侧向力4种典型工况下的强度和刚度可靠性进行了研究。基于ANSYS/APDL参数化设计语言建立驱动桥壳参数化模型,并依据可靠性干涉原理建立了驱动桥壳强度和刚度可靠性模型;将驱动桥壳的几何尺寸、载荷、材料强度等设为服从正态分布和均匀分布的随机变量,运用ANSYS概率设计模块和Monte-Carlo抽样法,对驱动桥壳的可靠性进行仿真分析,得出驱动桥壳在最大垂向力和最大侧向力2个工况下可靠行较差;通过参数灵敏度分析可知,当动载荷系数、满载轴荷和最大牵引力增大时,驱动桥壳趋于失效状态;当材料强度、左右板簧座间距和半轴套管大端直径增大时,驱动桥壳将趋于更加可靠。该研究方法与结果可为农机底盘驱动桥壳等关键零件的精益设计提供理论指导。
The reliability of a kind of drive axle housing was studied mainly in this study. The three-dimensional parametric model of the drive axle housing was established by using parametric design language of ANSYS （APDL）, and then the strength and stiffness reliability were built on the basis of the interference principle of reliability. The reliability analysis of drive axle housing was discussed under the following four typical working conditions： maximum vertical force, maximum tractive force, maximum braking force and maximum lateral force. The strength and stiffness reliability under the conditions of different working were analyzed respectively. Considering the randomness and uncertainty of the design parameters, the geometry size, load and material strength were set into normal distribution （GAUS in ANSYS） and uniform distribution （UNIF in ANSYS）. The Monte-Carlo sample method and stochastic finite element method were adopted to carry out the reliability analysis. A simulation cycle was equivalent to a sampling test, and the longer the simulation cycle lasted, the larger the sampling number was, and the better accurate the simulation result was. With the simulation cycle time of the four conditions of 488, 649, 928 and 488 respectively, the mean and standard deviation of equivalent stress sampling and deformation sampling were stabilized. The results mainly included the static analysis, the reliability analysis and the sensitivity analysis. Firstly, the equivalent stress contour and deformation contour of the drive axle housing under these four conditions were shown. Secondly, the strength reliability and stiffness reliability was also obtained. The strength reliability of all conditions and the stiffness reliability of maximum vertical force condition were more than 90%, and the stiffness reliability of the other three conditions was 100%. The results also showed that the strength reliability of the maximum lateral force condition and the stiffness reliability of maximum vertical force condition were the worst. The maximum vertical force condition and the maximum lateral force condition should be given priority consideration in the design process. Finally, through the sensitivity analysis results, the influence rules of design parameters on the reliability of the drive axle housing were obtained. The most important parameters included dynamic load coefficient K1, maximum vertical force of full load in the static state F, maximum tractive force P, material strength S and geometry size L, L1 and D4. When the parameters of K1, F and P became larger, the reliability of the drive axle housing would turn worse. On the contrary, the reliability became higher with the increasing of S, L1 and D4. Additionally, the effect of the parameter L （half of wheel track） on the reliability of the drive axle housing was more complicated. The reliability became better with the increasing L under the maximum vertical force condition and became worse under the other three working conditions. Therefore, the change of L should be strictly controlled in the design process. The research method and the analysis results can provide a theoretical guidance for the reliability design of key parts such as drive axle housing of the agricultural machinery chassis.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2013年第2期37-44,I0002,I0003,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
"十二五"国家科技支撑计划项目(2011BAD20B01)
关键词
农业机械
可靠性分析
灵敏度分析
驱动桥壳
概率设计
agricultural machinery, reliability analysis, sensitivity analysis, drive axle housing, probability design
