基于响应面法全液压湿式驱动桥壳可靠性优化

为解决湿式驱动桥壳结构传统优化中的低效性和不确定性,提出了一种将响应面模型与可靠性相结合的优化设计方法。该方法从建立全液压湿式驱动桥壳有限元模型出发,结合拉丁方试验设计方案,利用最小二乘法构建驱动桥壳的二阶响应面近似模型。在此基础上,以驱动桥壳最大应力最小为优化目标,以驱动桥壳结构几何参数为设计变量,建立可靠性优化模型。对某驱动桥壳的优化结果表明,优化后的桥壳最大应力降低了10.91%,桥壳质量降低了10.93%,在满足相应强度要求的条件下有效降低桥壳的质量,达到可靠性设计的目的。     

Nonlinear buckling analysis of pre-stressed ring-stiffened circular cylindrical shells under external pressure

This paper is concerned with the nonlinear buckling behavior of pre-stressed ring-stiffened thin circular cylindrical shells under external pressure. According to the geometrical nonlinearity, governing equations are derived by incorporating initial stresses based on Donnell-type shell theory. The “smeared stiffeners” approach is used for ring stiffeners. The numerical analyses are conducted by Gelerkin’s method to obtain critical buckling loads of shells. This study shows effects of initial stresses on stability of shells. Moreover, effects of initial stresses on buckling modes of shells are discussed.     

贵州省新能源汽车产业发展现状及对策研究

本文立足贵州省新能源汽车产业发展现状,分析新能源汽车产业发展和示范推广中存在的问题,结合贵州省"十三五"战略性新兴产业发展规划,提出加快贵州省新能源汽车产业发展的三点对策与建议。即政府牵头,校企合作,突破核心技术;提升贵州省内骨干企业竞争力,创新市场推广模式;优化产业结构,完善零部件配套体系建设,以期实现全省汽车行业健康持续的发展。