4100QB柴油机机体的形状优化及灵敏度分析

为了提高柴油机机体裙部刚度，该文以4100QB柴油机机体为研究对象，使用HyperWorks/Optistruct软件，采用形状优化的方法，进行了设计变量对响应变量的灵敏度分析，完成以提高机体裙部刚度为目标的优化设计。形状优化求解时选取了最大爆发压力工况、活塞侧向力最大工况、主轴承水平分力最大工况3种计算工况，设计变量为机体上与曲轴箱相关的12个结构尺寸，约束函数为机体的应变能、节点的水平位移、机体的质量，目标函数为使得机体裙部相关振型模态频率加权和最大。模拟计算结果显示机体的应变能和固有频率有不同程度的改善。该文的研究方法对于机体类零部件优化设计具有借鉴作用。

Shape optimization and sensitivity analysis for cylinder block of 4100QB diesel engine

By using the method of shape optimization, the rigidity of 4100QB diesel cylinder block was raised based on HyperWorks/Optistruct software, meanwhile the sensitivity analysis of the cylinder block was carried out to illustrate the design variable effects on response function. There were three kinds of forces in optimizing course applied in various load steps: maximum combustion pressure, maximum piston lateral force and maximum lateral force on the main bearing. The objective of optimization was the maximum sum of modal frequency related to the modal shape of crankcase. Twelve structure dimensions of the crankcase were adopted as design variables and the constraint functions were strain energy of the cylinder block, point displacement and weight of the cylinder block. The results showed that strain energy and frequency of the cylinder block had been improved at various degrees. This optimizing method provides certain reference function for the optimizing of other kinds of cylinder blocks.