针对发动机缸体结构复杂,工作过程中受到多种交变激振力作用的特点,建立了较详细的缸体瞬态强度分析有限元模型,模拟了缸体在发动机工作过程中的动态强度变化历程。得出:缸体与缸盖及变速器相连的紧固螺栓孔周围的整体应力水平较高,但随发动机工作负荷变化的波动量较小;缸体主轴承座周围动态应力和变形成分较高,且随发动机工作负荷变化的波动量较大;而缸体两侧壁的动态变形和应力与静态变形和应力水平较低。研究表明:在建模时考虑活塞和曲轴对缸体的接触作用,合理简化缸体结构,准确深入揭示工作过程中缸体的动态强度随时间的变化,为缸体动态结构强度设计提供可靠依据。 Aiming at the characteristics of complicated cylinder block structure and multiple alternating excitation forces during operation, a more detailed finite element model of transient strength analysis of cylinder block was established to simulate the change of dynamic strength of cylinder block during engine operation course. It is concluded that the overall stress level around the fastening bolt hole connecting the cylinder block with the cylinder head and the transmission is relatively high, but the fluctuation with the variation of the engine working load is small. The dynamic stress and deformation components around the main bearing of the cylinder block are higher, And fluctuates with the change of engine working load, and the dynamic deformation, stress, static deformation and stress of the two side walls of the cylinder are lower. The research shows that the contact between the piston and the crankshaft on the cylinder body is taken into account during the modeling, the cylinder structure is reasonably simplified, and the dynamic strength of the cylinder during the working process is accurately and in-depth revealed with time, thus providing a reliable basis for the dynamic structural strength design of the cylinder body .