柴油机曲轴与气缸体系统动力学仿真研究

利用有限元模态综合技术得到曲轴、飞轮及气缸体柔性体模型，运用雷诺油膜方程描述主轴承油膜的非线性特性，建立了曲轴组件与气缸体耦合多体动力学仿真模型，在ADAMS仿真平台上对模型进行了多柔性体动力学仿真分析.由仿真计算得到关于气缸体NVH（噪声、振动与平顺性）特性的载荷和位移边界条件，如活塞侧向拍击力、主轴承载荷、主轴承油膜最小厚度随曲轴转角曲线.在仿真环境下比较了采用柔性气缸体和刚性气缸体两种条件下曲轴的主轴颈轴心轨迹图，最后利用试验测量的气缸体表面节点振动数据验证了耦合系统动力学仿真结果的有效性.

Dynamic simulation research on diesel engine's cranktrain and block

By using the modal synthesis technique of finite element method(FEM), the components such as the engine block and crankshaft were reduced to flexible bodys for dynamics analysis.The coupled system of the engine cranktrain and block was set up in ADAMS.The Reynold's equation was used to describe the hydrodynamics characteristic of the mainbearing's lubrication oil-film.From the dynamics simulation results,the boundary conditions of the NVH(noise,vibration and harshness) characteristics such as the piston thrust,the mainbearing's load and the minimum oil-film thickness etc.were obtained.After getting the orbits of the main-journal center,the differences between the engine block building with the flexible body and the rigid body were compared.Consequently,using the test data of the engine block surface's vibration validated the results of the coupled system dynamics simulation.