柴油机机体模态分析与结构改进

为降低机体的表面结构振动和噪声辐射,采用ANSYS有限元分析软件建立了495型柴油机机体的有限元模型,对其进行自由模态分析,并对机体进行了试验模态分析。通过有限元结果和试验结果比较,验证了计算模型的准确性。根据模态分析结果,得出机体的固有振动特性。在该模型的基础上,增加了梯形加强板结构,使其固定于机体油底壳法兰底部。计算结果表明,铝制加强板能提高机体裙部刚度,抑制机体裙部的开合振动,有效地提高机体的固有频率。

Modal Analysis and Structural Improvement for Cylinder Block of Diesel Engine

In this paper,in order to reduce vibration and noise radiation of the cylinder block surface,the finite element model of cylinder block of a 495-type diesel engine was established and its modal analysis was done by using ANSYS FEA software.Experimental modal analysis of the cylinder was carried out.Calculation results were compared with those from the experiments and model was proved to be effective.According to the modal analysis results,the inherent vibration characteristics of this cylinder block were obtained.Then,a ladder-shaped stiffener was fixed on the oil pan rail of the cylinder block.Calculation results showed that this aluminum stiffener can improve the stiffness and inhibit opening and closing vibration of the skirt section.And the natural frequency of the cylinder block was improved effectively.