高强化机车柴油机组合活塞热弹性接触分析

Thermo-elastic Contact Analysis of the Composite Piston in Highly-Uprated Locomotive Diesel Engines

零件之间的接触与配合问题在内燃机零件强度和可靠性设计中是一个迫切需要解决的重要问题。本文以机车柴油机钢顶铝裙组合活塞为对象,建立组合活塞钢顶 铝裙 连接螺栓-活塞销的四体接触计算模型。采用该模型对组合活塞在预紧工况、最大惯性力工况、最大气体爆发压力工况下进行了三维热弹性接触有限元分析,根据 Von Mises屈服条件对活塞疲劳强度进行分析,以确定组合活塞的受力薄弱环节,从而改进组合活塞的结构设计,为改进其设计工艺和提高其工作可靠性提供理论依据。

The contact and fitting between the engine parts are exigent problems in the design of intensity and reliability. This paper introduced a four-body contact model of steel crown-the nodular cast-iron skirt-piston pin-connecting bolt for the steel-crown aluminum-skirt composite piston of locomotive diesel engines. In the contact calculation model, the 3D thermo-elastic contact finite element analysis was carried out under the load case of the assemble forces, the maximum inertia force and the maximum gas force. And the fatigue strength of composite piston was analyzed according to Von-Mises yield condition. The weakest district of the composite piston under forces was found out, which can provide support for design and reliability of the composite piston.