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全地形四轮车(ATV)车架挂发动机的结构动态特性好坏很大程度上决定其整车振动舒适性,但目前没有一种简单、有效且通用的ATV车架挂发动机有限元建模方法。通过对多款ATV结构动态特性的计算和实验分析,提出了分析ATV车架挂发动机结构动态特性的一种简单且具有通用性的有限元建模方法——把发动机简化为具有质量和转动惯量的0维质量单元,在车架上发动机的悬挂位置创建多点约束单元,然后通过MSC.Nastran中的beam单元将多点约束单元与集中质量单元连接起来,以模拟车架与发动机的连接方式。考虑到试验测量发动机惯性参数时受其内部运动部件及机油量等的影响,分析了发动机转动惯量在实测数据的基础上同时减少和增加5%时,对所提出的有限元建模方法分析车架挂发动机动态特性的影响。结果表明所提出的建模方法仍然可以保证对车架挂发动机结构动特性的分析在工程参考误差范围内。该建模方法对于ATV的设计和开发具有简易性和通用性,可在产品设计和改型阶段就能了解车架挂发动机的结构振动特性,提高了产品的开发能力,节约了大量的时间和成本。
At present, there is not a simple, effective and universal ATV frame-mounted engine finite element model for modeling the dynamic characteristics of ATV frame-mounted engines. method. Based on the calculation and experimental analysis of the dynamic characteristics of a variety of ATV structures, a simple and universal finite element modeling method for analyzing the dynamic characteristics of the ATV frame-mounted engine structure is proposed - the engine is simplified to have the mass and moment of inertia Of the 0-D mass unit, create a multi-point restraint unit on the frame of the engine at the suspension position, and then connect the multi-point restraint unit to the concentrated mass unit through the beam unit in MSC.Nastran to simulate the connection between the frame and the engine . Taking into account the experimental inertia parameters measured by the internal moving parts and the amount of oil and other effects, the analysis of the engine moment of inertia based on the measured data while reducing and increasing 5% of the proposed finite element modeling method to analyze the car Effect of rack-mounted engine dynamics. The results show that the proposed modeling method can still guarantee the analysis of the dynamic characteristics of the frame-mounted engine structure within the project reference error. The modeling method is simple and versatile for the design and development of ATV. It can understand the structural vibration characteristics of the frame-mounted engine during the product design and remodeling stages, improve the product development capability, save a lot of time and cost.