全地形四轮车结构振动特性实验与仿真

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。

Testing and Simulation on Dynamic Characteristics of ATV Body

ATV(All-Terrain Vehicle) structural dynamic characteristics affect greatly its vibration performance and riding comfort,but a simple,common and effective finite-element modeling method for ATV body with engine is rare.Based on simulation and tests for ATV bodies,a simple and common finite-element modeling method was proposed simplifying engine as a 0-dimensional mass element with weight and rotary inertia,creating MPC at suspending point of engine,and connecting MPC with 0-dimensional mass element through beam element in MSC.PATRAN was established to analyze body dynamic characteristics.Considering the influences of engine inner configuration and oil quantity,body dynamic characteristics were analyzed after engine rotary inertia being reduced or increased by 5%.The results show that the new method is valid and engineering error range limit is normal and allowed.Helpful to identifying the dynamic characteristics of ATV body in the process of design and retrofit,the simple and common method could improve the capability of development and save much cost which can be applied in developing and design of ATV.