快速精确获取设计中农业机械模态模型的方法

在农业机械的设计过程中，为了快速获得产品整机的模态参数，该文以某小型农业作业机为例，探讨了采用NASTRAN求解的方法获取设计结构的模态模型；采用LMS Test.Lab试验模态分析的方法获取复杂外购件和通用件的模态模型，用自由界面模态综合的方法将通过前述方法获得的各结构模态在LMS Virtual.Lab中综合，最终获取整机模态模型的方法。试验证明采用该方法获得的主要固有频率最大误差小于5.5%，且振型基本吻合。采用该方法可以在小型农业机械的快速设计过程中，快速、准确获取整机模态参数，为在设计过程中研究产品的动态特性和进行结构优化提供了数据支撑，具有重要的工程应用价值。

Fast and accurate obtaining modal model for designing agricultural machinery

Taking a certain small agricultural machine as an example for obtaining modal parameters of the whole machine during the design process of agricultural machinery. Firstly, the structural modal model for designing was studied by using NASTRAN. And then, the modal model of some complex outsourcing and general parts were studied by experimental analysis using LMS Test.Lab. Finally, the modal model of the whole machine had been obtained within LMS Virtual.Lab using free interface modal synthesis method which integrated the acquired modes of the structures. The experimental results of presented method showed that the maximum errors of the main natural frequencies were less than 5.5%, and the mode shapes were also satisfied with the experimental results. Generally, the proposed method can be applied in the fast and accurate design of small agricultural machinery for acquiring the structural modal parameters. Moreover, it also provides data support for the study of dynamic behaviors of product structure and optimizes the configuration of the design process. The proposed method clearly shows its important engineering role in agricultural machine design.