球化率音频检测的激励点有限元优化研究

Research for exciting position in spheroidization rate audio detection based on finite element optimization

在球化率音频检测过程中,激励点的选取直接影响到各阶模态频率响应的值,特别对于相邻的模态频率响应,还会导致测量结果的差异。为提取关注的模态频率,抑制非关注的模态频率,提出了一种基于有限元的激励点优化方法。以汽车零部件飞轮为例,通过ANSYS对球墨铸铁待测件进行模态分析,结合各阶振型特点、固有频率以及模态激励理论,确定优化激励点,通过MATLAB GUI程序对激励点的音频信号进行分析验证。实验结果表明,该方法可对此飞轮结构所关注的模态振型做到有效激励,验证了相邻模态频率响应与激励点的选择有着密切关系,并可通过激励点的调整,有效区分相邻频率的模态振型。

In the process of spheroidization audio detection, the selection of exciting position directly affects the amplitude of the modal frequency response of each order directly. For similar modal frequency responses, it is likely to affect the measurement results. In order to extract the modal frequencies of interest and suppress the modal frequencies of no-concern, a finite element-based optimization method for exciting position is proposed. Taking the car’s part flywheel as an example, modal analysis is performed on the spheroidal graphite cast iron test piece through ANSYS, combining the characteristics of each order mode, natural frequencies and modal excitation theory to determine the optimal excitation point, and the audio signal of the exciting positions is analyzed by MATLAB GUI verification. The experimental results show that this method can effectively stimulate the modal shapes required for the observation of the flywheel structure. It is verified that the close modal frequency response is closely related to the choice of the exciting position. Effectively distinguishing modal shapes of similar frequencies has strong practicability.