基于逆向建模和光纤光栅测量的风扇叶片的应力分析

Stress Analysis of Electric Fan Blade Based on Backward Model Building and the Fiber-Optic Grating Measurement

通过对研究对象风扇叶片进行三维坐标测量并将其测量结果导入PRO/E 3.0中进行CAD逆向建模,便可还原叶片模型.将所得到的叶片模型导入有限元分析软件ANSYS,定义好材料属性和边界条件进行应力应变分析,从而得到叶片在旋转离心作用力和流体载荷下的变形和应力分布.为验证对比,在叶片4个不同目标位置贴上光纤传感器进行应力应变测量.测量结果表明光纤测量目标位置应力应变结果和有限元分析数据基本一致.从而验证了光栅测量方法的可行性和逆向建摸的可靠性,并依此确定了叶片的危险部位即位于叶片根部弯曲较大的边缘地带,为叶片的进一步优化设计及其在线监测提供了理论依据.

By measuring the three-dimensional coordinates of fan blade and backward building its model by CAD software with the measuring data, the fan blade model was regenerated. And then the deformation and strain of fan blade under the centrifugal acting force of revolution and fluid loads were obtained by analyzing the model with the finite element analysis software. Experimentally the target locations of the four different were affixed with fiber-optic grating sensors for theirs＇ stress-strain measurements. The experimental results were consistent with the data from the model, which verified the feasibility of the grating measuring method and the reliability of backward building the model by the CAD software. At the same time, it was ascertained that the roots of fan blade are the weak parts. The study can provide theoretical basis for the optimal design of a fan blade and the online monitor.