铸铁构件固有频率与其残余应力关系的研究

Study on the Relation Between Residual Stress and Natural Frequency of Cast Iron Components

铸铁构件残余应力的评价过程一直相当繁琐．为找到一种简便无损的铸件残余应力评价新方法,以梁形铸件为研究对象,从理论计算和实际测试2个角度对铸件固有频率与其残余应力的关系进行了研究,得出了反映二者之间关系的数学模型．由这一模型可知,梁形铸铁构件残余应力与其固有频率的函数关系为抛物线,即铸件残余应力与其固有频率的平方成比例．利用其数学模型对一组梁形铸铁试件的残余应力和固有频率进行了理论计算,同时采用X射线应力测定法和实验模态分析方法测试它们的残余应力和固有频率,得出结果基本吻合．

It is a complex process to estimate residual stress of cast iron components. For the purpose of simplifying the evaluation method of residual stress of casting, the relation between residual stress and natural frequency of beam casting are studied from experimental and theoretical angles. The research reveals a mathematical model, which shows that the curve pattern of residual stress-natural frequency relation of beam casting is parabola, i.e. residual stress of beam casting is in proportion to double power of its natural frequency. We carry on theoretical calculation to a group of beam casting samples by means of this model. Simultaneously, we take advantages of X-ray diffraction stress measuring method and the experimental model analysis technology to measure natural frequency and residual stress of samples respectively. As a result, the calculation results are proved well to conform to experimental datum.