Research on Estimation of Frequency Response Function

Based on an investigation of existing methods for estimating fre- quency response functions（FRF）at home and abroad,two methods are ad- vanced.The one,denoted as H₁₂,avoids underestimates at resonances and overestimates at antiresonances,while the other,denoted as H_F,regards the noise ratio of output to input as varying with the frequency.Finally,a soft- ware for estimating frequency response functions is introduced.A modal test for a steel plate excited with a random signal is made,and frequency response function estimates are made,making use of the above software.The test re- sults conform well with the theoretical analysis.