Full-Field Random Bending Strain Measurement of a Plate From Vibration Measurement

Optical measurement of the dynamic strain field of a fan blade using a 3D scanning vibrometer

“…According to small deformation theory, the strain components in a plate due to bending are given by [9,13] e xx ðx,y,tÞ ¼ Àz @ 2 wðx,y,tÞ @x 2 e xy ðx,y,tÞ ¼ Àz @ 2 wðx,y,tÞ @x@y e yy ðx,y,tÞ ¼ Àz…”

“…This technique has been in use since the 1990s [1,[6][7][8][9], but it should be noted that in these publications only the bending deformation (and strain) could be measured since they were restricted to using single beam Laser Doppler Vibrometry. Moreover, due to poor transducer quality, early applications of this technique required extensive spatial filtering to improve the quality of the (bending) strain estimates, at the expense of the spatial resolution.…”

Optimization Acceleration Integral Method Based on Power Spectrum Estimation

“…The Welch method belongs to the non-parametric spectral estimation method, which is characterized by two aspects: (1). It allows subsequences ( ) i a n to overlap each other;(2) It can be windowed for each subsequence, which can generate average correction period graph.…”

“…However, the presence of DC components in the acquisition signal, temperature drift, unstable sensor low-frequency performance, and ambient environment interference will all can generate trending items in the signal [1][2][3] . The trend items become more obvious when integrating to speed and displacement, which causes the signal to have a baseline drift, more than this, the displacement signal obtained by the integral will be seriously distorted.…”

The effect of random point excitation on the vibration level of plates

“…Kim and Chung ( 1995) proposed a method to determine optimal reference spectrum in random vibration control problems. Xu and Miles (1996) estimated the power spectral densities of the random bending strains at all points on the structures by the numerical differentiation of cross spectral densities of the vibration measured by two transducers. Han, Bernhard, and Mongeau (1997) The modes also satisfy the orthogonality condition lJf iP=2 sin ( 1:: )si n ( PJ:…”