CORRELATIONS BETWEEN DYNAMIC STRAIN AND VELOCITY IN RANDOMLY EXCITED PLATES AND CYLINDRICAL SHELLS WITH CLAMPED BOUNDARIES

Relationships for the correlation of dynamic strain and velocity in randomly vibrating plates and cylindrical shells are derived. These relationships are of interest for practical predictions of maximum dynamic strain from simple vibrational velocity measurements obtained using accelerometers, and are based on (1) farfield relationships between the propagating wave components of dynamic strain and velocity, (2) factors for the effects of evanescent waves, and (3) the correlation of dynamic strain and velocity spatial maxima in narrow frequency bands. Spatial distributions of dynamic bending strain and velocity are also presented depicting the propagating wave component of the response, correlations between dynamic strain and velocity, evanescent wave effects and dynamic stress concentration at clamped boundaries. Experimental results are presented supporting the use of derived relationships for the measurement of maximum dynamic strain. The derived relationships apply equally to narrowband and broadband-excited systems by avoiding the need to satisfy diffuse wave conditions.