Numerical Example: Plate Structure

As a numerical example a plate structure of size 4/ by 2l (l = 1.25 m) with thickness t = 0.25 m is investigated (see Figure 3). Young’s modulus E = 30.0 GPa, Poisson’s ratio v = 0.16, correlation length lc = 1.0 m, coefficient of variation є = 0.1, mass density q = 2500 kg/m3, p(x, y) = 1.6 MPa.

It is assumed that a set of natural frequencies щ is measured (cf. Table 1) for one particular realization of the random field as shown in Figure 4. The unconditional mean and standard deviation of the vertical deflection under the given static load are shown in Figures 5 and 6, respectively. By including the measurements of the two lowest natural frequencies, the standard deviation of the deflection is considerably reduced as shown in Figure 7. As shown in Macke and Bucher (2000), the