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Hygrothermal effects on free vibration of woven fiber glass/epoxy laminated composite cylindrical shallow shells are investigated both numerically and experimentally. In the present finite element analysis a composite doubly curved shell model based on first order shear deformation theory (FSDT) is used for free vibration of cylindrical shell panels in hygrothermal environment. B&K FFT analyzer is used to determine the natural frequencies of vibration experimentally by conducting non-destructive testing. The effects of curvature ratios, lamination sequences and boundary conditions on natural frequencies of vibration under hygrothermal loading are investigated. The frequency of vibration decreases with increase of temperature and moisture. [ABSTRACT FROM AUTHOR]

The present computational study investigates on stochastic natural frequency analyses of laminated composite curved panels with cutout based on support vector regression (SVR) model. The SVR based uncertainty quantification (UQ) algorithm in conjunction with Latin hypercube sampling is developed to achieve computational efficiency. The convergence of the present algorithm for laminated composite curved panels with cutout is validated with original finite element (FE) analysis along with traditional Monte Carlo simulation (MCS). The variations of input parameters (both individual and combined cases) are studied to portray their relative effect on the output quantity of interest. The performance of the SVR based uncertainty quantification is found to be satisfactory in the domain of input variables in dealing low and high dimensional spaces. The layer-wise variability of geometric and material properties are included considering the effect of twist angle, cutout sizes and geometries (such as cylindrical, spherical, hyperbolic paraboloid and plate). The sensitivities of input parameters in terms of coefficient of variation are enumerated to project the relative importance of different random inputs on natural frequencies. Subsequently, the noise induced effects on SVR based computational algorithm are presented to map the inevitable variability in practical field of applications. [ABSTRACT FROM AUTHOR]