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Experimental analysis of ferroelectric composites with a viscoelastic and dielectric reaxation matrix is carried out, and the electromechanical coupling behavior of the ferroelectric composites is calculated by means of the constitutice model proposed in this paper. Comparisons between the experimental results and the calculations show that the constitutive model can reflect the electromechanical coupling behavior of the ferroelectric composites. The analysis indicates that the effect of viscoelasticity and dielectric relaxation of the matrix on the electromechanical coupling behavior of ferroelectric composites cannot be neglected.

The stress analysis based on the theory of a thin shell is carried out for cylindrical shells with normally intersecting nozzles subjected to external moment loads on the ends of shells with a large diameter ratio(ρ 0 «0. 8). Instead of the Donnell shallow shell equation, the modified Morley equation, which is applicable toρ 0(R/T)1/2 »1, is used for the analysis of the shell with cutout. The solution in terms of displacement function for the nozzle with a nonplanar end is based on the Goldenveizer equation. The boundary forces and displacements at the intersection are all transformed from Gaussian coordinates (α, β) on the shell, or Gaussian coordinates (ζ, θ) on the nozzle into three-di-mensional cylindrical coordinates(ρ,θ, z). Their expressions on the intersecting curve are periodic functions ofθ and expanded in Fourier series. Every harmonic of Fourier coefficients of boundary forces and displacements are obtained by numerical quadrature. The results obtained are in agreement with those from the three-dimensional finite element method and experiments.

The present paper is concerned with the limit analysis of a thin cylindrical shell with hemispherical ends under internal pressure. Seven cases of collapse mechanisms for various geometry parameters are examined and the complete solution for each mechanism is obtained. The range of validity for each mechanism is also determined. It is proved that the solutions obtained from the seven mechanisms are complete.