Journal of Engineering Mechanics

The radial mapping version of the bounding surface plasticity formulation is applied to isotropic cohesive soils. While some aspects of this constitutive model have appeared in the past, a number of important novel features, including closed form analytical relations for certain loadings and the complete analytical formulation, are presented here for the first time. Based on the new aspects a much improved predictive capability is obtained, as shown by successful comparison with experimental data under different loading conditions. The analytical formulation and the significance of the different model constants are carefully investigated in order to have a better understanding of the simulated material response as obtained by numerical methods.

A rate‐independent elasto‐plastic bounding surface constitutive model applicable to anisotropic cohesive soils is presented. It is shown that the theory is capable of realistically accounting for the initial anisotropy and its subsequent evolution in a manner consistent with our current understanding of anisotropy. While retaining the capabilities of the bounding surface theory developed for isotropic cohesive soils, a more general hardening behavior, which includes rotational and shape‐hardening features, is introduced in this anisotropic theory in order to simulate the evolution of material anisotropy. By comparing the predictions with experimental data, the anisotropic theory is shown to provide satisfactory results under stress paths involving strong development of anisotropy.

Dynamic response of a long, continuous pipeline buried at a depth, h, below the free surface of the ground is analyzed. It is assumed that the pipe is disturbed by plane seismic waves traveling at an arbitrary angle to its axis. Thus, the problem is three dimensional. The pipe has been modeled as a cylindrical shell. Both the pipe and the surrounding ground are assumed elastic, isotropic, and homogeneous. The solutions of equations of elastodynamics governing the motions of both are obtained in terms of cylindrical eigenfunctions modified to satisfy the boundary conditions on the free surface of the ground. Numerical results are presented in the accompanying paper.

Using the analysis presented in the accompanying paper (Part I) numerical results showing the dynamic stresses (circumferential and axial) in buried pipe are presented. Incident plane seismic waves considered are: longitudinal (P), vertically (SV), and horizontally (SH) polarized shear, and Rayleigh (R) waves. Results show significant dependence on depth of embedment, properties of the surrounding ground, and frequency and wavelength of the incident wave.

Wind‐induced dynamic behavior of a silo‐like, thin circular cylindrical shell is studied to establish a rational analytical method. The ovalling oscillations are measured with elastic cylinders in a wind tunnel. It is shown that the ovalling characteristics in a smooth flow are quite different from those observed in a turbulent flow. Measurements of the time‐space correlations of the pressure fluctuations reveal that the pressure field on the cylinder surface has a convective nature in the smooth flow, while it is considerably random in the turbulent flow. On the basis of the expermental results, the dynamic response of elastic cylinders is analyzed by using a statistical method. As for the overall trend, the predicted results agree well with the experimental observations. Furthermore, the analytical results suggest that the dynamic response is strongly affected by the convection velocity of the pressure field; this is also consistent with the experimental results.

The dynamic impedance functions for a rigid hemispherical foundation embedded in a uniform viscoelastic half‐space are obtained by an integral equation approach. Numerical values for the vertical, torsional, horizontal, coupling, and rocking impedance functions for a wide range of frequencies are presented. Comparisons with results obtained by other methods, including finite element models, wave function expansions and other boundary integral formulations, are discussed.

A finite strip method is developed for the analysis of continuous elastic plate systems. This approach incorporates the effect of support element stiffness and mass in a direct manner. The stiffness and mass contributions of the support elements are derived and given as strip matrices. These matrices add directly with the plate strip matrices at the element level. This summation constitutes a substructure termed a compound strip. This methodology may be readily incorporated into existing finite strip programs based on lower order elements. The theory is illustrated with an example analysis. The compound strip methodology compares favorably with the finite element method for frequency and mode shape.