Journal of Advanced Materials in Engineering (Esteghlal)

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A solution technique for the dynamic analysis of asymmetric base-isolated buildings, subject to earthquake ground motion, is presented. To develop the formulation, a yield surface as a function of both shear force and torsion moment of the sliding surface with rigid perfectly plastic behavior is constituted. To achieve the objective, the yield stress is defined by the friction coefficient through a simple relation. Having introduced the mathematical model of the yield surface, the simple conditions of being at the onset of sliding and nonsliding phases of motion are given. Based on the elaborated model, the earthquake dynamic analysis of a 3-D structure is performed. The results are in good agreement with those obtained by the finite-element modeling of the surface.

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This paper may be regarded as a new numerical method for the analysis of triangular thin plates using the natural area coordinates. Previous studies on the solution of triangular plates with different boundary conditions are mostly based on the Rayleigh-Ritz principle which is performed in the Cartesian coordinates. Consequently, manipulation of the geometry and numerical calculation of the integrals are time consuming and tedious. In this paper a new approach is developed to analyze triangular plates by the Ritz method, using interpolation functions in the area coordinates. The geometry is presented in a natural way by mapping a parent triangle and the integrals are evaluated analytically. In this approach, the convergence is always assured due to the completeness of interpolating polynomials. Several examples are presented and the results are compared with other available data.

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