RESUMEN En este estudio se presenta un modelo parejo dinámico de los elementos finitos para la simulación numérica del nivel de respuesta de las capas de una cuesta arenosa saturada objeto de una carga cíclica. Este mecanismo utiliza un modelo constitutivo de plasticidad de dos superficies en estado crítico para simular el comportamiento cíclico de los suelos arenosos. Además, se implementó una función de permeabilidad variable recientemente propuesta en el modelo numérico para reflejar los efectos de estas variaciones durante el fenómeno de licuefacción. El modelo numérico ha sido validado al simular varias pruebas bien documentadas de centrifugación geotécnica con diferentes densidades relativas de arena, línea de tiempo de aceleración base, e inclinación superficial de la capa arenosa. Los resultados obtenidos confirman que el modelo desarrollado es capaz de simular el comportamiento de las capas arenosas bajo cargas cíclicas en condiciones planas y de ligeramente empinadas.

ABSTRACT In this study, a fully coupled dynamic finite element model was employed for numerical simulation of the response of level to gently sloping saturated sand layers subjected to cyclic loading. This model utilized a critical state two-surface-plasticity constitutive model to simulate the cyclic behavior of sandy soil. Moreover, a recently proposed variable permeability function was implemented in the numerical model to reflect the effects of soil permeability variations during the liquefaction phenomenon. The numerical model was validated by simulating a number of well-documented geotechnical centrifuge tests with different relative density of sand, base acceleration time history, and surface slope of the sand layer. The obtained results confirmed that the developed model was capable of simulating the behavior of saturated sand under cyclic loading for both level and gently sloping conditions.

The present work introduces the boundary element method applied to the bending analysis of functionally graded plates. It is assumed that material properties are graded through the thickness direction of the plate according to a power law distribution. The neutral surface position for such plate is determined and the classical plate theory based on the exact neutral surface position is employed to extract the equilibrium equations. A direct approach based on the Green's identity is used to formulate boundary element method. By introducing a novel approach, domain integrals which arise from distributed transverse loads are transformed into boundary integrals. In case studies, three geometrical shapes including, rectangular, circular and elliptic for functionally graded plates with/without hole are considered. Comparative studies are first carried out to evaluate the sufficiency of the proposed method for bending analysis of isotropic and functionally graded plates subjected to the transverse loads. Then, a series parametric study is performed to examine the influences of the power of functionally graded material, boundary conditions and geometrical parameters on the deformation and stress of functionally graded plates.