scholarly journals Diffusion Through a Network of Compartments Separated by Partially-Transmitting Boundaries

2019 ◽  
Vol 7 ◽  
Author(s):  
Gorka Muñoz-Gil ◽  
Miguel Angel Garcia-March ◽  
Carlo Manzo ◽  
Alessio Celi ◽  
Maciej Lewenstein
Keyword(s):  
Transmitting Boundaries

scholarly journals Viscoelastic Boundary Conditions for Multiple Excitation Sources in the Time Domain

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Chen Xia ◽  
Chengzhi Qi ◽  
Xiaozhao Li
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Time Domain ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Seismic Loads ◽  
Element Analysis ◽  
Artificial Boundaries ◽  
The Time Domain ◽  
Transmitting Boundaries

Transmitting boundaries are important for modeling the wave propagation in the finite element analysis of dynamic foundation problems. In this study, viscoelastic boundaries for multiple seismic waves or excitations sources were derived for two-dimensional and three-dimensional conditions in the time domain, which were proved to be solid by finite element models. Then, the method for equivalent forces’ input of seismic waves was also described when the proposed artificial boundaries were applied. Comparisons between numerical calculations and analytical results validate this seismic excitation input method. The seismic response of subway station under different seismic loads input methods indicates that asymmetric input seismic loads would cause different deformations from the symmetric input seismic loads, and whether it would increase or decrease the seismic response depends on the parameters of the specific structure and surrounding soil.

scholarly journals Time Domain Implementation of Transmitting Boundaries in ABAQUS for Discrete Soil-structure Interaction Systems

2020 ◽  
Vol 5 (3) ◽  
pp. 447-462
Author(s):  
J. Rama Raju Patchamatla ◽  
P. K. Emani
Keyword(s):  
Time Domain ◽  
Soil Structure ◽  
Seismic Waves ◽  
Seismic Analysis ◽  
Discrete Models ◽  
Soil Structure Interaction ◽  
Finite Domain ◽  
Infinite Domains ◽  
Structure Interaction ◽  
Transmitting Boundaries

Soil-structure-interaction (SSI) analyses are essential to evaluate the seismic performance of important structures before finalizing their structural design. SSI under seismic condition involves much more complex interaction with soil compared to the dynamic loads having source on the structure. Seismic SSI analysis requires due consideration of site-specific and structure-specific properties to estimate the actual ground motion (scattered motion) experienced at the base of the structure, and subsequently the effects of the scattered motion on the structure. Most challenging aspect of seismic SSI analysis is to implement transmitting boundaries that absorb the artificial reflections of stress waves at the truncated interface of the finite and infinite domains, while allowing the seismic waves to enter the finite domain. In this paper, the time domain implementation of seismic analysis of a soil-structure system is presented using classical discrete models of structure and interactive force boundary conditions for soil. These models represent typical SSI systems- a single Degree of Freedom (DOF) of a spherical cavity with mass attached to its wall, a two DOF system consisting of a mass attached by a nonlinear spring to a semi-infinite rod on elastic foundation, and a three DOF system with additional DOFs for modelling the structural stiffness and damping. The convolution integral representing the force boundary condition on the truncated interface, is evaluated interactively using UAMP user-subroutine in ABAQUS and applied as concentrated forces at the interface (truncated interface) nodes of the bounded domain or generalized-structure domain. The verification problems presented in the paper show the satisfactory performance of the developed MATLAB code and ABAQUS implementation with FORTRAN user-subroutines. The classical phenomena associated with the dynamic soil-structure systems are discussed through the present work.

Nonlinear Amplification of Seismic Ground Motion by Alluvial Valley

2013 ◽  
Vol 438-439 ◽  
pp. 1572-1576
Author(s):  
Jian Wen Liang ◽  
Ming Liang Liu
Keyword(s):  
Dynamic Analysis ◽  
Ground Motion ◽  
Linear Method ◽  
Alluvial Valley ◽  
Soil Layers ◽  
Seismic Ground Motion ◽  
Soil Nonlinearity ◽  
Nonlinear Amplification ◽  
Transmitting Boundaries ◽  
Equivalent Linear Method

This paper studies nonlinear amplification of seismic ground motion by alluvial valley in layered sites. The equivalent linear method is used in dynamic analysis and transmitting boundaries are added at boundaries of the computation region. It is shown that, soil nonlinearity has significant effect on seismic ground motion around alluvial valley. The amplitudes in the case of linear alluvium and soil layers are the largest, those in the case of nonlinear alluvium and soil layers are the smallest, and those in the case of nonlinear alluvium and linear soil layers fall in between. The periods in the case of nonlinear alluvium and soil layers are the longest, those in the case of nonlinear alluvium and soil layers and those in the case of linear alluvium and linear soil layers are almost the same.

Transmitting boundaries: A closed-form comparison

1981 ◽  
Vol 71 (1) ◽  
pp. 143-159
Author(s):  
Eduardo Kausel ◽  
John L. Tassoulas
Keyword(s):  
Wave Propagation ◽  
Numerical Analysis ◽  
Closed Form ◽  
Neumann Boundary ◽  
Line Load ◽  
Problem Of Time ◽  
Time Harmonic ◽  
Infinite Extent ◽  
Transmitting Boundaries ◽  
Absorption Characteristics

abstract Several transmitting boundaries which have been proposed for the numerical analysis of problems of wave propagation in continua of infinite extent are reviewed. They are grouped into three broad classes: (1) elementary boundaries (Dirichlet or Neumann boundary conditions); (2) highly absorbing local boundaries; and (3) consistent transmitting boundaries. A closed-form comparison for the problem of time-harmonic antiplane line load on a stratum shows that elementary boundaries produce strong reflections, local boundaries have good absorption characteristics, and consistent transmitting boundaries are perfect absorbers.

Sign in / Sign up

Export Citation Format

Share Document