Simplified Dynamic Finite-Element Analysis for Three-Dimensional Pile-Grouped-Raft-High-Rise Buildings

2008 ◽  
Vol 400-402 ◽  
pp. 613-619
Author(s):  
Hui Xiong ◽  
Shou Ping Shang ◽  
Liang Huang
Keyword(s):  
Finite Element ◽  
Structural Engineering ◽  
Computational Cost ◽  
Time History ◽  
Pile Group ◽  
Element Analysis ◽  
Structural Dynamic ◽  
Shell Elements ◽  
High Rise ◽  
Mass Spring

Combined with the respective advantages in S-R(Sway-Rocking) impedance concept and finite-element method, a simplified 3D structural dynamic FEM considering composite pile-group-soil effects is presented. The structural members including piles are modeled by spacial beam or shell elements, and raft-base is divided into thick-shell elements with its spring-dashpot boundary coefficient obtained by impedance backcalculated. The mass-spring elements for soil between piles are set to simulate vertical, horizontal pile-group effects by strata-equivalent approach. The soil beside composite body is separated into near-field and far-field parts. The former is modeled by nonlinear spring-dashpot elements based on Winkler’s hypothesis, while the latter is modeled by a series of linear mass-spring-dashpots. With the effects of boundary track forces and energy radiation, the presented model enables researchers to conduct the time-domain nonlinear analysis in a relatively simple manner which avoids sophisticated boundary method and solid-element mesh bringing with tremendous computational cost. The seismic effect on dynamic interaction of pile-soil-complicated structures would be efficiently annotated from two structural engineering and geotechnical engineering aspects and the numerical calculation effort would be drastically decreased too. The complete procedure is mainly performed using the parametric design language assembled in the Finite Element Code Ansys. With the dynamic analysis of foundation and superstructure for a pile-supported 15-storey building, the influence of the participant effect on structural dynamic response will be depicted by various dynamic parameters of pile-soil-raft foundation in detail. Not only do the results have an agreement with some conclusions drawn by the general interaction theory, but also certain of phenomena which would be disagree with that by general analysis is involved. Even with the finite-element meshes for 68 piles, the time-history analysis procedure for PGSS (Pile-Group-Soil-Superstructure) system and the qualitative evaluation with various SSI parameters can be also fulfilled efficiently and rapidly by presented means. These results may be of help to the designers to quickly assess the significance of interaction effect for the high-rise buildings resting on any type or layout of pile-group foundation.

scholarly journals Nonlinear Structural Dynamic Finite Element Analysis Using Ritz Vector Reduced Basis Method

1996 ◽  
Vol 3 (4) ◽  
pp. 259-268 ◽  
Author(s):  
M.S. Yao
Keyword(s):  
Finite Element ◽  
Equations Of Motion ◽  
Computational Cost ◽  
Finite Amplitude ◽  
Basis Vector ◽  
Reduced Basis ◽  
Ritz Vector ◽  
Element Analysis ◽  
Structural Dynamic ◽  
Nonlinear Equations Of Motion

The large number of unknown variables in a finite element idealization for dynamic structural analysis is represented by a very small number of generalized variables, each associating with a generalized Ritz vector known as a basis vector. The large system of equations of motion is thereby reduced to a very small set by this transformation and computational cost of the analysis can be greatly reduced. In this article nonlinear equations of motion and their transformation are formulated in detail. A convenient way of selection of the generalized basis vector and its limitations are described. Some illustrative examples are given to demonstrate the speed and validity of the method. The method, within its limitations, may be applied to dynamic problems where the response is global in nature with finite amplitude.

Finite Element Analysis of a Containment Vessel Structures Based on the Multi-Layer Shell Elements

2014 ◽  
Vol 711 ◽  
pp. 82-85
Author(s):  
You Jia Zhang
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Dynamic Test ◽  
Time History ◽  
Finite Model ◽  
Base Shear ◽  
Initial Stiffness ◽  
Element Analysis ◽  
Shell Elements ◽  
Containment Vessel

In order to research the prestressed concrete containment structure under Strong Earthquake, the multi-layer shell elements has been used to set up 3-d finite element model , time history and the static nonlinear analysis is carried out on the structure. Nonlinear finite element of a 1/10-scale PCCV model was analyzed and the dynamic characteristics of the model, the initial stiffness, the maximum base shear and the maximal displacement on the top of the cylinder had been calculated. Research show when ground motion reached 3g, tensile stress of concrete on wall and equipment at the bottom of the valve hole have exceeded 4MPa, but tensile stress of concrete on dome have less than 0.5MPa. The finite model calculated results are in good agreement with the results of previous papers of Pseudo dynamic test. It is concluded that this containment vessel has sufficient aseismic safety. It can provide a reference for seismic design.

On the Equivalence of Acoustic Impedance and Squeeze Film Impedance in Micromechanical Resonators

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Charanjeet Kaur Malhi ◽  
Rudra Pratap
Keyword(s):  
Finite Element ◽  
Acoustic Impedance ◽  
Entire Range ◽  
Microelectromechanical Systems ◽  
Acoustic Analysis ◽  
Computational Cost ◽  
Squeeze Film ◽  
Frequency Range ◽  
Element Analysis ◽  
Structural Dynamic

In this work, we address the issue of modeling squeeze film damping in nontrivial geometries that are not amenable to analytical solutions. The design and analysis of microelectromechanical systems (MEMS) resonators, especially those that use platelike two-dimensional structures, require structural dynamic response over the entire range of frequencies of interest. This response calculation typically involves the analysis of squeeze film effects and acoustic radiation losses. The acoustic analysis of vibrating plates is a very well understood problem that is routinely carried out using the equivalent electrical circuits that employ lumped parameters (LP) for acoustic impedance. Here, we present a method to use the same circuit with the same elements to account for the squeeze film effects as well by establishing an equivalence between the parameters of the two domains through a rescaled equivalent relationship between the acoustic impedance and the squeeze film impedance. Our analysis is based on a simple observation that the squeeze film impedance rescaled by a factor of jω, where ω is the frequency of oscillation, qualitatively mimics the acoustic impedance over a large frequency range. We present a method to curvefit the numerically simulated stiffness and damping coefficients which are obtained using finite element analysis (FEA) analysis. A significant advantage of the proposed method is that it is applicable to any trivial/nontrivial geometry. It requires very limited finite element method (FEM) runs within the frequency range of interest, hence reducing the computational cost, yet modeling the behavior in the entire range accurately. We demonstrate the method using one trivial and one nontrivial geometry.

scholarly journals Explicit Dynamic Finite Element Method for Failure with Smooth Fracture Energy Dissipations

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jeong-Hoon Song ◽  
Thomas Menouillard ◽  
Alireza Tabarraei
Keyword(s):  
Finite Element ◽  
Fracture Energy ◽  
Computational Cost ◽  
Quadrature Rule ◽  
Dynamic Failure ◽  
Structural Dynamic ◽  
Integration Schemes ◽  
Hourglass Control ◽  
Quadrilateral Finite Element ◽  
Explicit Dynamic

A numerical method for dynamic failure analysis through the phantom node method is further developed. A distinct feature of this method is the use of the phantom nodes with a newly developed correction force scheme. Through this improved approach, fracture energy can be smoothly dissipated during dynamic failure processes without emanating noisy artifact stress waves. This method is implemented to the standard 4-node quadrilateral finite element; a single quadrature rule is employed with an hourglass control scheme in order to decrease computational cost and circumvent difficulties associated with the subdomain integration schemes for cracked elements. The effectiveness and robustness of this method are demonstrated with several numerical examples. In these examples, we showed the effectiveness of the described correction force scheme along with the applicability of this method to an interesting class of structural dynamic failure problems.

Some new results and current challenges in the finite element analysis of shells

Acta Numerica ◽  
2001 ◽  
Vol 10 ◽  
pp. 215-250 ◽  
Author(s):  
Dominique Chapelle
Keyword(s):  
Finite Element ◽  
Shell Theory ◽  
Shell Structures ◽  
Engineering Practice ◽  
Element Analysis ◽  
Shell Elements ◽  
Shell Models ◽  
The Finite Element Analysis ◽  
Shell Finite Element ◽  
Mathematical Analyses

This article, a companion to the article by Philippe G. Ciarlet on the mathematical modelling of shells also in this issue of Acta Numerica, focuses on numerical issues raised by the analysis of shells.Finite element procedures are widely used in engineering practice to analyse the behaviour of shell structures. However, the concept of ‘shell finite element’ is still somewhat fuzzy, as it may correspond to very different ideas and techniques in various actual implementations. In particular, a significant distinction can be made between shell elements that are obtained via the discretization of shell models, and shell elements – such as the general shell elements – derived from 3D formulations using some kinematic assumptions, without the use of any shell theory. Our first objective in this paper is to give a unified perspective of these two families of shell elements. This is expected to be very useful as it paves the way for further thorough mathematical analyses of shell elements. A particularly important motivation for this is the understanding and treatment of the deficiencies associated with the analysis of thin shells (among which is the locking phenomenon). We then survey these deficiencies, in the framework of the asymptotic behaviour of shell models. We conclude the article by giving some detailed guidelines to numerically assess the performance of shell finite elements when faced with these pathological phenomena, which is essential for the design of improved procedures.

Interval Finite Element Analysis of Structural Dynamic Problems

2015 ◽  
Vol 8 (2) ◽  
pp. 382-389 ◽  
Author(s):  
Naijia Xiao ◽  
Rafi L. Muhanna ◽  
Francesco Fedele ◽  
Robert L. Mullen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Problems ◽  
Element Analysis ◽  
Structural Dynamic

Finite Element Analysis of Automobile Drive Axle Housing Based on ANSYS

2015 ◽  
Vol 741 ◽  
pp. 223-226
Author(s):  
Hai Bin Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Performance ◽  
Element Analysis ◽  
Shell Elements ◽  
Fea Model ◽  
Automobile Design ◽  
Housing Structure ◽  
Drive Axle ◽  
Drive Axle Housing

The performance of automobile drive axle housing structure affects whether the automobile design is successful or not. In this paper, the author built the FEA model of a automobile drive axle housing with shell elements by ANSYS. In order to building the optimization model of the automobile drive axle housing, the author studied the static and dynamic performance of it’s structure based on the model.

scholarly journals Finite Element Analysis of the Parthenon marble block- steel clamp system response under acceleration

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 155
Author(s):  
Zacharias Vangelatos ◽  
Michail Delagrammatikas ◽  
Olga Papadopoulou ◽  
Charalampos Titakis ◽  
Panayota Vassiliou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Engineering ◽  
Conservation Status ◽  
Intrinsic Stress ◽  
System Response ◽  
Confined Space ◽  
Structural System ◽  
Element Analysis ◽  
Scientific Fields

<p class="Abstract">Finite element analysis is employed to investigate the mechanical behaviour and failure scenarios of the marble block–steel clamp ancient masonry system utilised in the Parthenon (Athens Acropolis) under static loading analysis. The input data for the model are acquired by the laboratory testing of early 20th century restoration steel clamps, such as through tensile strength measurements and metallography, as well as bibliographic sources from various scientific fields (i.e. material properties, archaeometry, restoration, structural engineering and geology). Two different embedding materials (Portland cement mortar and lead), used for the nesting of the clamps, are examined under bending or stretching, induced by acceleration forces. The conservation status of the materials is taken into account by employing an intrinsic stress, as is the case when corrosion products build up in a confined space. The aim of this work is to provide a tool for the assessment of the conservation potential of the marble blocks in parts of the monument that require specific attention. Simulation results indicate the resilience of the Parthenon’s structural system under most examined scenarios and highlight the importance of intrinsic stresses, the existence of which may lead to the fracture of the marble blocks under otherwise harmless loading conditions.</p>

scholarly journals Finite Element Analysis of Foundation Pile Anchor Support System

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhenli Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Construction Projects ◽  
Analysis Method ◽  
Support Structure ◽  
Foundation Pit ◽  
Element Analysis ◽  
High Rise ◽  
Finite Element Analysis Method ◽  
Foundation Pile

With the continuous development of urban construction projects in HebeiProvince, the rise and development of high-rise buildings and undergroundengineering, the design and research of foundation pit support structure has become more and more important. The design of the foundation pit support structure directly affects the settlement and position changes of the building itself and the surrounding stratum. In this paper, the characteristics of foundation pit support are analyzed, and the related theories of finite element analysis method are introduced. Combined with the actual situation of Hebei Province, the finite element analysis method is used to simulate the construction method of foundation pile anchor support structure system. The design was analyzed and studied.

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