Seismic Design Study on Cantilever Cylindrical Shells

1977 ◽  
Vol 99 (4) ◽  
pp. 600-604 ◽  
Author(s):  
J. N. C. Wu ◽  
J. F. Cory
Keyword(s):  
Finite Element ◽  
Shell Structure ◽  
Seismic Analysis ◽  
Cylindrical Shells ◽  
Building Blocks ◽  
Beam Element ◽  
Dynamic Responses ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Beam Elements

The best way to design a nuclear steam generating system to withstand seismic stresses is to establish a mathematical model, to which seismic loading can be applied, to determine the dynamic responses of the system. A practical approach for establishing such a model is to idealize the components in terms of beam elements which form the essential building blocks of the analytical model. The major shell structures of reactor vessels and steam generators are usually supported at a single elevation in the system, and are often simulated by cantilever beam elements. The use of a beam element to represent shell structure must be justified. This paper presents the results of a parametric study of thin-walled cylindrical shells which are clamped at one end while the other end is free. By using 3-D plate/shell finite element analysis, the region of application, where the beam element can reasonably simulate to shell structure, has been defiined as the combination of its geometrical parameters, e.g., the thickness/radius and length/radius. As an illustrative example, the 3-D finite element method has been used to investigate the seismic analysis of a cantilever cylindrical shell similar to the Clinch River LMFBR reactor vessel. The numerical values are compared with those produced by a beam element model. The results and conclusions obtained by this investigation can be applied to improve dynamic modeling techniques in general.

Finite Element Analysis of Non-Uniform Beam Made of Axially FGM Subjected to Multiple Loads

2015 ◽  
Vol 764-765 ◽  
pp. 1170-1174
Author(s):  
Thanh Huong Trinh ◽  
Buntara Sthenly Gan ◽  
Dinh Kien Nguyen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Axial Direction ◽  
Beam Element ◽  
Functionally Graded ◽  
Dynamic Responses ◽  
Moving Loads ◽  
Element Analysis ◽  
Cross Sectional ◽  
Graded Materials

The dynamic response of non-uniform Timoshenko beams made of axially functionally graded materials subjected to multiple moving point loads is studied by using the finite element method. The material properties are assumed to vary continuously in the axial direction according to a power law. A beam element, taking the effects of shear deformation and cross-sectional variation into account, is formulated by using exact polynomials obtained from the governing differential equations of a homogenous Timoshenko beam element. The dynamic responses of the beams are computed by using the implicit Newmark method. The numerical results show that the dynamic characteristics of the beams are greatly influenced by the number of moving loads. The effects of the distance between the moving loads, material non-homogeneity, section profile as well as aspect ratio on the dynamic response of the beams are investigated in detail and highlighted.

Modeling of the Dynamics of Jointed Beam Structures

2003 ◽  
Author(s):  
Yaxin Song ◽  
D. Michael McFarland ◽  
L. A. Bergman ◽  
C. J. Hartwigsen ◽  
Alexander F. Vakakis
Keyword(s):  
Finite Element ◽  
Dynamic Properties ◽  
Beam Element ◽  
Dynamic Responses ◽  
Hysteretic Behavior ◽  
Joint Interface ◽  
Element Analysis ◽  
Stick Slip ◽  
Beam Structures ◽  
Joint Parameters

Mechanical joints can have significant effects on the dynamics of assembled structures. The goal of our work is to develop physics based, reduced-order, finite element models that are capable of replicating the effects of joints on vibrating structures. Various studies have shown that micro and macro-slip along the joint interface cause the interface stiffness to change and introduce energy dissipation, leading to the observed hysteresis. The authors recently developed the so-called adjusted Iwan beam element (AIBE) for finite element analysis of jointed beam structures. The element consists of two adjusted Iwan models that are arranged to give two-dimensional beam behavior. The adjusted Iwan model is a combination of springs and frictional sliders that exhibits hysteretic behavior due to the stick-slip behavior of the sliders. In this paper, the sensitivity of the performance of an adjusted Iwan model, particularly its capacity to dissipate energy, to variations in its parameters is studied. Parametric analysis is also carried out on the adjusted Iwan beam element to investigate the effects of joint parameters on dynamic responses of jointed beams. Hammer tests are conducted on a jointed beam and its monolithic counterpart. The decay envelopes of impulsive responses for the two systems exhibit distinctly different dynamic properties. To verify that the adjusted Iwan beam element is capable of actually modeling the effects of joints on a vibrating structure, numerical simulations are performed of two hammer tests with different forcing levels. The joint parameters of the jointed beam are identified from the experimentally-obtained acceleration response from one hammer test by using a multi-layer feed-forward neural network (MLFF). Then, using the identified joint parameters, acceleration responses of the jointed beam in the other hammer test are predicted. The capability of the AIBE to capture the effects of bolted joints on the dynamic responses of beam structures is demonstrated through good agreement between simulated and experimental results.

Crash/Crush Analysis of Vehicle Structures Utilizing Thin-Walled Beam Elements

1997 ◽  
Author(s):  
Xiaodong Tang ◽  
James C. Cheng
Keyword(s):  
Finite Element ◽  
Computer Program ◽  
Computing Time ◽  
Beam Element ◽  
Traditional Theory ◽  
Thin Wall ◽  
Element Analysis ◽  
Beam Elements ◽  
Integration Schemes ◽  
Thin Walled

Abstract Using beam element in finite element analysis of automotive structures in the event of crash may significantly reduces the number of elements required to model the structures. It may significantly reduces the computing time for nonlinear integration. More significantly, it takes less time to establish, post-process and modify the models and is therefore, suitable for upfront engineering and concept analysis at early design stages. Considerable studies on beam elements (1–4) have been conducted and many commercial and academic finite element codes (5–7) incorporated it in their libraries. These beam elements are mostly based on the traditional theory that considers the deformation due to yielding and large displacement. However, the buckling phenomenon in the thin-walled components is not reflected in the formulation and therefore, the element are not suitable for thin-walled beams which are quite common in vehicle structures. In this study, a thin-walled beam element is developed to incorporate both the deformation due to material yielding and the deformation due to the buckling of the thin wall plates. The buckling characteristics of the plates is approximately and equivalently converted into the behavior of crush hinge. Like the conventional plastic hinges, the crush hinges are formulated into the finite beam element. The element buckling effect is reflected into the structural response. The beam element is coded into a computer program. The major formulations of beam element, numerical integration schemes of dynamic analysis and contact loading are illustrated in the follow sections. The computer program is used to analyze vehicle structures and the examples are shown in this paper. It should be pointed out that due to the limitations of beam element it is not possible to consider local design features such as small holes and notches. In those cases approximation must be adopted in finite element modeling.

Finite Element Analysis of Composite Cylindrical Shells with and without Cutouts

2012 ◽  
Vol 1 (1) ◽  
pp. 34-38
Author(s):  
B. Siva Konda Reddy ◽  
◽  
CH. Srikanth ◽  
G. Sandeep Kumar ◽  
◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shells ◽  
Element Analysis ◽  
Composite Cylindrical Shells

Incorporation of Spinal Flexibility Measurements Into Finite Element Analysis

1990 ◽  
Vol 112 (4) ◽  
pp. 481-483 ◽  
Author(s):  
Mack G. Gardner-Morse ◽  
Jeffrey P. Laible ◽  
Ian A. F. Stokes
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stiffness Matrix ◽  
Beam Element ◽  
Technical Note ◽  
Element Analysis ◽  
Spinal Motion ◽  
Spinal Flexibility

This technical note demonstrates two methods of incorporating the experimental stiffness of spinal motion segments into a finite element analysis of the spine. The first method is to incorporate the experimental data directly as a stiffness matrix. The second method approximates the experimental data as a beam element.

Dynamic Analysis of Large-Scale Power House

2012 ◽  
Vol 446-449 ◽  
pp. 837-840
Author(s):  
Yu Zhao ◽  
Shu Fang Yuan ◽  
Jian Wei Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Large Scale ◽  
Three Dimensional ◽  
Dynamic Responses ◽  
Dynamic Loads ◽  
Element Analysis ◽  
Power House ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The underwater structure of power house is major structure under the dynamic loads of unit. The vibration problem is very common in operation. So the structures should have sufficient stiffness to resist dynamic loads of unit. This paper establishes three-dimensional finite element models with finite element analysis software—ANSYS. Dynamic characteristics of the power house and dynamic responses of structure under earthquake are analyzed. The results of the computation show that fluid-solid coupling may be ignored when studying dynamic characteristics of structures of the underground power house.

A Non-Prismatic Beam Element for the Optimization of Flexure Mechanisms

2020 ◽  
Author(s):  
Koen Dwarshuis ◽  
Ronald Aarts ◽  
Marcel Ellenbroek ◽  
Dannis Brouwer
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Range Of Motion ◽  
Beam Element ◽  
Precision Engineering ◽  
Element Analysis ◽  
Leaf Springs ◽  
Prismatic Beam ◽  
The Common ◽  
Flexure Joints

Abstract Flexure joints are rapidly gaining ground in precision engineering because of their predictable behavior. However the range of motion of flexure joints is limited due to loss of support stiffness in deformed configurations. Most of the common flexure joints consist of prismatic leaf springs. This paper presents a simple non-prismatic beam formulation that can be used for the efficient modelling of non-prismatic leaf springs. The resulting stiffness and stress computed by the non-prismatic beam element are compared to the results of a finite element analysis. The paper shows that the support stiffness of two typical flexure joints can be increased up to a factor of 1.9 by using non-prismatic instead of prismatic leaf springs.

Numerical Simulation of Galloping for Iced Quad-Bundled Conductor

2014 ◽  
Vol 1025-1026 ◽  
pp. 955-958 ◽  
Author(s):  
Jun Jie Shi ◽  
Ya Nan Li ◽  
Li Qin
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Simulation Analysis ◽  
Time Integration ◽  
Vertical Vibration ◽  
Analysis Model ◽  
Element Analysis ◽  
Beam Elements ◽  
Time Integration Method ◽  
Wake Interference

The theoretical study of galloping can effectively promote anti-galloping techniques. Cable element is utilized to imitate the bundled conductor, and beam elements are used to simulated the spacers, established galloping finite element analysis model which can consider sub-conductors wake interference. The finite element equation was solved by time integration method and the calculation program was compiled by MATLAB. Through numerical simulation analysis, compared the dancing in the case of considering the effect of the sub-conductor wake and ignoring the effect of the sub-conductor wake. The results showed that considering the effect of the wake on aerodynamic loads has a greater vertical vibration amplitude. This method can provide reference for the study of prevention technology on dancing.

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