Inelastic Dynamic Analysis of Steel Structure Using Force Analogy Method

2012 ◽  
Vol 166-169 ◽  
pp. 304-309 ◽  
Author(s):  
Shi Qiang Song ◽  
Gang Li
Keyword(s):  
Dynamic Analysis ◽  
Plastic Hinge ◽  
Nonlinear Dynamic Analysis ◽  
Steel Structure ◽  
Response Analysis ◽  
Analysis Method ◽  
Element Analysis ◽  
Analogy Method ◽  
Traditional Algorithm ◽  
Response State

Force analogy method is a kind of nonlinear dynamic analysis method. Analyzing inelastic structural behavior by using plastic hinge theory, it is widely appropriate to many structures with different material properties and very time efficient and numerically accurate without complicated iterative computations in traditional algorithm. Compared with the traditional finite-element analysis method, dynamic response analysis based on force analogy method has obvious advantages. The application of force analogy method to a steel structure is presented and the analysis result shows that the method algorithm can represent each response state of the structure in real-time and has the very good accuracy and practical.

Three-Stage Multiscale Nonlinear Dynamic Analysis Platform for Building-Level Loss Estimation

2015 ◽  
Vol 31 (2) ◽  
pp. 1021-1042 ◽  
Author(s):  
In Ho Cho ◽  
Keith Porter
Keyword(s):  
Dynamic Analysis ◽  
Information Transfer ◽  
Large Scale ◽  
Nonlinear Dynamic Analysis ◽  
Loss Estimation ◽  
Element Analysis ◽  
Global Dynamic ◽  
Micro Level ◽  
Analysis Platform ◽  
Vulnerability Functions

Large-scale loss estimation needs vulnerability functions that relate ground motion to repair cost for each of many building classes. A challenge to generating analytical vulnerability functions for a building class is that one needs to reflect seismic performance at several scales, from the size of cracks to the whole building. Here, we propose a three-stage multiscale platform tackling a general reinforced concrete (RC) building containing complex walls: (1) at the micro level, a microphysical mechanism-based parallel finite element analysis (FEA) engine captures microscopic nonlinearities; (2) the macro level handles computationally expensive dynamic analyses of buildings; (3) the meso level manages interscale information transfer and describes floor-specific variability. Multiple parallel FEA engines run in concert with a stand-alone dynamic analysis platform. Importantly, the micro level resolves damage phenomena explicitly—no fragility inference is required—propagating component damage to global dynamic analysis. Now, one can link microscopic damage to building seismic loss.

Analysis and Control of Maglev Flywheel Rotor in the Wind Generator

2012 ◽  
Vol 608-609 ◽  
pp. 513-516
Author(s):  
Hua Chun Wu ◽  
Xu Jun Lv ◽  
Gao Gong
Keyword(s):  
Reduction Method ◽  
Response Analysis ◽  
Analysis Method ◽  
Element Analysis ◽  
Lqr Control ◽  
Finite Element Analysis Method ◽  
Wind Generator ◽  
Simulation Results ◽  
And Control ◽  
Flywheel Rotor

The application of maglev flywheel in wind generator is investigated. The dynamics analysis of maglev flywheel rotor has been performed including the critical speed analysis and unbalance response analysis, which took into account the gyroscopic effect by using of finite element analysis method. Based on the model reduction method, the modeling and LQR control of maglev flywheel rotor is presented, the simulation results show stable levitation and good levitated rotation.

Nonlinear Dynamic Analysis of an Icosahedron Frame which Exhibits Chaotic Behavior

2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Lucas W. Just ◽  
Anthony M. DeLuca ◽  
Anthony N. Palazotto
Keyword(s):  
Dynamic Response ◽  
Boundary Conditions ◽  
Dynamic Analysis ◽  
Chaotic Behavior ◽  
Research Question ◽  
Nonlinear Dynamic Analysis ◽  
Surface Force ◽  
Element Analysis ◽  
Point Distribution ◽  
Chaotic Response

The research question addressed is whether a lighter than air vehicle (LTAV), which uses an internal vacuum to become positively buoyant, can be designed to provide extended loiter for U.S. Air Force applications. To achieve a vacuum, internal gases are evacuated from the vessel, which creates a dynamic response in the supporting structural frame. This paper considers the frame of an icosahedron shaped LTAV subject to external atmospheric pressure evacuated at varying rates. A static finite element analysis documented in previous research revealed a snapback phenomenon in the frame members under certain loading conditions. A nonlinear chaotic response was observed when a dynamic analysis was conducted with the same boundary conditions used in the static analysis. The chaotic response for a variety of boundary conditions, generated by varying the rate of evacuation, similar to a ramp input, is determined. An analysis of the dynamic response is determined nonlinearly using a method that relies on a reference point distribution of external pressures to distribute the surface force across the frame. A novel method of combining the power spectral density with a Lyapunov exponent was used to determine the degree of nonlinearity and chaotic response for each boundary condition examined.

DYNAMIC ANALYSIS OF FRAMES WITH MATERIAL AND GEOMETRIC NONLINEARITIES BASED ON THE SEMIRIGID TECHNIQUE

2008 ◽  
Vol 08 (03) ◽  
pp. 415-438 ◽  
Author(s):  
F. T. K. AU ◽  
Z. H. YAN
Keyword(s):  
Dynamic Analysis ◽  
Stiffness Matrix ◽  
Plastic Hinge ◽  
Nonlinear Dynamic Analysis ◽  
Yield Condition ◽  
Computationally Efficient ◽  
Time Step ◽  
Geometric Nonlinearities ◽  
Frame Element ◽  
Sum Of Products

This paper presents a method for nonlinear dynamic analysis of frames with material and geometric nonlinearities which is based on the semirigid technique. The plastic hinge that accounts for the material nonlinearity is modeled as a pseudo-semirigid connection with nonlinear hysteretic moment-curvature characteristics at the element ends. The stiffness matrix of a frame element with material and geometric nonlinearities is expressed as the sum of products of the standard stiffness matrix and the geometric stiffness matrix of the element, with their corresponding correction matrices based on the plasticity factors developed from the section flexural stiffness at the plastic hinge locations. The combined stress yield condition is used for the force state determination of plastic hinges, and force equilibrium iterations and geometry updating for frames are carried out in every time step. When the key parameters of a structure are updated in a time step, the time step is split up into substeps to ensure accuracy while keeping the computations to a reasonable amount. The plastic rotation history can be calculated directly or in an approximate indirect way. The method is computationally efficient and it needs no additional connection elements, which makes it convenient for incorporation into existing linear dynamic analysis programs. Besides, the method can handle accurately and efficiently the dynamic analysis of nonlinear frames using relatively large time steps in conjunction with time step subdivision to cope with key parameter changes. A portal frame is used to verify the correctness of the proposed method. A more complicated five-story frame is used to illustrate the applicability and performance of the proposed method.

Study on Actual Finite Element Analysis of Steel Structure

2014 ◽  
Vol 501-504 ◽  
pp. 538-542
Author(s):  
Qun Wei ◽  
Hua Jiang ◽  
Cheng Shan Peng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steel Structure ◽  
Computer Hardware ◽  
Analysis Method ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Plate Size ◽  
Acceptable Method ◽  
Steel Joints

Due to the limitation conditions of computer hardware in the past, the structure members need to be simplified in order to save the computing resources during the finite element analysis (FEA). During FEA of Steel joints, the simplified model is considered as hinge joint, rigid joint or half-rigid joint, which is different with the actual force. With the improvement of computer technology and hardware, actual finite element analysis method (AFEA) is proposed in consider of influence of actual model, welding, plate size and bolts, which is a more acceptable method in Precision compared with last.

Analysis on Aseismic Performance of the Beijing Yintai Center

2010 ◽  
Vol 163-167 ◽  
pp. 3872-3877
Author(s):  
Zhi Qiang Zhang ◽  
Ai Qun Li ◽  
Yong Sun ◽  
Meng Ya Huang
Keyword(s):  
Seismic Behavior ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Response Analysis ◽  
Analysis Method ◽  
Element Analysis ◽  
Plastic Analysis ◽  
Earthquake Action ◽  
Rare Earthquake ◽  
Three Dimensional Finite Element

In this study, the seismic behavior of the main tower building of Beijing Yintai Center is presented with regard to the dynamic characteristics analysis and seismic response analysis. Firstly, by means of three-dimensional finite element analysis software, the dynamic properties and seismic responses under frequent earthquake action of the structure are obtained, respectively. It can be seen that the structure has a rational arrangement for structural elements and has a good seismic behavior. Then, the seismic behavior of the structure is studied through the dynamic elasto-plastic analysis method and static elasto-plastic analysis method under rare earthquake. Analysis results of both analysis methods show that the behavior of the structure accords with the earthquake performance objectives and the structure would not collapse under the rare earthquake action.

Shock Analysis and Design Method of Vibration Isolating System in the Time Domain

2005 ◽  
Author(s):  
Yinglong Zhao ◽  
Lin He ◽  
Zhiqiang Lv ◽  
Yu Wang
Keyword(s):  
Dynamic Analysis ◽  
Time Domain ◽  
Design Analysis ◽  
Analysis Method ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Protection Measures ◽  
Analysis And Design ◽  
Shock Protection ◽  
The Time Domain

Choosing the equipment with good shock-resistant performance and taking shock protection measures while designing the onboard settings, the safety of onboard settings can be assured when warships, especially submarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i.e., the maximum displacement of the equipment relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock-resistant performance of the shock-resistant equipments should be verified in the design phase of the equipments. The shock design analysis methods used before and now includes shock design number method (static g-method), dynamic analysis in the time domain and dynamic design analysis method (DDAM). The FEA (Finite Element Analysis) software, for example, MSC.NASTRAN®, can be used for shock design analysis of the shock-resistant equipments. MSC.NASTRAN are used for shock design analysis of floating raft vibration isolating equipment with dynamic analysis method in the time domain in this paper, and the analysis results are in agreement with the test results. The shock design analysis method used in this paper can be used to analyze the shock-resistant performance of onboard shock-resistant equipments.

Seismic Qualification of Piping Systems by Detailed Inelastic Response Analysis: Part 4 — Second Round Benchmark Analyses With Stainless Steel Piping Component Test

2017 ◽  
Author(s):  
Tomoyoshi Watakabe ◽  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Morishita ◽  
Tadahiro Shibutani ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Seismic Design ◽  
Analysis Procedure ◽  
Response Analysis ◽  
Analysis Method ◽  
Element Analysis ◽  
Inelastic Response ◽  
Current Design ◽  
Steel Piping

Some studies concerning ultimate strength of piping under seismic loads concluded that there is a large design margin until failure, even if the stress calculated based on the current design method does not satisfy design criteria. To provide a more rational seismic design, a new Code Case for seismic design of piping is now under development in the framework of JSME Nuclear Codes and Standards. The Code Case incorporates a dynamic elastic-plastic analysis procedure by employing finite element analysis as an alternative to the current design analysis method of elastic assumption. To confirm the applicability of inelastic response analysis, benchmark analyses have been conducted. In the first round benchmark, a carbon steel elbow analysis was performed. In this report, a second round benchmark with a stainless steel elbow and tee is introduced. The second benchmark aims to establish an analysis procedure for stainless steel piping and tee piping of complicated shapes. The second benchmark results provided a practical analysis method for stainless steel piping, and the Code Case was expanded so that it could be applied not only to carbon steel piping but also to stainless steel piping. The second benchmark also challenged analyses of a tee having complicated geometry. These results provide some important knowledge, and they will be included in the Code Case.

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