The Elastic Modulus Adjustment Procedure (EMAP) for Shakedown

2008 ◽  
Author(s):  
R. Adibi-Asl ◽  
W. Reinhardt
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Time History ◽  
Structure Model ◽  
Stress Distributions ◽  
Element Analysis ◽  
Shakedown Analysis ◽  
Adjustment Procedure ◽  
Linear Finite Element ◽  
History Analysis

A simple and systematic procedure is proposed for shakedown analysis using combination of linear and non-linear finite element analysis (FEA). The method can identify the boundary between the shakedown and ratcheting domains directly does not require a time history analysis (non-cyclic). The proposed method is based on elastic modulus adjustment procedure (EMAP) and non-cyclic elastic-plastic FEA. The aim of EMAP is to generate statically admissible stress distributions and kinematically admissible strain distributions. By modifying the local elastic moduli it is possible to obtain an inelastic-like stress redistribution. The method is first demonstrated with a two-bar structure model based on analytical routine. The analysis is then applied to some typical shakedown problems including the “classical Bree problem” and the “bi-material cylinder”.

Ratchet Boundary Determination Using a Noncyclic Method

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
R. Adibi-Asl ◽  
W. Reinhardt
Keyword(s):  
Elastic Moduli ◽  
Load Carrying Capacity ◽  
Structure Model ◽  
Stress Distributions ◽  
Radial Temperature Gradient ◽  
Element Analysis ◽  
Radial Temperature ◽  
Adjustment Procedure ◽  
Boundary Determination ◽  
Load Carrying

A simple and systematic procedure is proposed for shakedown analysis using a combination of linear and nonlinear finite element analysis (FEA). The method can identify the boundary between the shakedown and ratcheting domains directly and does not require a cyclic analysis (noncyclic). The proposed method performs an elastic-plastic FEA to determine the reduction in load carrying capacity due to the cyclic secondary loads. An elastic modulus adjustment procedure is then used to generate statically admissible stress distributions and kinematically admissible strain distributions under the applied primary loads. By modifying the local elastic moduli it is possible to obtain inelastic-like stress redistribution. The method is demonstrated with a “two-bar structure” model based on analytical routine. The analysis is then applied to some typical shakedown problems including the “classical Bree problem,” the “bimaterial cylinder,” and the “plate with a hole subjected to radial temperature gradient.”

Finite Element Analysis of a Sliding Isolation Steel Structure

2011 ◽  
Vol 368-373 ◽  
pp. 1156-1159
Author(s):  
Xin Zhong Zhang ◽  
Lian Juan Miao
Keyword(s):  
Seismic Isolation ◽  
Time History ◽  
Steel Structure ◽  
Seismic Structure ◽  
Structure Model ◽  
Analysis Software ◽  
Element Analysis ◽  
Sliding Isolation ◽  
History Analysis ◽  
Excitation Time

Using general analysis software ANSYS establish non-isolated and isolation steel villa structure model, selecting a reasonable seismic wave and obtaining this via seismic excitation time-history analysis: sliding isolated structures can reduce seismic upload, slip shift seismic isolation layer absorbs most of the energy, can reduce seismic response of 23.1%~78.8% compared with ordinary anti-seismic structure. the level of isolation effect is remarkable.

Application of Earthquake Resistance Analysis Technique in the Design of Constructional Engineering

2013 ◽  
Vol 756-759 ◽  
pp. 4482-4486
Author(s):  
Chun Gan ◽  
Xue Song Luo
Keyword(s):  
Response Spectrum ◽  
Structural Response ◽  
Time History ◽  
Economic Losses ◽  
Element Analysis ◽  
Architectural Engineering ◽  
Analysis Technique ◽  
History Analysis ◽  
Earthquake Resistant ◽  
History Of

In recent years, frequent earthquakes have caused great casualties and economic losses in China. And in the earthquake, damage of buildings and the collapse is the main reason causing casualties. Therefore, in the design of constructional engineering, a seismicity of architectural structure is the pressing task at issue. Through time history analysis method, this paper analyzes the time history of building structural response and then it predicts the peak response of mode by response spectrum analysis. Based on this, this paper constructs a numerical simulation model for the architecture by using finite element analysis software SATWE. At the same time, this paper also calculates the structure seismic so as to determine the design of each function structure in architectural engineering design and then provides reference for the realization of earthquake-resistant building.

Analysis of Dynamic Response of a Railway Locomotive Using ANSYS

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Srihari Palli ◽  
Raghuveer Dontikurti ◽  
Rakesh Chandmal Sharma ◽  
Neeraj Sharma
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Time History Analysis ◽  
Surface Irregularity ◽  
Transient Dynamic Analysis ◽  
Element Analysis ◽  
Car Body ◽  
History Analysis ◽  
Track Surface ◽  
General Time

Transient dynamic analysis (sometimes called time-history analysis) is a technique used to determine the dynamic response of a structure under the action of any general time-dependent loads. The time scale of the loading is such that the inertia or damping effects are considered to be important. Present work is focused on performing the time history analysis of a typical locomotive coach using finite element analysis in Indian railroad conditions. Track surface irregularity in the form of an ellipsoidal bump is modelled with assumptions that the vehicle passes over the bump in 0.144 seconds, variation in displacement at different key locations of the truck and car body models is plotted against time under standard loading conditions. The response pattern of the front and rear portions of the locomotive truck and car body indicate that these locations are more susceptible to wheel excitations compared to that of the centre portions of it as they are away from the centre of gravity of the vehicle due to unbalanced mass distribution.

Optimal Shape Design Under Elastic-Plastic Behavior Based on Reference Volume Method

2011 ◽  
Author(s):  
R. Adibi-Asl
Keyword(s):  
Elastic Modulus ◽  
Optimum Shape ◽  
Shape Design ◽  
Plastic Behavior ◽  
Element Analysis ◽  
Adjustment Procedure ◽  
Linear Elastic ◽  
Reference Volume ◽  
Overlap Joint ◽  
Volume Method

The main objective of this paper is to determine the regions in a component or structure that directly participate in inelastic action (reference volume) using a new robust simplified method, namely the Elastic Modulus Adjustment Procedure (EMAP). The proposed method is based on iterative linear elastic finite element analysis that is implemented by modifying the local elastic modulus of the material at each subsequent iteration. The application of reference volume on optimum shape design is demonstrated through some practical examples including thick-walled cylinder, shank-head component and overlap joint weld. The results show that the reference volume concept can be used to optimize the shape of a body with respect to load carrying capacity and fatigue strength.

Irregular Structure of the Metal Energy Dissipation Wrest Resistant Performance Analysis

2011 ◽  
Vol 105-107 ◽  
pp. 818-822
Author(s):  
Xiao Fei Teng ◽  
Si Yang Chen ◽  
Bin Luo
Keyword(s):  
Time History ◽  
Frame Structure ◽  
Software Modeling ◽  
Element Analysis ◽  
Irregular Structure ◽  
History Analysis ◽  
Framework Model ◽  
Before And After ◽  
Integral Structure ◽  
Dynamic Time

To make a top local adding stories of “L” flat facade irregular frame structure with good resistance to twist and integrity, can better satisfy the requirements of local seismic fortification intensity,using metal damper to this after-adding-stories framework model for processing. Using SAP2000 finite element analysis software modeling and in its install metal damper dynamic time-history analysis before and after. Results show that the structure using metal consumption technology in consume earthquake input energy at the same time can enhance structure rigid and floor wrest resistant and strengthen the lateral stiffness integral structure seismic performance.

Bounded Elastic Moduli Multiplier Technique for Limit Loads: Part 1 - Theory

2022 ◽  
Author(s):  
Sathya Prasad Mangalaramanan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Lower Bound ◽  
Power Law ◽  
Elastic Moduli ◽  
Stress Distributions ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Limit Loads ◽  
Reduced Modulus

Abstract Statically admissible stress distributions are necessary to evaluate lower bound limit loads. Over the last three decades, several methods have been postulated to obtain these distributions using iterative elastic finite element analyses. Some of the pioneering techniques are the reduced modulus, r-node, elastic compensation, and linear matching methods, to mention a few. A new method, called the Bounded Elastic Moduli Multiplier Technique (BEMMT), is proposed and the theoretical underpinnings thereof are explained in this paper. BEMMT demonstrates greater robustness, more generality, and better stress distributions, consistently leading to lower-bound limit loads that are closer to elastoplastic finite element analysis estimates. BEMMT also questions the validity of the prevailing power law based stationary stress distributions. An accompanying research offers several case studies to validate this claim.

Deformation and Stress Analysis of Supported Buttock Contact

1994 ◽  
Vol 208 (1) ◽  
pp. 9-17 ◽  
Author(s):  
P A Dabnichki ◽  
A D Crocombe ◽  
S C Hughes
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Contact Problem ◽  
Stress Analysis ◽  
Stress Distributions ◽  
Body Segment ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Support Surfaces

Non-linear finite element analysis has been used to investigate the contact problem between a buttock and a cushion of varying properties. The buttock tissue has been modelled on the macroscale by assuming it to be a hyperelastic (rubber-like) material with properties that correspond to the overall buttock response. Both rigid and flexible cushions have been considered. The contact between the cushion and the buttock has been modelled assuming both friction and friction-free conditions. The effect of these parameters on the buttock-cushion deformation and the tissue compressive and shear stress distributions have been presented. This study forms part of work towards the development of body segment simulators for use in investigations of seating and other support surfaces.

Study on Seismic Absorption Performance of Assembled Shear Wall Structure under Pre-Stressed Constraint

2020 ◽  
Vol 980 ◽  
pp. 231-238
Author(s):  
Xin Sheng Yin ◽  
Xiao Wei Liu
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Shear Wall ◽  
Wall Structure ◽  
Structure Model ◽  
Earthquake Effect ◽  
Wall Structures ◽  
History Analysis ◽  
New Type ◽  
The New Period

In order to respond to the construction policy of "economy, application, green and beauty" put forward by China in the new period, the assembly structure has gradually become the focus of attention in recent years. Compared with the traditional cast-in-place structure, the assembled structure is more in line with the requirements of energy-saving, material-saving, environmental protection, etc. Therefore, it is of great importance to further study the seismic performance of assembled structures. However, existing assembled shear wall structures often suffer from problems such as the joint position is difficult to construct because of its wet work, and strong component weak nodes often appear. The seismic performance of the joints needs to be further studied and so on. Aiming to solve above problems, a new type of pre-stressed constraint assembled shear wall structure was proposed by us. The structure is connected by pre-stressed tendon to shear wall, and there is no wet operation at the construction site, which is conductive to improving construction quality. When the earthquake occurs, the structure can increase its self-shock period by changing its own stiffness, so as to reduce the earthquake stress. Meanwhile, many conditions to improve the ductility of the structure do not need to be considered, thus avoid the waste of steel materials. Based on the time history analysis of cast-in-place shear wall structure model and pre-stressed shear wall structure model, the results of calculation show that: compared with cast-in-place shear wall structure, the pre-stressed shear wall structure can effectively reduce the earthquake effect by about 90%.

Numerical Techniques for Predicting Pyroshock Responses of Aerospace Structures

2010 ◽  
Vol 108-111 ◽  
pp. 1043-1048 ◽  
Author(s):  
Yong Jian Mao ◽  
Han Jun Huang ◽  
Yi Xia Yan
Keyword(s):  
Energy Analysis ◽  
Response Spectrum ◽  
Time History ◽  
Statistical Energy Analysis ◽  
Numerical Techniques ◽  
Element Analysis ◽  
Aerospace Structures ◽  
History Analysis ◽  
Structural Responses ◽  
Electrical Components

Pyroshock responses of aerospace structures/systems are significantly important for design and valuation of space systems because it is a harsh environment for the systems, especially the electrical components. But the designers strongly rely on tests because, up to now, there have not been effective analytical and even numerical techniques for this problem. Fortunately, a number of researchers have been making efforts to build numerical techniques for structural responses prediction under this kind of special dynamic environments. This paper presents the techniques of time-history analysis, response spectrum analysis, statistical energy analysis and a synthetic technique composed of hydrocode analysis, time-domain finite element analysis (FEA) and statistical energy analysis. Further work and development trends are discussed in the end.

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