Elastic Modulus Adjustment Improved Convergement Schemes Using Variable Local Constraints

2005 ◽  
Author(s):  
R. Adibi-Asl ◽  
Ihab F. Z. Fanous ◽  
R. Seshadri
Keyword(s):  
Finite Element Analysis ◽  
Elastic Modulus ◽  
Simple Procedure ◽  
Upper Bounds ◽  
Lower And Upper Bounds ◽  
Element Analysis ◽  
Local Constraints ◽  
Limit Loads ◽  
Linear Elastic ◽  
Degree Of Convergence

Elastic modulus adjustment procedures (EMAP) have been employed to determine limit loads of pressure components. On the basis of linear elastic Finite Element Analysis (FEA) with non-hardening elastic properties, i.e., by specifying spatial variations in the elastic modulus, numerous set of statically admissible and kinematically admissible distributions can be generated, and both lower and upper bounds on limit loads can be obtained. Some methods such as the classical, r-node and mα methods provide limit loads on the basis of partly-converged distributions, whereas the accuracy of linear matching procedures rely on fully converged distributions. In this paper, a criterion for establishing the degree of convergence of EMAP is developed, and a simple procedure for achieving improved convergence is described. The procedure is applied to some practical pressure component configurations.

Limit Load Analysis of Cracked Components Using the Reference Volume Method

2006 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Limit Load ◽  
Multiple Cracks ◽  
Element Analysis ◽  
Limit Loads ◽  
Integrity Assessment ◽  
Reference Volume ◽  
Volume Method

Cracks and flaws occur in mechanical components and structures, and can lead to catastrophic failures. Therefore, integrity assessment of components with defects is carried out. This paper describes the Elastic Modulus Adjustment Procedures (EMAP) employed herein to determine the limit load of components with cracks or crack-like flaw. On the basis of linear elastic Finite Element Analysis (FEA), by specifying spatial variations in the elastic modulus, numerous set of statically admissible and kinematically admissible distributions can be generated, to obtain lower and upper bounds limit loads. Due to the expected local plastic collapse, the reference volume concept is applied to identify the kinematically active and dead zones in the component. The Reference Volume Method is shown to yield a more accurate prediction of local limit loads. The limit load values are then compared with results obtained from inelastic finite element analysis. The procedures are applied to some practical components with cracks in order to verify their effectiveness in analyzing crack geometries. The analysis is then directed to geometries containing multiple cracks and three-dimensional defect in pressurized components.

scholarly journals Finite Element Analysis on the Unloading Elastic Modulus of Aluminum Foams by Unit-cell Model

2018 ◽  
Vol 288 ◽  
pp. 012069 ◽  
Author(s):  
F Triawan ◽  
B A Budiman ◽  
F B Juangsa ◽  
L A Prananto ◽  
M Aziz
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Cell Model ◽  
Unit Cell ◽  
Unit Cell Model ◽  
Aluminum Foams ◽  
Element Analysis

The equivalent method of double V-wing honeycombs on the in-plane dynamic impact

2021 ◽  
pp. 073168442199086
Author(s):  
Yunfei Qu ◽  
Dian Wang ◽  
Hongye Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Energy Absorption ◽  
Width Ratio ◽  
Size Factor ◽  
Dynamic Impact ◽  
Element Analysis ◽  
Equivalent Method

The double V-wing honeycomb can be applied in many fields because of its lower mass and higher performance. In this study, the volume, in-plane elastic modulus and unit cell area of the double V-wing honeycomb were analytically derived, which became parts of the theoretical basis of the novel equivalent method. Based on mass, plateau load, in-plane elastic modulus, compression strain and energy absorption of the double V-wing honeycomb, a novel equivalent method mapping relationship between the thickness–width ratio and the basic parameters was established. The various size factor of the equivalent honeycomb model was denoted as n and constructed by the explicit finite element analysis method. The mechanical properties and energy absorption performance for equivalent honeycombs were investigated and compared with hexagonal honeycombs under dynamic impact. Numerical results showed a well coincidence for each honeycomb under dynamic impact before 0.009 s. Honeycombs with the same thickness–width ratio had similar mechanical properties and energy absorption characteristics. The equivalent method was verified by theoretical analysis, finite element analysis and experimental testing. Equivalent honeycombs exceeded the initial honeycomb in performance efficiency. Improvement of performance and weight loss reached 173.9% and 13.3% to the initial honeycomb. The double V-wing honeycomb possessed stronger impact resistance and better load-bearing capacity than the hexagonal honeycomb under impact in this study. The equivalent method could be applied to select the optimum honeycomb based on requirements and improve the efficiency of the double V-wing honeycomb.

Limit Load Analysis of Cracked Components Using the Reference Volume Method

2006 ◽  
Vol 129 (3) ◽  
pp. 391-399 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Elastic Modulus ◽  
Three Dimensional ◽  
Local Limit ◽  
Limit Load ◽  
Multiple Cracks ◽  
Element Analysis ◽  
Limit Loads ◽  
Integrity Assessment ◽  
Reference Volume ◽  
Volume Method

Cracks and flaws occur in mechanical components and structures, and can lead to catastrophic failures. Therefore, integrity assessment of components with defects is carried out. This paper describes the Elastic Modulus Adjustment Procedures (EMAP) employed herein to determine the limit load of components with cracks or crack-like flaw. On the basis of linear elastic Finite Element Analysis (FEA), by specifying spatial variations in the elastic modulus, numerous sets of statically admissible and kinematically admissible distributions can be generated, to obtain lower and upper bounds limit loads. Due to the expected local plastic collapse, the reference volume concept is applied to identify the kinematically active and dead zones in the component. The Reference Volume Method is shown to yield a more accurate prediction of local limit loads. The limit load values are then compared with results obtained from inelastic FEA. The procedures are applied to a practical component with crack in order to verify their effectiveness in analyzing crack geometries. The analysis is then directed to geometries containing multiple cracks and three-dimensional defect in pressurized components.

scholarly journals Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

10.2341/08-73 ◽  
2009 ◽  
Vol 34 (2) ◽  
pp. 223-229 ◽  
Author(s):  
A. O. Spazzin ◽  
D. Galafassi ◽  
A. D. de Meira-Júnior ◽  
R. Braz ◽  
C. A. Garbin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Elastic Modulus ◽  
Resin Composite ◽  
Resin Cement ◽  
Zirconia Ceramic ◽  
Element Analysis ◽  
Fiber Posts ◽  
Stress Levels ◽  
Glass Fiber Posts

Clinical Relevance According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.

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.

scholarly journals Mechanical behavior of ballasted railway track stabilized with polyurethane: A finite element analysis

2018 ◽  
Vol 251 ◽  
pp. 04056 ◽  
Author(s):  
Zelimkhan Khakiev ◽  
Alexander Kruglikov ◽  
Georgy Lazorenko ◽  
Anton Kasprzhitskii ◽  
Yakov Ermolov ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Finite Element Simulation ◽  
Elasticity Modulus ◽  
Railway Track ◽  
Binding Agent ◽  
Element Analysis ◽  
Linear Elastic ◽  
Element Simulation

Analysis of mechanical behavior of ballast shoulder of railway track reinforced by polyurethane binding agent has been performed by the method of finite-element simulation Limitation of the model of linear-elastic properties of geocomposite has been displayed. Dependence of elasticity modulus of geocomposite on deformation value has been suggested. Influence of penetration depth of polyurethane binding agent on behavior of railway track construction under different train loads has been studied.

Considerations on Using the Strut and Tie Method for Modelling Coupling Beams

2017 ◽  
Vol 21 ◽  
pp. 116-121
Author(s):  
Vasile Murăraşu ◽  
Vasile Mircea Venghiac
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Linear Analysis ◽  
Numerical Analyses ◽  
Coupling Beam ◽  
Coupling Beams ◽  
Structural Walls ◽  
Element Analysis ◽  
Linear Elastic ◽  
Strut And Tie

This paper presents a synthesis of the numerical analyses regarding the method of modelling the coupling beams of structural walls. The directions of the struts and ties are established according to the results obtained after a linear-elastic finite element analysis. The results obtained after modelling using the Strut and Tie Method, with the struts and ties oriented along the diagonals of the coupling beam, coincide with the results obtained by applying the theory provided by EC8, which proves the viability of the method. This is also confirmed by the results obtained after a non-linear analysis was carried out in the LUSAS finite element environment.

Exploration of Fine Lines Profile Effects in Flexographic Printing

2013 ◽  
Vol 315 ◽  
pp. 458-462 ◽  
Author(s):  
Mohd Sallehuddin Yusof ◽  
Z. Said ◽  
M.I. Maksud
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Laser Machining ◽  
Element Analysis ◽  
Printing Plate ◽  
Computational Framework ◽  
Linear Elastic ◽  
Exploration Tool ◽  
Flexographic Printing ◽  
Hyperelastic Models

Line profile is an important consideration in printing functional devices particularly in printing very fine line for electronic applications. Since laser machining provides the opportunity to apply extreme fine lines with different profiles where unachievable mechanically. Laser ablated printing plate are costly to produce, hence it is appropriate to investigate this within a computational framework beforehand. Therefore several designs will be investigated with different geometry as the variables using both linear elastic and non linear hyperelastic models. The results exhibits that finite element analysis serves appropriately as an exploration tool where it worked well with experimental results.

Application of Two Methods for Notch Fatigue Life Prediction

2011 ◽  
Vol 488-489 ◽  
pp. 654-657
Author(s):  
Radu Negru ◽  
Liviu Marsavina ◽  
Hannelore Filipescu ◽  
Cristiana Caplescu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Reduction Factor ◽  
Volumetric Method ◽  
Life Assessment ◽  
Strength Reduction Factor ◽  
Element Analysis ◽  
Linear Elastic ◽  
Notched Specimens

The aim of this paper is the application of two methods for notch fatigue life assessment, methods which are based on finite element analysis: the theory of critical distances and the volumetric method. Firstly, un-notched and notched specimens (for three different geometries) were tested in tension under constant-amplitude loading. The use of theory of critical distances (TCD) to predict the notch fatigue life involves the determination of the material characteristic length L based on experimental results obtained for the un-notched and one type of notched specimens. For the others notched geometries, based on linear-elastic finite element analysis, the fatigue strength is predicted using the TCD. In order to apply the volumetric method, elastic-plastic stress field around notches are considered and notch strength reduction factor are determined. Finally, the predictions of the two methods were compared with experimental fatigue data for notched specimens.

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