Limit Load of Anisotropic Components Using the M-Beta Multiplier Method

2004 ◽  
Vol 126 (4) ◽  
pp. 455-460 ◽  
Author(s):  
H. Indermohan ◽  
W. D. Reinhardt ◽  
R. Seshadri
Keyword(s):  
Finite Element ◽  
Yield Criterion ◽  
Limit Load ◽  
Element Model ◽  
Multiplier Method ◽  
Limit Loads ◽  
Inelastic Analysis ◽  
Solid Plate ◽  
Hill's Yield Criterion

The mβ-multiplier method is based on Mura’s extended variational theorems in plasticity, and has been applied previously to isotropic components containing notches and cracks. Lower bound limit loads rapidly converge to inelastic analysis results when the method is used in conjunction with elastic modulus adjustment procedures. In this paper, the mβ-multiplier method is applied to pressure components exhibiting anisotropy. Specifically, the method is applied to the limit load determination of a heat exchanger tubesheet, wherein the tubesheet is modeled as an equivalent solid plate with anisotropic properties. Results are presented for a finite element model where plasticity is represented with Hill’s yield criterion, and a model using a fourth order yield criterion that accounts for compressibility of the tubesheet.

Limit Load of Anisotropic Components Using the M-Beta Multiplier Method

2004 ◽  
Author(s):  
H. Indermohan ◽  
W. D. Reinhardt ◽  
R. Seshadri
Keyword(s):  
Yield Criterion ◽  
Limit Load ◽  
Element Model ◽  
Multiplier Method ◽  
Limit Loads ◽  
Inelastic Analysis ◽  
Solid Plate ◽  
Hill's Yield Criterion ◽  
Matching Techniques

The mβ multiplier method is based on Mura’s extended variational theorems in plasticity, and has been applied previously to isotropic components containing notches and cracks. Lower bound limit loads rapidly converge to inelastic analysis results when the method is used in conjunction with linear matching techniques. In this paper, the mβ-multiplier method is applied to pressure components exhibiting anisotropy. Specifically, the method is applied to the limit load determination of a steam generator tubesheet, wherein the tubesheet is modeled as an equivalent solid plate with anisotropic properties. Results are presented for a finite element model where plasticity is represented with Hill’s yield criterion, and a model using a fourth order yield criterion that accounts for compressibility of the tubesheet.

scholarly journals Elasto - plastic analysis of anisotropic hardening materials by finite element method

1985 ◽  
Vol 7 (1) ◽  
pp. 8-13
Author(s):  
Tran Duong Hien
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Program ◽  
Yield Criterion ◽  
Element Model ◽  
Isotropic Hardening ◽  
Anisotropic Hardening ◽  
Numerical Examples ◽  
Plastic Analysis ◽  
Hill's Yield Criterion

An elasto- plastic analysis for general three dimes10nal problems using a finite element model is presented. The analysis is based on Hill's yield criterion which included anisotropic materials displaying kinematic - isotropic hardening. The validity and practical applicability of the algorithm are illustrated by a number of numerical examples, calculated by a computer program written in fortran.

ROBUST LIMIT LOADS OF SYMMETRIC AND NON-SYMMETRIC PLATE STRUCTURES

1995 ◽  
Vol 19 (3) ◽  
pp. 227-246 ◽  
Author(s):  
S.P. Mangalaramanan ◽  
R. Seshadri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Limit Load ◽  
Robust Methods ◽  
Element Analysis ◽  
Construction Technique ◽  
Plate Structures ◽  
Limit Loads ◽  
Collapse Mechanisms

Robust methods for estimating limit loads of symmetric and non-symmetric plate structures are presented. The methods proposed in this paper for determining limit loads are (1) the r-node method and (2) the semi-circle construction technique. Analytical methods for estimating the limit loads of plate structures are feasible only for simple configurations. Also, determination of limit loads based on assumed collapse mechanisms may not always give upper bound estimates. Limit analysis using inelastic finite element analysis is often elaborate and time consuming. The methods described in this paper circumvent these difficulties. The methods are applied to several configurations of symmetric and non-symmetric plate structures and the limit load estimates are found to be satisfactory.

Simplified Limit Load Estimation of Components With Cracks Using the Reference Two-Bar Structure

2007 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Load Estimation ◽  
Element Analysis ◽  
Limit Loads ◽  
Scaling Relationships ◽  
Simple Scaling

Limit loads for different crack configurations are determined in this paper by invoking the concept of equivalence of “static indeterminacy” that relates a multidimensional component configuration to a “reference two-bar structure.” Simple scaling relationships are developed that enable rapid determination of limit loads. The method is applied to different crack configurations, and the limit loads are compared with corresponding results obtained from inelastic finite element analysis.

Simplified Limit Load Determination Using the mα-Tangent Method

2008 ◽  
Author(s):  
R. Seshadri ◽  
M. M. Hossain
Keyword(s):  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Limit Loads ◽  
Linear Elastic ◽  
Tangent Method ◽  
Mechanical Components

Limit load determination of mechanical components and structures by the mα-tangent method is proposed herein. The proposed technique is a simplified method that enables rapid determination of limit loads for a general class of mechanical components and structures. The method makes use of statically admissible stress field based on a linear elastic finite element analysis to estimate the limit loads. The method is applied to a number of mechanical component configurations and the results compare well with those obtained by the corresponding elastic-plastic finite element analyses results.

Reference Volume Consideration in the mα-Tangent Method Based Linear Elastic Analysis

2011 ◽  
Author(s):  
R. Adibi-Asl ◽  
M. M. Hossain ◽  
S. L. Mahmood ◽  
P. S. R. Gudimetla ◽  
R. Seshadri
Keyword(s):  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Elastic Analysis ◽  
Element Analysis ◽  
Limit Loads ◽  
Linear Elastic ◽  
Reference Volume ◽  
Tangent Method

Limit loads for pressure components are determined on the basis of a single linear elastic finite element analysis by invoking the concept of kinematically active (reference) volume in the context of the “mα-tangent” method. The resulting technique enables rapid determination of lower bound limit load for pressure components by eliminating the kinematically inactive volume. This method is applied to a number of practical components with different percentages of inactive volume. The results are compared with the corresponding inelastic finite element results, or available analytical solutions.

Simplified Limit Load Estimation of Components With Cracks Using the Reference Two-Bar Structure

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Load Estimation ◽  
Element Analysis ◽  
Limit Loads ◽  
Scaling Relationships ◽  
Simple Scaling

Limit loads are determined in this paper by invoking the concept of equivalence of “static indeterminacy” that relates a multidimensional component configuration (with cracks) to a “reference two-bar structure.” Simple scaling relationships are developed that enable rapid determination of limit loads. The method is applied to different crack configurations, and the limit loads are compared with corresponding results obtained from inelastic finite element analysis.

Simplified Limit Load Determination Using the mα-Tangent Method

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
R. Seshadri ◽  
M. M. Hossain
Keyword(s):  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Limit Loads ◽  
Linear Elastic ◽  
Tangent Method ◽  
Mechanical Components

Limit load determination of mechanical components and structures by the mα-tangent method is proposed herein. The proposed technique is a simplified method that enables rapid determination of limit loads for a general class of mechanical components and structures. The method makes use of statically admissible stress field based on a linear elastic finite element analysis to estimate the limit loads. The method is applied to a number of mechanical component configurations and the results compare well with those obtained by the corresponding elastic-plastic finite element analyses results.

scholarly journals Stiffness Estimation and Equivalence of Boundary Conditions in FEM Models

2021 ◽  
Vol 11 (4) ◽  
pp. 1482
Author(s):  
Róbert Huňady ◽  
Pavol Lengvarský ◽  
Peter Pavelka ◽  
Adam Kaľavský ◽  
Jakub Mlotek
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Boundary Conditions ◽  
Model Updating ◽  
Element Model ◽  
Computational Time ◽  
Stiffness Coefficients ◽  
First Case ◽  
Numerical Approaches

The paper deals with methods of equivalence of boundary conditions in finite element models that are based on finite element model updating technique. The proposed methods are based on the determination of the stiffness parameters in the section plate or region, where the boundary condition or the removed part of the model is replaced by the bushing connector. Two methods for determining its elastic properties are described. In the first case, the stiffness coefficients are determined by a series of static finite element analyses that are used to obtain the response of the removed part to the six basic types of loads. The second method is a combination of experimental and numerical approaches. The natural frequencies obtained by the measurement are used in finite element (FE) optimization, in which the response of the model is tuned by changing the stiffness coefficients of the bushing. Both methods provide a good estimate of the stiffness at the region where the model is replaced by an equivalent boundary condition. This increases the accuracy of the numerical model and also saves computational time and capacity due to element reduction.

Use of DNVGL-RP-C203 for Determining the Fatigue Capacity of Connectors

2021 ◽  
Author(s):  
Anthony Muff ◽  
Anders Wormsen ◽  
Torfinn Hørte ◽  
Arne Fjeldstad ◽  
Per Osen ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Testing ◽  
Experimental Testing ◽  
High Strength ◽  
Element Model ◽  
Fatigue Analysis ◽  
Full Scale ◽  
The Finite Element Model

Abstract Guidance for determining a S-N based fatigue capacity (safe life design) for preloaded connectors is included in Section 5.4 of the 2019 edition of DNVGL-RP-C203 (C203-2019). This section includes guidance on the finite element model representation, finite element based fatigue analysis and determination of the connector design fatigue capacity by use of one of the following methods: Method 1 by FEA based fatigue analysis, Method 2 by FEA based fatigue analysis and experimental testing and Method 3 by full-scale connector fatigue testing. The FEA based fatigue analysis makes use of Appendix D.2 in C203-2019 (“S-N curves for high strength steel applications for subsea”). Practical use of Section 5.4 is illustrated with a case study of a fatigue tested wellhead profile connector segment test. Further developments of Section 5.4 of C203-2019 are proposed. This included acceptance criteria for use of a segment test to validate the FEA based fatigue analysis of a full-scale preloaded connector.

Sign in / Sign up

Export Citation Format

Share Document