Mesh Convergence Studies for Hexahedral Elements Developed by the ASME Special Working Group on Computational Modeling

2013 ◽  
Author(s):  
Chi-Fung Tso ◽  
David P. Molitoris ◽  
Michael Yaksh ◽  
Spencer Snow ◽  
Doug Ammerman ◽  
...  
Keyword(s):  
Finite Element ◽  
Computational Modeling ◽  
Finite Element Model ◽  
Working Group ◽  
Element Model ◽  
Plastic Strains ◽  
Hexahedral Elements ◽  
Special Working ◽  
Special Working Group

The ASME Special Working Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of element convergence studies that can aid designers in establishing the mesh refinement requirements necessary to achieve accurate results for a variety of different element types in regions of high plastic strain. These convergence studies will also aid reviewers in evaluating the quality of a finite element model and the apparent accuracy of its results. In this paper, the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA hexahedral elements using both reduced and selectively reduced integration. Three loading levels are considered; the first maintains strains within the elastic range, the second induces moderate plastic strains, and the third produces large deformations and large plastic strains.

Mesh Convergence Studies for Thick Shell Elements Developed by the ASME Special Working Group on Computational Modeling

2013 ◽  
Author(s):  
David P. Molitoris ◽  
Gordon S. Bjorkman ◽  
Chi-Fung Tso ◽  
Michael Yaksh
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Working Group ◽  
Element Model ◽  
Thick Shell ◽  
Shell Elements ◽  
Special Working ◽  
Special Working Group

The ASME Special Working Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of element convergence studies that can aid designers in establishing the mesh refinement requirements necessary to achieve accurate results for a variety of different element types in regions of high plastic strain. These convergence studies will also aid reviewers in evaluating the quality of a finite element model and the apparent accuracy of its results. In this paper, the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA thick shell elements using both reduced and selectively reduced integration. A large load is applied to produce large deformations and large plastic strains in the beam. The deformation and plastic strain results are then compared to similar results obtained using thin shell elements and hexahedral elements for the beam mesh.

Mesh Convergence Studies for Thin Shell Elements Developed by the ASME Task Group on Computational Modeling

2011 ◽  
Author(s):  
Gordon S. Bjorkman ◽  
David P. Molitoris
Keyword(s):  
Finite Element ◽  
Computational Modeling ◽  
Finite Element Model ◽  
Thin Shell ◽  
Element Model ◽  
Task Group ◽  
Plastic Strains ◽  
Shell Elements ◽  
Explicit Dynamics

The ASME Task Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of element convergence studies that can aid designers in establishing the mesh refinement requirements necessary to achieve accurate results for a variety of different elements types in regions of high plastic strain. These convergence studies will also aid reviewers in evaluating the quality of a finite element model and the apparent accuracy of its results. In this paper the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA thin shell elements using both reduced and full integration. Three loading levels are considered; the first maintains strains within the elastic range, the second induces moderate plastic strains, and the third produces large deformations and large plastic strains.

Hourglass Control Convergence Studies for Hexahedral Elements Developed by the ASME Special Working Group on Computational Modeling

2013 ◽  
Author(s):  
David P. Molitoris ◽  
Gordon S. Bjorkman ◽  
Chi-Fung Tso ◽  
Michael Yaksh
Keyword(s):  
Finite Element ◽  
Computational Modeling ◽  
Working Group ◽  
Guidance Document ◽  
Reduced Integration ◽  
Explicit Dynamics ◽  
Hexahedral Elements ◽  
Hourglass Control ◽  
Special Working ◽  
Special Working Group

The ASME Special Working Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of convergence studies that demonstrates the effect of hourglass control settings on solution convergence for reduced integration elements. These convergence studies will demonstrate the importance of selecting an appropriate hourglass control setting to achieve accurate results for large deformation simulations using reduced integration elements. In this paper, the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA reduced integration hexahedral elements using different hourglass control settings. A large load is applied to produce large deformations and large plastic strains in the beam.

The Finite Element Analysis on the Compression Splicing Position of Strain Clamp in Guy Tower

2014 ◽  
Vol 680 ◽  
pp. 249-253
Author(s):  
Zhang Qi Wang ◽  
Jun Li ◽  
Wen Gang Yang ◽  
Yong Feng Cheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
Equivalent Stress ◽  
Element Model ◽  
Element Analysis ◽  
Elastic Plastic ◽  
The Finite Element Analysis

Strain clamp is an important connection device in guy tower. If the quality of the compression splicing position is unsatisfied, strain clamp tends to be damaged which may lead to the final collapse of a guy tower as well as huge economic lost. In this paper, stress distribution on the compressible tube and guy cable is analyzed by FEM, and a large equivalent stress of guy cable is applied to the compression splicing position. During this process, a finite element model of strain clamp is established for guy cables at compression splicing position, problems of elastic-plastic and contracting are studied and the whole compressing process of compressible position is simulated. The guy cable cracks easily at the position of compressible tube’s port, the inner part of the compressible tube has a larger equivalent stress than outside.

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

The Technology of Flexible Blank Holder Forming and the Study of its Numerical Simulation

2014 ◽  
Vol 490-491 ◽  
pp. 776-780
Author(s):  
Lian Cheng Li ◽  
Ming Zhe Li ◽  
Xiao Wei Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thickness Distribution ◽  
Element Model ◽  
Spring Back ◽  
Blank Holder ◽  
Distribution Parameters ◽  
Stress And Strain Distribution ◽  
The Finite Element Model

Abstract. In this paper, we have discussed the principle of the flexible blank holder forming ( FBHF) technology, and established the finite element model of medal deep drawing process based on FBHF. Then we have discussed the FBHF technology by analyzing the system of finite element model. By simulating the forming of rectangular box, we can conclude that FBHF technology will have a greater advantage when the depth of stamping forming is much deeper. We have also compared the thickness distribution parameters, wrinkling parameters, and spring back parameters of rigid blank holder forming parts with FBHF parts. The result shows that the forming parts of FBHF technology has uniform stress and strain distribution, small spring back, the quality of inhibiting wrinkling, crack and other defects.

Torsional Vibrations in Turbogenerators Due to Network Disturbances

1990 ◽  
Vol 112 (3) ◽  
pp. 312-320 ◽  
Author(s):  
P. Schwibinger ◽  
R. Nordmann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Degrees Of Freedom ◽  
Element Model ◽  
Torsional Vibrations ◽  
The Finite Element Method ◽  
The Past ◽  
Turbine Generators ◽  
The Finite Element Model

Large steam-turbine generators in operation may be stimulated to torsional vibrations by dynamic moments at the generator due to electrical system transients. The induced torsional stresses in the shaft have drawn growing attention over the past few years. To solve the torsional vibration problem the turbogenerator shaft is modelled by the finite element method. This paper presents the results for a 600 MW turbogenerator set. To verify the quality of the used finite element model measurements were carried out and compared with the analytical results. For some applications it is desirable to have a torsional model with a reduced number of degrees of freedom, which reproduces the finite element model only in the lower eigenfrequencies and modes. This paper describes a method on how to find the most accurate reduced torsional model with discrete masses and springs from the finite element model.

A Human Finite Element Model for Human-Cushion Interface Pressure Research

2013 ◽  
Vol 291-294 ◽  
pp. 2715-2718
Author(s):  
Hao Chen ◽  
Fang Wang ◽  
Jian Guo Zhang ◽  
Yan Ping Guo ◽  
Hai Yan Song
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Biomechanical Analysis ◽  
Human Model ◽  
Interface Pressure ◽  
Hexahedral Elements ◽  
Mechanical Experiment ◽  
The Finite Element Model

The aim of the present work was to develop a lain-human finite element model for cushion design to prevent bedsore by performing biomechanical analysis on interface pressure. The geometric data of the human was obtained by laser scans. The finite element model was composed of solid hexahedral elements. The material of the bed cushions was obtained according to the mechanical experiment. The human model was validated by comparing the simulation result with the experimental data. The validated finite element model could be used to facilitate, accelerate and economize the process of design of cushion.

scholarly journals Finite Element Modellingand Simulations of Piezoelectric Actuators Responses with Uncertainty Quantification

Computation ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 60 ◽  
Author(s):  
Vinh-Tan Nguyen ◽  
Pankaj Kumar ◽  
Jason Leong
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Uncertainty Quantification ◽  
Composite Plate ◽  
Piezoelectric Materials ◽  
Three Dimensional ◽  
Piezoelectric Actuators ◽  
Element Model ◽  
Design Parameters ◽  
Hexahedral Elements

Piezoelectric structures are widely used in engineering designs including sensors, actuators, and energy-harvesting devices. In this paper, we present the development of a three-dimensional finite element model for simulations of piezoelectric actuators and quantification of their responses under uncertain parameter inputs. The implementation of the finite element model is based on standard nodal approach extended for piezoelectric materials using three-dimensional tetrahedral and hexahedral elements. To account for electrical-mechanical coupling in piezoelectric materials, an additional degree of freedom for electrical potential is added to each node in those elements together with their usual mechanical displacement unknowns. The development was validated with analytical and experimental data for a range of problems from a single-layer piezoelectric beam to multiple layer beams in unimorph and bimorph arrangement. A more detailed analysis is conducted for a unimorph composite plate actuator with different design parameters. Uncertainty quantification was also performed to evaluate the sensitivity of the responses of the piezoelectric composite plate with an uncertain input of material properties. This sheds light on understanding the variations in reported responses of the device; at the same time, providing extra confidence to the numerical model.

Numerical Analysis and Research on the Profile Bending

2014 ◽  
Vol 608-609 ◽  
pp. 93-97
Author(s):  
Chao Zhang ◽  
Lin Long ◽  
Shang Yuan Guo
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Element Model ◽  
Short Introduction ◽  
Basic Principles ◽  
Technical Parameters ◽  
Loading Modes ◽  
The Finite Element Model

This paper establishes a finite element model to analyze the effect of different loading modes and technical parameters on quality of profile bending molding. This paper firstly gives a short introduction of the technique, basic principles and loading modes of profile stretch molding. The process of aluminum stretch molding and the snapping back phenomenon are then simulated by the finite element model. The effect of different loading modes and technical parameters on quality of profile bending molding is also analyzed. Simulations results indicate that different loading modes and technical parameters have significant influence on the quality of the profile bending molding.

Sign in / Sign up

Export Citation Format

Share Document