A Hybrid Approach for Quantifying the Winding Process and Material Effects on Sheet Coil Deformation

2004 ◽  
Vol 126 (3) ◽  
pp. 303-313 ◽  
Author(s):  
Shunping Li ◽  
Jian Cao
Keyword(s):  
Hybrid Approach ◽  
Material Model ◽  
Element Model ◽  
Equivalent Material ◽  
Analysis Model ◽  
Engineering Design Process ◽  
Radial Stiffness ◽  
Gravitational Loading ◽  
Laminate Sheet ◽  
Winding Tension

Excessive coil deformation can complicate normal handling of a wound or rolled coil, cause difficulties in mass production, and introduce undesirable variations in the subsequent manufacturing processes. Four critical factors for coil deformation have been identified, i.e., radial stiffness of the coil material, winding tension, stiffness of the core which supports the coil, and lubrication. In this paper, we advance the understanding of coil deformation by developing an equivalent material model based on the internal stress distribution obtained from a two-dimensional winding-analysis model. The proposed material model is then implemented in a multi-layer finite element model to study the coil deformation under gravitational loading. This proposed framework can quantify the contribution of each factor in the coil deformation and thereby provide more scientific base in the engineering design process. The approach is used to analyze the deformation of laminate sheet coils.

A Hybrid Approach to Test-Analysis-Model Development for Large Space Structures

1991 ◽  
Vol 113 (3) ◽  
pp. 325-332 ◽  
Author(s):  
D. C. Kammer
Keyword(s):  
Model Development ◽  
Hybrid Approach ◽  
Element Model ◽  
Space Structure ◽  
Mode Shapes ◽  
Analysis Model ◽  
Large Space ◽  
Test Analysis ◽  
Test Mode ◽  
Analysis Mode

A new finite element model (FEM) reduction method is presented for use in the generation of Test-Analysis-Models (TAM) in test-analysis correlation. The method addresses the concern that some current TAM methodologies, specifically the Modal TAM, are overly sensitive to differences between test mode shapes and analysis mode shapes. This sensitivity can result in large off-diagonal terms within the orthogonality and cross-orthogonality matrices used for test-analysis mode shape correlation. It has been hypothesized that the sensitivity is due to the Modal TAM’s poor representation of residual mode shapes and frequencies which are modes that are not targeted for identification. In many cases it has been observed that the less accurate static TAM often gives better off-diagonal correlation results. A new Hybrid TAM methodology is developed to combine the exact representation of the FEM target modes from the Modal TAM with the more accurate static TAM representation of the residual modes. The superior residual dynamics representation of the Hybrid TAM is demonstrated for both a simple spacecraft and a much more detailed representation of a Large Space Structure. Simulated test-analysis correlation results are presented for both examples where test mode shapes are represented by FEM target modes with noise modeled as a random linear combination of all FEM modes. Analysis indicates that the Hybrid TAM’s improved residual representation results in reduced sensitivity of the test-analysis correlation to model error.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Assessment of 3D Linear Elastic Masonry-Like Vaulted Structures

2019 ◽  
Vol 817 ◽  
pp. 50-56
Author(s):  
Deborah Briccola ◽  
Matteo Bruggi ◽  
Alberto Taliercio
Keyword(s):  
Material Model ◽  
Equivalent Material ◽  
Technical Literature ◽  
Linear Elastic ◽  
Novel Approach ◽  
Out Of Plane ◽  
Minimization Procedure ◽  
Live Loads ◽  
Historical Masonry ◽  
No Tension Material

A novel approach is adopted to assess the static behavior of vaulted structures, such as cantilevered masonry stairs, assuming a linear elastic no-tension material model. Masonry is substituted by an equivalent orthotropic material whose elastic properties vary locally and with a negligible stiffness where tensile strain occurs. In order to recover a tension-free state of stress, an energy-based minimization procedure is carried out to establish the distribution and the orientation of the equivalent material for a given compatible load. The capability of the approach in defining purely compressive stress solutions in masonry walls under dead load and both in-plane and out-of-plane live loads has already been assessed. A meaningful application to a cantilevered masonry stair is here presented; the results are in good agreement with those available in the technical literature on historical masonry constructions.

scholarly journals Thermo-mechanical analysis of linear welding stage in friction stir welding - influence of welding parameters

2021 ◽  
pp. 186-186
Author(s):  
Darko Veljic ◽  
Marko Rakin ◽  
Aleksandar Sedmak ◽  
Nenad Radovic ◽  
Bojan Medjo ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Heat Generation ◽  
Welding Speed ◽  
Reaction Force ◽  
Material Model ◽  
Element Model ◽  
Welding Parameters ◽  
Al Alloy ◽  
Friction Stir ◽  
Fsw Parameters

The influence of friction stir welding (FSW) parameters on thermo-mechanical behaviour of the material during welding is analysed. An aluminium alloy is considered (Al 2024 T351), and different rotating speed and welding speed are applied. Finite element model consists of the plate (Al alloy), backing plate and welding tool, and it is formed and solved in software package Simulia Abaqus. The influence of the welding conditions on material behaviour is taken into account by application of the Johnson-Cook material model. The rotation of the tool affects the results: if increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, the plastic deformation of the material, is negligibly changed. When the welding speed is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming increases. Combined, these two effects cause small change of the total heat generation. For the same welded joint length, the plate welded by lower speed will be heated more intensively. The changes of the heat generation influence both the temperature field and reaction force, which are also considered.

Experimental and numerical investigation of damping in a hybrid automotive damper combining viscous and multiple-impact mechanisms

2021 ◽  
pp. 107754632110381
Author(s):  
Yousif Badri ◽  
Sadok Sassi ◽  
Mohammed Hussein ◽  
Jamil Renno
Keyword(s):  
Viscous Fluid ◽  
Frequency Response ◽  
Piecewise Linear ◽  
Material Model ◽  
Element Model ◽  
Fe Model ◽  
Combination Process ◽  
Hybrid Damper ◽  
Multiple Impact ◽  
Steel Balls

One of the least investigated approaches in passive vibration control is the possibility of combining different types of dampers that use different damping principles. Such a combination process, if wisely designed and implemented, has the potential to increase the damping performance and extend the damper’s application. The primary purpose of this work is to experimentally and numerically investigate the damping behavior of a novel Fluid-Impact Hybrid Damper. This damper combines a conventional Viscous Fluid Damper with a Particle-Impact Damper. The Fluid-Impact Hybrid Damper comprises a 3D-printed plastic box attached to the Viscous Fluid Damper’s moving rod and filled with stainless steel balls. An experimental setup was designed to drive the Viscous Fluid Damper’s rod into harmonic oscillations at different frequencies (1, 2, 4, 6, and 8 Hz). The number of balls was changed three times (5, 10, and 15) to assess the effect of this parameter on the damping performance of the Fluid-Impact Hybrid Damper. A finite element model of the Fluid-Impact Hybrid Damper was developed using LS-Dyna explicit simulation program. The objective of the FE model is to investigate the elastoplastic balls-box collisions using a piecewise-linear plasticity material model. For both the experimental and numerical results, the Frequency Response Function was considered as the main comparison component for a set of force-independent results. The measured Frequency Response Functions showed a noticeable reduction in amplitude at the system’s natural frequency (2 Hz), with an acceptable accuracy between the two approaches.

scholarly journals Seismic Response Analysis of Pier considering Durability Damage Repair

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yan Liang ◽  
Liangliang Li ◽  
Ruimin Mao ◽  
Xiaoye Shi
Keyword(s):  
Seismic Performance ◽  
Steel Corrosion ◽  
Element Model ◽  
Response Analysis ◽  
Reinforced Concrete Structure ◽  
Analysis Model ◽  
Bond Slip ◽  
Damage Repair ◽  
Bridge Structures ◽  
Material Durability

At present, most of the research studies on the seismic performance of the durability degraded reinforced concrete structure only consider the influence of a single factor. This paper comprehensively considers the factors such as concrete carbonization, steel corrosion, and bond slip performance degradation caused by other durability factors and durability damage repair and studies the influence of the above factors on the seismic performance of bridge structures. Based on the finite element model considering the bond slip and the material parameters of time-varying durability damage, the seismic performance analysis model of the pier is established considering material durability damage repair in different service periods. Then, the effect of material durability damage repair on the seismic performance of the pier is examined. The results show that the displacement of the pier top increases, the curvature of the pier bottom decreases, and the moment-curvature curve pinching phenomenon is further evident when considering the bond slip. When considering the durability damage repair of materials, the curvature considerably decreases (the maximum value is approximately 16.04%) with the extension of the service time of the bridge, and the pier damage is substantially reduced.

Fully Coupled Finite Element Analysis of an Automatic Multi-Stage Cold Forging Process

2020 ◽  
Vol 311 ◽  
pp. 88-93
Author(s):  
Jong Bok Byun ◽  
Hyun Joon Lee ◽  
Jong Bok Park ◽  
Il Dong Seo ◽  
Man Soo Joun
Keyword(s):  
High Strength ◽  
Material Model ◽  
Die Design ◽  
Cold Forging ◽  
Complete Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Forging Process ◽  
Multi Stage ◽  
Analysis Scheme

In this paper, non-isothermal analysis of an automatic multi-stage cold forging process of a ball-stud is conducted using a new material model which is a closed form function of strain, temperature and strain rate covering low and warm temperatures for high-strength stainless steel SUS304. An assembled die structural analysis scheme is employed for revealing the detailed die stresses, which is of great importance for process and die design for metal forming of the materials with high strengths. Die elastic deformation is dealt with to predict final geometries of material with higher accuracy. A complete analysis model is proposed to be used for optimal design of process and die designs in automatic multi-stage cold forging of high-strength materials.

Discontinuous failure in micropolar elastic-degrading models

2017 ◽  
Vol 27 (10) ◽  
pp. 1482-1515 ◽  
Author(s):  
Lapo Gori ◽  
Samuel S Penna ◽  
Roque L da Silva Pitangueira
Keyword(s):  
Material Model ◽  
Element Model ◽  
Additional Material ◽  
Micropolar Continuum ◽  
Starting Point ◽  
Localization Analysis ◽  
Acceleration Waves ◽  
Micropolar Media ◽  
Waves Propagation ◽  
Bending Length

The present paper investigates the phenomenon of discontinuous failure (or localization) in elastic-degrading micropolar media. A recently proposed unified formulation for elastic degradation in micropolar media, defined in terms of secant tensors, loading functions and degradation rules, is used as a starting point for the localization analysis. Well-known concepts on acceleration waves propagation, such as the Maxwell compatibility condition and the Fresnel–Hadamard propagation condition, are derived for the considered material model in order to obtain a proper failure indicator. Peculiar problems are investigated analytically in details, in order to evaluate the effects on the onset of localization of two of the additional material parameters of the micropolar continuum, the Cosserat’s shear modulus and the internal bending length. Numerical simulations with a finite element model are also presented, in order to show the regularization behaviour of the micropolar formulation on the pathological effects due to the localization phenomenon.

Metamodeling Development for Vehicle Frontal Impact Simulation

2001 ◽  
Author(s):  
R. J. Yang ◽  
N. Wang ◽  
C. H. Tho ◽  
J. P. Bobineau ◽  
B. P. Wang
Keyword(s):  
Response Surface ◽  
Impact Analysis ◽  
Hybrid Approach ◽  
Latin Hypercube Sampling ◽  
Element Model ◽  
Least Square ◽  
Frontal Impact ◽  
Response Surface Methods ◽  
Moving Least Square ◽  
Highly Nonlinear

Abstract Response surface methods or metamodels are commonly used to approximate large engineering systems. This paper presents a new metric for evaluating a response surface method or a metamodeling technique. Five response surface methods are studied: Stepwise Regression, Moving Least Square, Kriging, Multiquadratic, and Adaptive and Interactive Modeling System. A real world frontal impact design problem is used as an example, which is a complex, highly nonlinear, transient, dynamic, large deformation finite element model. The optimal Latin Hypercube Sampling method is used to distribute the sampling points uniformly over the entire design space. The Root Mean Square Error is used as the error indicator to study the accuracy and convergence rate of the metamodels for this vehicle impact analysis. A hybrid approach/strategy for selecting the best metamodels of impact responses is proposed.

A Virtual Model for Aluminum Hot Forging Using an Artificial Neural Network Material Model Within Finite Element Analysis

2005 ◽  
Author(s):  
B. Scott Kessler ◽  
A. Sherif El-Gizawy
Keyword(s):  
Finite Element ◽  
Effective Means ◽  
Hot Forging ◽  
Material Model ◽  
Element Model ◽  
Operating Conditions ◽  
Element Analysis ◽  
Preliminary Model ◽  
Wide Range ◽  
Artificial Neural

The accuracy of a finite element model for design and analysis of a metal forging operation is limited by the incorporated material model’s ability to predict deformation behavior over a wide range of operating conditions. Current rheological models prove deficient in several respects due to the difficulty in establishing complicated relations between many parameters. More recently, artificial neural networks (ANN) have been suggested as an effective means to overcome these difficulties. In the present work, a previously developed ANN with the ability to determine flow stresses based on strain, strain rate, and temperature is incorporated with finite element code. Utilizing this linked approach, a preliminary model for forging an aluminum wheel is developed. This novel method, along with a conventional approach, is then measured against the forging process as it is currently performed in actual production.

Sign in / Sign up

Export Citation Format

Share Document