Enhancement of a meso-scale material model for nonlinear elastic finite element computations of plain-woven fabric membrane structures

2018 ◽  
Vol 177 ◽  
pp. 668-681 ◽  
Author(s):  
Jan Gade ◽  
Roman Kemmler ◽  
Michael Drass ◽  
Jens Schneider
Keyword(s):  
Finite Element ◽  
Material Model ◽  
Woven Fabric ◽  
Membrane Structures ◽  
Nonlinear Elastic ◽  
Meso Scale

Strength Simulation of Woven Fabric Composite Materials With Material Nonlinearity Using Micromechanics Based Model

2000 ◽  
Author(s):  
A. Tabiei ◽  
G. Song ◽  
Y. Jiang
Keyword(s):  
Finite Element ◽  
Shear Failure ◽  
Material Model ◽  
Failure Criteria ◽  
Woven Fabric ◽  
Woven Composites ◽  
Explicit Finite Element ◽  
Representative Cell ◽  
Pure Matrix ◽  
Transverse Failure

Abstract The objective of the current investigation is to predict failure strength of woven composites, which considers the two-dimensional extent of woven fabric, based on micro-mechanics. The formulation has an interface with nonlinear finite element codes. At each load increment, global stresses and strains are communicated to the representative cell and subsequently distributed to each subcell. Once stresses and strains are associated to a subcell they can be distributed to each constituent of the subcell (i.e. fill, warp, and resin). Consequently micro-failure criteria (MFC) are defined for each constituents of a subcell and the proper stiffness degradation is modeled. Different stages of failure such as warp transverse failure, fill transverse failure, failure of pure matrix in longitudinal and shear, shear failure in fill and warp, and fiber in fill and warp in longitudinal tension are considered. Good correlation is observed between the predicted and the experimental results presented in the published literature. This material model is suitable for implicit failure analysis under static loads and is being modified for explicit finite element codes to deal with problems such as crashworthiness and impact.

scholarly journals An Approach for Material Model Identification of a Composite Coating Using Micro-Indentation and Multi-Scale Simulations

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 92
Author(s):  
Pouya Shojaei ◽  
Riccardo Scazzosi ◽  
Mohamed Trabia ◽  
Brendan O’Toole ◽  
Marco Giglio ◽  
...  
Keyword(s):  
Finite Element ◽  
Model Comparison ◽  
Plastic Material ◽  
Composite Coatings ◽  
Material Model ◽  
Scale Model ◽  
Indentation Testing ◽  
Micro Scale ◽  
Micro Indentation ◽  
Meso Scale

While deposited thin film coatings can help enhance surface characteristics such as hardness and friction, their effective incorporation in product design is restricted by the limited understanding of their mechanical behavior. To address this, an approach combining micro-indentation and meso/micro-scale simulations was proposed. In this approach, micro-indentation testing was conducted on both the coating and the substrate. A meso-scale uniaxial compression finite element model was developed to obtain a material model of the coating. This material model was incorporated within an axisymmetric micro-scale model of the coating to simulate the indentation. The proposed approach was applied to a Ti/SiC metal matrix nanocomposite (MMNC) coating, with a 5% weight of SiC nanoparticles deposited over a Ti-6Al-4V substrate using selective laser melting (SLM). Micro-indentation testing was conducted on both the Ti/SiC MMNC coating and the Ti-6Al-4V substrate. The results of the meso-scale finite element indicated that the MMNC coating can be represented using a bi-linear elastic-plastic material model, which was incorporated within an axisymmetric micro-scale model. Comparison of the experimental and micro-scale model results indicated that the proposed approach was effective in capturing the post-indentation behavior of the Ti/SiC MMNC coating. This methodology can also be used for studying the response of composite coatings with different percentages of reinforcements.

A Non Linear Finite Element Model to Analyse the Dynamics of Subsea Lifting Operation Using Synthetic Cables

2020 ◽  
Author(s):  
Evandro Souto Carobino ◽  
Renato Pavanello ◽  
Rodrigo Batista Tommasini ◽  
Debora Junqueira Fonseca ◽  
Leonardo de Oliveira Carvalho
Keyword(s):  
Finite Element ◽  
Material Model ◽  
Element Model ◽  
Nonlinear Material ◽  
Sea Waves ◽  
Element Mesh ◽  
Equivalent Linear ◽  
The Time Domain ◽  
Nonlinear Elastic ◽  
Predictor Corrector

Abstract In the context of subsea lifting many equipment and strategies are employed in order to avoid dynamic instabilities and complex mechanical behaviors during the installation procedures. One of those strategies is the use of synthetic cables to reduce the total sustained weight on the crane and to shift the resonance frequency of the system, leading to reductions of fails risks. This work presents a numerical model intended to predict the dynamic behavior of a cable-equipment system under the influence of the sea waves. The cable is discretized in a finite element mesh which accounts for a nonlinear material model for the elasticity of the cable. The nonlinear elastic law uses a polynomial function to represent the force on the cable as a function of the strain, being able to predict the variation of the stiffness for different load conditions. Further, hydrodynamic forces are considered acting on the equipment and are modeled via Morison’s equation, which introduces a quadratic nonlinear forcing term. The equation of motion is then integrated at the time domain through a Newmark-β predictor-corrector method in order to obtain the dynamic response of the system. Furthermore, an Orcaflex model is constructed using an equivalent linear stiffness representation for the synthetic cable. The results obtained are compared, and the differences between them are highlighted for typical subsea lifting scenarios. In this case, the proposed model can predict non trivial dynamic behaviors of the system such as dependence on the amplitude of the displacement of the lifting point. It is also presented the scenarios where the equivalent linear model is accurate in comparison to the nonlinear one and how the selection of the strain point used to linearize the model affects the dynamics of the system.

Computational Micro-Mechanical Model of Composite and Flexible Woven Fabric With Fiber Reorientation

2001 ◽  
Author(s):  
Ala Tabiei ◽  
Ivelin Ivanov
Keyword(s):  
Finite Element ◽  
Impact Analysis ◽  
Material Model ◽  
Woven Fabric ◽  
Explicit Finite Element ◽  
Shear Moduli ◽  
Fiber Reorientation ◽  
Mechanical Approach ◽  
Ballistic Test ◽  
Fabric Material

Abstract This work presents a computational material model of flexible woven fabric for finite element impact analysis and simulation. The model is implemented in the nonlinear dynamic explicit finite element code LSDYNA. The material model derivation utilizes the micro-mechanical approach and the homogenization technique usually used in composite material models. The model accounts for reorientation of the yarns and the fabric architecture. The behavior of the flexible fabric material is achieved by discounting the shear moduli of the material in free state, which allows the simulation of the trellis mechanism before packing the yams. The material model is implemented into the LSDYNA code as a user defined material subroutine. The developed model and its implementation is validated using an experimental ballistic test on Kevlar® woven fabric. The presented validation shows good agreement between the simulation utilizing the present material model and the experiment.

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.

Lifetime Prediction of Tires with Regard to Oxidative Aging5

2008 ◽  
Vol 36 (1) ◽  
pp. 63-79 ◽  
Author(s):  
L. Nasdala ◽  
Y. Wei ◽  
H. Rothert ◽  
M. Kaliske
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Superposition Principle ◽  
Accelerated Aging ◽  
Material Model ◽  
Aging Behavior ◽  
Element Analysis ◽  
Material Parameters ◽  
Reaction Processes

Abstract It is a challenging task in the design of automobile tires to predict lifetime and performance on the basis of numerical simulations. Several factors have to be taken into account to correctly estimate the aging behavior. This paper focuses on oxygen reaction processes which, apart from mechanical and thermal aspects, effect the tire durability. The material parameters needed to describe the temperature-dependent oxygen diffusion and reaction processes are derived by means of the time–temperature–superposition principle from modulus profiling tests. These experiments are designed to examine the diffusion-limited oxidation (DLO) effect which occurs when accelerated aging tests are performed. For the cord-reinforced rubber composites, homogenization techniques are adopted to obtain effective material parameters (diffusivities and reaction constants). The selection and arrangement of rubber components influence the temperature distribution and the oxygen penetration depth which impact tire durability. The goal of this paper is to establish a finite element analysis based criterion to predict lifetime with respect to oxidative aging. The finite element analysis is carried out in three stages. First the heat generation rate distribution is calculated using a viscoelastic material model. Then the temperature distribution can be determined. In the third step we evaluate the oxygen distribution or rather the oxygen consumption rate, which is a measure for the tire lifetime. Thus, the aging behavior of different kinds of tires can be compared. Numerical examples show how diffusivities, reaction coefficients, and temperature influence the durability of different tire parts. It is found that due to the DLO effect, some interior parts may age slower even if the temperature is increased.

Application of the Finite Element Method in Screening of Body Turn up Heights for Radial Truck Tires

2001 ◽  
Vol 29 (3) ◽  
pp. 186-196 ◽  
Author(s):  
X. Yan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Model ◽  
The Finite Element Method ◽  
Truck Tires ◽  
Contact Constraint ◽  
Nonlinear Mechanical ◽  
Critical Regions ◽  
Constraint Method ◽  
Element Method

Abstract A method is described to predict relative body turn up endurance of radial truck tires using the finite element method. The elastomers in the tire were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. The belt, carcass, and bead were modeled by an equivalent orthotropic material model. The contact constraint of a radial tire structure with a flat foundation and rigid rim was treated using the variable constraint method. Three groups of tires with different body turn up heights under inflation and static footprint loading were analyzed by using the finite element method. Based on the detail analysis for stress analysis parameters in the critical regions in the tires, the relative body turn up edge endurance was predicted.

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