A hygrothermo-mechanical model for wood: Part B. Parametric studies and application to wood welding

Abstract The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygric, thermal and mechanical (HTM) behavior of wood are considered in a coupled manner. A fully coupled poromechanical approach has been used to perform a parametric study on wood HTM behavior, and the results have been validated with neutron imaging measurements on a moist wood specimen exposed to high temperature. Further, HTM behavior of wood during welding has been simulated by the model. For such a simulation, proper material properties are needed, as some of them, for example thermal conductivity, have a significant influence on the local and temporal behavior of the material.

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A hygrothermo-mechanical model for wood: part A. Poroelastic formulation and validation with neutron imaging

Holzforschung ◽

10.1515/hf-2014-0189 ◽

2015 ◽

Vol 69 (7) ◽

pp. 825-837 ◽

Cited By ~ 3

Author(s):

Saeed Abbasion ◽

Jan Carmeliet ◽

Marjan Sedighi Gilani ◽

Peter Vontobel ◽

Dominique Derome

Keyword(s):

High Temperature ◽

Moisture Content ◽

Mechanical Model ◽

Wood Sample ◽

Industrial Process ◽

Neutron Imaging ◽

Correct Prediction ◽

Environmental Loading ◽

Wood Part ◽

Fully Coupled

Abstract The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygrothermal and mechanical (HTM) behavior of wood is considered in a coupled manner. A fully coupled poromechanical approach is proposed and validated with neutron imaging measurements of moist wood specimens exposed to high temperature. This paper demonstrates that a coupled HTM approach adequately captures the variations of temperature, moisture content, and dimensions that result in a moist wood sample exposed to one-side heating.

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The Role of Water in the Hygro-Thermo-Mechanical Behavior of Wood

Volume 9: Mechanics of Solids, Structures and Fluids ◽

10.1115/imece2013-65101 ◽

2013 ◽

Author(s):

Dominique Derome ◽

Alessandra Patera ◽

Ahmad Rafsanjani ◽

Saeed Abbasion ◽

Jan Carmeliet

Keyword(s):

Water Sorption ◽

Cellular Structure ◽

Industrial Process ◽

Correct Prediction ◽

Biological Origin ◽

Environmental Loading ◽

Comprehensive Framework ◽

Fully Coupled

Wood, due to its biological origin, has the capacity to interact with water. Sorption/desorption of moisture is accompanied with swelling/shrinkage and softening/hardening of its stiffness. The correct prediction of the behavior of wood components undergoing environmental loading or industrial process requires that the hygric, thermal and mechanical (HTM) behavior of wood are considered in a coupled manner. In addition, we propose a comprehensive framework using a fully coupled poromechanical approach, where its multiscale implementation provides the capacity to take into account, directly, the exact geometry of wood cellular structure, using computational homogenization. A hierarchical model is used to take into account the subcellular composite-like organization of the material. Such advanced modeling requires high resolution experimental data for the appropriate determination of inputs and for its validation.

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A Meso-Electro-Mechanical Model for PMN-PT-BT Ceramics Behavior

10.1115/imece2001/ad-23747 ◽

2001 ◽

Author(s):

Jinghong Fan

Keyword(s):

Phase Transition ◽

Mechanical Model ◽

Three Dimensional ◽

Constitutive Behavior ◽

Rate Equations ◽

State Variables ◽

Empirical Relationships ◽

Nonlinear Hysteresis ◽

Fully Coupled ◽

Maximum Permittivity

Abstract A three-dimensional, meso-electro-mechanical model has been formulated for description of PMN-PT-BT ceramics. Unlike the experimentally fit models and phenomenological models which are based on state variables and/or empirical relationships, this fully coupled, computational mesomechanics model for polycrystalline PMN-PT-BT ceramics is developed based on considerations of constitutive behavior of single crystals. Specifically, domain wall nucleation and evolution rate equations are proposed in this work to describe the nonlinear hysteresis behavior of these ceramics near the phase transition temperature with maximum permittivity.

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Theoretical Meso-Model of Al2O3/ZrO2 Ceramic Response under Compression

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.601.92 ◽

2014 ◽

Vol 601 ◽

pp. 92-95

Author(s):

Tomasz Sadowski ◽

Liviu Marsavina

Keyword(s):

Grain Boundary ◽

Material Properties ◽

Mechanical Model ◽

Constitutive Relations ◽

Ceramic Composites ◽

Theoretical Modeling ◽

Polycrystalline Structure ◽

Two Phase

This paper presents theoretical modeling of two-phase ceramic composites subjected to compression. The meso-mechanical model allows for inclusion of all microdefects in the polycrystalline structure that exists at the grain boundary interfaces and inside the grains. The constitutive relations for the Al2O3/ZrO2composite with the gradual degradation of the material properties due to different defects development were formulated.

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A Fully Coupled Thermo-Hydro-Mechanical Model For Methane Hydrate Reservoir Simulations

Advances in Environmental Geotechnics ◽

10.1007/978-3-642-04460-1_37 ◽

2010 ◽

pp. 455-461 ◽

Cited By ~ 1

Author(s):

Huo-Lang Fang

Keyword(s):

Mechanical Model ◽

Methane Hydrate ◽

Reservoir Simulations ◽

Hydrate Reservoir ◽

Fully Coupled

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Investigation of Point Load Index Using Novel Discrete Based Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.846.348 ◽

2016 ◽

Vol 846 ◽

pp. 348-353

Author(s):

Somayeh Behraftar ◽

Joshua Heslin ◽

S. Galindo Torres ◽

Alexander Scheuermann

Keyword(s):

Compressive Strength ◽

Material Properties ◽

Mechanical Model ◽

Rock Type ◽

Correlation Factor ◽

Point Load ◽

Load Test ◽

Point Load Index ◽

Bonded Particles ◽

The One

In this study, a micro-mechanical model is developed to study the correlation of the point load index in rocks with uniaxial compressive strength (UCS) tests. The model is represented by an array of bonded particles simulated by a novel discrete based model, which was introduced by the authors previously. The point load test (PLT) is performed in the field on rock samples to classify and estimate the UCS of a rock type via the index-to-strength correlation factor k. Numerical analyses, such as the one presented in this work, will serve to close the knowledge gap concerning the correlation between k, UCS and other material properties of rocks.

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Neutron Imaging Methods for the Investigation of Energy Related Materials (Fuel Cells, Battery, Hydrogen Storage and Nuclear Fuel)

MRS Proceedings ◽

10.1557/proc-1262-w05-01 ◽

2010 ◽

Vol 1262 ◽

Cited By ~ 1

Author(s):

Eberhard Helmar Lehmann ◽

Pierre Oberholzer ◽

Pierre Boillat

Keyword(s):

Hydrogen Storage ◽

Nuclear Fuel ◽

Material Properties ◽

Energy Supply ◽

Pem Fuel Cell ◽

Neutron Imaging ◽

Essential Information ◽

Non Invasive ◽

Wide Range ◽

Li Battery

AbstractThis article underlines with examples of studies for energy related materials and processes how important and useful the technique of neutron imaging can be for our future energy supply. With the help of the particularly designed configurations for each such study it becomes possible to derive essential information for the material properties and their change in a non-invasive manner.The four mentioned examples (PEM fuel cell, Li-battery, hydrogen storage and nuclear fuel inspection) cover a very wide range of applications and demonstrate the high potential of the various used methods in neutron imaging.

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THERMOREVERSIBLE CROSS-LINKING OF RUBBER COMPOUNDS: FROM PROOF-OF-CONCEPT TOWARD AN INDUSTRIAL PROCESS

Rubber Chemistry and Technology ◽

10.5254/rct-18-82638 ◽

2018 ◽

Vol 91 (2) ◽

pp. 492-508 ◽

Cited By ~ 2

Author(s):

L. M. Polgar ◽

J. Keizer ◽

R. Blom ◽

B. Niemeijer ◽

T. de With ◽

...

Keyword(s):

Carbon Black ◽

Material Properties ◽

Industrial Process ◽

Mineral Oil ◽

Diels Alder ◽

Cross Linking ◽

Proof Of Concept ◽

Rubber Compounds ◽

Internal Mixer ◽

Batch Mixer

ABSTRACT It is demonstrated that the concept of thermoreversible cross-linking of functionalized maleic anhydride grafted ethylene–propylene (EPM-g-MA) rubber using Diels–Alder chemistry is limited neither to laboratory scale using a solvent route nor to gum rubber. The use of an internal mixer is the first step toward an industrial process, since it greatly reduces the processing time and allows for a solventless process for the furan-functionalization and subsequent bismaleimide cross-linking of EPM rubber. Practical rubber compounds were prepared by mixing thermoreversibly cross-linked EPM with carbon black and mineral oil in the same batch mixer. This resulted in reinforcement of the rubber without affecting the thermoreversible character of the cross-linking. The pendant furan groups of the (non)cross-linked EPM-g-furan interact with the carbon black filler. Finally, crystalline EPM rubber compounds were prepared, which show excellent material properties and property retention over multiple reprocessing cycles.

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A Simulation Method of Establishing Fatigue Life Distribution

Journal of Engineering for Industry ◽

10.1115/1.3438814 ◽

1976 ◽

Vol 98 (1) ◽

pp. 183-188 ◽

Cited By ~ 1

Author(s):

H. A. Elmaraghy ◽

J. N. Siddall

Keyword(s):

Fatigue Life ◽

Material Properties ◽

Digital Simulation ◽

Simulation Method ◽

Fatigue Tests ◽

Design Tool ◽

Statistical Characteristics ◽

Life Distribution ◽

Parametric Studies ◽

Life Distributions

This paper presents a Monte Carlo simulation method for fatigue failure, by which the randomness of two material properties as well as that of the applied load can be incorporated into a stochastic model using an appropriate failure criterion to predict the statistical characteristics of fatigue life under constant and random amplitude cyclic loading conditions. In this technique, both the endurance limit Se and the fatigue strength coefficient Sf′ are treated as stochastic variables. The combined effect of the randomness of Se, Sf′, and the applied stress on the statistical characteristics of fatigue lives is predicted analytically using digital simulation of fatique tests. The life distributions and their statistical characteristics are found to be in good agreement with those obtained from analyzing the experimental results, indicating that the proposed technique and the underlying assumptions and hypotheses are adequate. The suggested method is believed to be an effective, fast, and easy-to-use design tool which is suitable for use on electronic computers. It is ideal for parametric studies compared with the costly and time-consuming laboratory fatigue tests. Minimum experimental data are needed as a basis for the analysis. New results are presented which show the effect of the randomness of the loads and material properties on the randomness of fatigue life distribution.

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