scholarly journals Modelling the mechanical response of urushi lacquer subject to a change in relative humidity

2012 ◽  
Vol 468 (2147) ◽  
pp. 3533-3551 ◽  
Author(s):  
X. Liu ◽  
R. D. Wildman ◽  
I. A. Ashcroft ◽  
A. E. Elmahdy ◽  
P. D. Ruiz
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Relative Humidity ◽  
Moisture Content ◽  
Thin Layer ◽  
Mechanical Response ◽  
Experimental Measurements ◽  
Environmental Conditioning ◽  
The Relationship ◽  
Good Agreement

A hygromechanical model has been developed to simulate the in-service behaviour of the natural lacquer urushi , using a phenomenological description of viscoelasticity. The material and mechanical properties were determined as a function of the relative humidity (RH), and the relationship between RH and moisture content was determined. These properties served as inputs to a finite-element-based model that was then tested against experimental measurements of the depth-averaged stresses in a thin layer of urushi deposited on a substrate and exposed to changes in the environmental conditions. Good agreement was seen between the predicted and measured behaviour. The validated model was used to investigate the spatial and temperature variation of stress in urushi films subjected to cyclic environmental conditioning.

Mechanical Response of Laminate (Glass/Epoxy) at Different Periods of Environmental Conditioning (Saturation and Ageing)

2010 ◽  
Vol 34-35 ◽  
pp. 1015-1018
Author(s):  
A. Naceri
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Glass Fiber ◽  
Mechanical Behaviour ◽  
Mechanical Response ◽  
Laminate Glass ◽  
Moisture Concentration ◽  
Environmental Conditioning ◽  
Hygrothermal Ageing ◽  
Fiber Fabric

This paper considers the analysis of the mechanical behaviour of a laminate constituted of 12 layers of glass fiber fabric/epoxy resin conditioned at different relative humidities of 0, 60 and 96% at 60 °C. The analysing of the experimental results obtained of hygrothermal ageing on the mechanical response has permited to show that the influence of the moisture concentration on the ultimate mechanical properties becomes significant and important for the composite conditioned at relative humidity of 96% to the periods I and II (state of saturation and ageing).

Modeling of Mechanical Behavior of Porous Sintered Timing Wheel in Contact with Chain Wheels

2007 ◽  
Vol 561-565 ◽  
pp. 1649-1652
Author(s):  
M. Alizadeh ◽  
H. Khorsand ◽  
Ali Shokuhfar
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Finite Element ◽  
Tensile Strength ◽  
Mechanical Behavior ◽  
Sintered Density ◽  
Fem Model ◽  
Gear Contact ◽  
The Relationship ◽  
Good Agreement

The mechanical properties of sintered timing wheel in contact with chain wheels were analysed using Finite Element Methods (FEM), in which the timing wheel is modelled as a metal powder. The mechanical properties of sintered timing wheel were investigated as a function of sintered density. Tensile strength and Young’s modulus increased with a decrease in porosity. Current methods of calculating gear contact stresses use Hertz’s equations, which were originally derived for contact between sintered timing wheel and chain wheels. The results of the 2D dimensional FEM analyses from ANSYS are presented. The relationship between relative density of P/M steels and mechanical behavior is also obtained from FEM and compared with the experimental data. Good agreement between the experimental and FEM results is observed, which demonstrates that FEM can capture the major features of the P/M steels behaviour during loading. This indicates that the FEM model is accurate.

scholarly journals Symmetric Nature of Stress Distribution in the Elastic-Plastic Range of Pinus L. Pine Wood Samples Determined Experimentally and Using the Finite Element Method (FEM)

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 39
Author(s):  
Łukasz Warguła ◽  
Dominik Wojtkowiak ◽  
Mateusz Kukla ◽  
Krzysztof Talaśka
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Stress Distribution ◽  
Moisture Content ◽  
Tool Geometry ◽  
Wood Fibers ◽  
Data Set ◽  
Plastic Deformations ◽  
Pine Wood ◽  
Elastic Plastic

This article presents the results of experimental research on the mechanical properties of pine wood (Pinus L. Sp. Pl. 1000. 1753). In the course of the research process, stress-strain curves were determined for cases of tensile, compression and shear of standardized shapes samples. The collected data set was used to determine several material constants such as: modulus of elasticity, shear modulus or yield point. The aim of the research was to determine the material properties necessary to develop the model used in the finite element analysis (FEM), which demonstrates the symmetrical nature of the stress distribution in the sample. This model will be used to analyze the process of grinding wood base materials in terms of the peak cutting force estimation and the tool geometry influence determination. The main purpose of the developed model will be to determine the maximum stress value necessary to estimate the destructive force for the tested wood sample. The tests were carried out for timber of around 8.74% and 19.9% moisture content (MC). Significant differences were found between the mechanical properties of wood depending on moisture content and the direction of the applied force depending on the arrangement of wood fibers. Unlike other studies in the literature, this one relates to all three stress states (tensile, compression and shear) in all significant directions (anatomical). To verify the usability of the determined mechanical parameters of wood, all three strength tests (tensile, compression and shear) were mapped in the FEM analysis. The accuracy of the model in determining the maximum destructive force of the material is equal to the average 8% (for tensile testing 14%, compression 2.5%, shear 6.5%), while the average coverage of the FEM characteristic with the results of the strength test in the field of elastic-plastic deformations with the adopted ±15% error overlap on average by about 77%. The analyses were performed in the ABAQUS/Standard 2020 program in the field of elastic-plastic deformations. Research with the use of numerical models after extension with a damage model will enable the design of energy-saving and durable grinding machines.

Collapse of Tubes Under Combined Bending and Axial Compression Loads

2018 ◽  
Author(s):  
Shan Jin ◽  
Shuai Yuan ◽  
Yong Bai
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Axial Compression ◽  
Local Buckling ◽  
Practical Application ◽  
Buckling Modes ◽  
Combined Loads ◽  
Bending Loads ◽  
Good Agreement

In practical application, pipelines will inevitably experience bending and compression during manufacture, transportation and offshore installation. The mechanical behavior of tubes under combined axial compression and bending loads is investigated using experiments and finite element method in this paper. Tubes with D/t ratios in the range of 40 and 97 are adopted in the experiments. Then, the ultimate loads and the local buckling modes of tubes are studied. The commercial software ABAQUS is used to build FE models to simulate the load-shortening responses of tubes under combined loads. The results acquired from the ABAQUS simulation are compared with the ones from verification bending experiment, which are in good agreement with each other. The models in this paper are feasible to analyze the mechanical properties of tubes under combined axial compression and bending loads. The related results may be of interest to the manufacture engineers.

scholarly journals Effect of moisture content on the load carrying capacity and stiffness of corner wood-based and plastic joints

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 8640-8655
Author(s):  
Eliška Máchová ◽  
Nadežda Langová ◽  
Roman Réh ◽  
Pavol Joščák ◽  
Ľuboš Krišťák ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Moisture Content ◽  
Carrying Capacity ◽  
Calculated Data ◽  
Statistical Processing ◽  
Epoxy Adhesive ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Effect Of Moisture

The effect of moisture content on mechanical properties of corner furniture joints was evaluated for when different joining methods and materials were used. Results included statistical processing of the measured and calculated data and evaluation of the effect of selected factors on mechanical properties of joints caused by using mechanical fasteners and glue. The load-carrying capacity and stiffness of corner joints were investigated in two environments, humid and dry, with standard conditions for temperature and pressure, i.e., dry environment had a temperature of 23 °C ± 2 °C and relative humidity of 45% ± 5%, and the humid environment had a temperature of 23 °C ± 2 °C and relative humidity of 90% ± 5%. The two types of materials used were particleboard (PB) with a thickness of 12 mm and artificial stone (plastic) with a thickness of 12 mm. Both materials were tested individually as well as their combination. Epoxy and polyurethane (PUR) adhesives were used for the glued dowel joints. When the same materials were bonded, maximum load carrying capacity was achieved with PUR adhesive, material combination of plastic-plastic, and moisture content of 90%. The epoxy adhesive was most suitable for bonding materials with different properties.

Finite Element Modeling of Selective Laser Melting 316L Stainless Steel Parts for Evaluating the Mechanical Properties

2016 ◽  
Author(s):  
Arman Ahmadi ◽  
Narges Shayesteh Moghaddam ◽  
Mohammad Elahinia ◽  
Haluk E. Karaca ◽  
Reza Mirzaeifar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Model ◽  
Grain Boundaries ◽  
Mechanical Response ◽  
Element Model ◽  
Polycrystalline Materials ◽  
Microstructural Properties ◽  
Laser Melting

Selective laser melting (SLM) is an additive manufacturing technique in which complex parts can be fabricated directly by melting layers of powder from a CAD model. SLM has a wide range of application in biomedicine and other engineering areas and it has a series of advantages over traditional processing techniques. A large number of variables including laser power, scanning speed, scanning line spacing, layer thickness, material based input parameters, etc. have a considerable effect on SLM process materials. The interaction between these parameters is not completely studied. Limited studies on balling effect in SLM, densifications under different processing conditions, and laser re-melting, have been conducted that involved microstructural investigation. Grain boundaries are amongst the most important microstructural properties in polycrystalline materials with a significant effect on the fracture and plastic deformation. In SLM samples, in addition to the grain boundaries, the microstructure has another set of connecting surfaces between the melt pools. In this study, a computational framework is developed to model the mechanical response of SLM processed materials by considering both the grain boundaries and melt pool boundaries in the material. To this end, a 3D finite element model is developed to investigate the effect of various microstructural properties including the grains size, melt pools size, and pool connectivity on the macroscopic mechanical response of the SLM manufactured materials. A conventional microstructural model for studying polycrystalline materials is modified to incorporate the effect of connecting melt pools beside the grain boundaries. In this model, individual melt pools are approximated as overlapped cylinders each containing several grains and grain boundaries, which are modeled to be attached together by the cohesive zone method. This method has been used in modeling adhesives, bonded interfaces, gaskets, and rock fracture. A traction-separation description of the interface is used as the constitutive response of this model. Anisotropic elasticity and crystal plasticity are used as constitutive laws for the material inside the grains. For the experimental verification, stainless steel 316L flat dog bone samples are fabricated by SLM and tested in tension. During fabrication, the power of laser is constant, and the scan speed is changed to study the effect of fabrication parameters on the mechanical properties of the parts and to compare the result with the finite element model.

The Finite Element Analysis of Omni-Direction Side-Loading Forklift Truck Lifting System Based on COSMOSWorks

2012 ◽  
Vol 184-185 ◽  
pp. 534-537
Author(s):  
Jing Jing Zhou ◽  
Ai Dong Guo ◽  
Chun Hui Li ◽  
Zhen Jiang Lin ◽  
Tie Zhuang Wu
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Optimization ◽  
Experimental Measurements ◽  
Element Analysis ◽  
Forklift Truck ◽  
The Finite Element Analysis ◽  
Lifting System

By setting contact sets, achieved overall analysis results of the mechanical properties with omni-direction side-loading forklift truck lifting system based on COSMOSWorks. And made an experimental measurements to omni-direction side-loading forklift truck lifting system by electrometric methods. There was a good relevance between experimental data and calculation values, and the deviation was basically within the 10 percent allowed. Finally, in this way it verified the correctness and reliability of the finite element analysis by experimental measurements. Ensured the omni-direction side-loading forklift truck lifting system could be safe and efficient to work. And also it laid a foundation for subsequent structural optimization.

The Relationship Between Microstructure and Mechanical Properties of Late 19th/Early 20th Century Wrought Iron Using the Generalized Method of Cells Model

2002 ◽  
Vol 712 ◽  
Author(s):  
Jennifer J. Hooper ◽  
Lori Graham ◽  
Tim Foecke ◽  
Timothy P. Weihs
Keyword(s):  
Mechanical Properties ◽  
20Th Century ◽  
Mechanical Response ◽  
Early 20Th Century ◽  
Inelastic Behavior ◽  
Silicate Slag ◽  
Wrought Iron ◽  
Generalized Method Of Cells ◽  
The Relationship

ABSTRACTThe discovery of the RMS Titanic has led to a number of scientific studies, one of which addresses the role that the structural materials played in the sinking of the ship. Chemical, microstructural, and mechanical analysis of the hull steel suggests that it was state-of-the-art for 1912 with adequate fracture toughness for the application. However, the quality of the wrought iron rivets may have been an important factor in the opening of the steel plates during flooding. Preliminary studies of Titanic wrought iron rivets revealed an orthotropic, inhomogeneous composite material composed of glassy iron silicate (slag) particles embedded in a ferrite matrix. To date, very little is understood about the properties of wrought iron from that period. Therefore, in order to assess the quality of the Titanic material, contemporary wrought iron was obtained from additional late 19th/early 20th century buildings, bridges, and ships for comparison. Image analysis completed on the Titanic wrought iron microstructure showed a high slag content that is very coarse and unevenly distributed. To investigate how microstructure impacts the mechanical properties, and hence the quality of late 19th/early 20th century wrought iron, a detailed analysis of the relationship between the microstructural features and the mechanical behavior was completed. Here we present the first step in that process: the use of the Generalized Method of Cells (GMC) to predict the mechanical response of composites with variable microstructural properties. The GMC tool is used to generate the effective inelastic behavior of the composite from the individual constituent properties.

Numerical Simulation of Synthetic Microstructured Fibrillar Adhesive Pads

2009 ◽  
Author(s):  
Masoud Safdari ◽  
Majid Baniassadi ◽  
Akbar Ghazavizadeh ◽  
David Ruch ◽  
Said Ahzi
Keyword(s):  
Mechanical Properties ◽  
Experimental Measurements ◽  
Study Analysis ◽  
Uneven Surface ◽  
Biologically Inspired ◽  
Monte Carlo Techniques ◽  
Synthetic Adhesives ◽  
Adhesive Pads ◽  
Adhesion Performance ◽  
Good Agreement

Recently, the study, analysis and prototyping of biologically inspired adhesives pads have been subject of growing interest. These synthetic adhesives consist of rafts of tiny protruding fibers. The adhesion performance of these micro-engineered products is highly dependent on the geometrical and mechanical properties of microfibers and the surface they adhering to. Small fluctuations in these parameters can drastically change their adhesion performance. In this investigation, a more comprehensive mathematical model of a single micro-fiber with adhesion capability in contact with an uneven surface has been developed. To simulate realistic conditions, this analytical model could be extended to an array of micro-fibers. Using Monte Carlo techniques it was possible to study the behavior of an array of these micro-fibers under several degrees of uncertainty. The results deduced by this novel modeling approach are in good agreement with experimental measurements of adhesion performance in synthetic adhesive pads available in literature.

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