Flexural Behavior of a Layer-to-Layer Orthogonal Interlocked Three-Dimensional Textile Composite

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
D. Zhang ◽  
A. M. Waas ◽  
M. Pankow ◽  
C. F. Yen ◽  
S. Ghiorse
Keyword(s):  
Mechanical Response ◽  
Peak Load ◽  
Three Dimensional ◽  
Peak Stress ◽  
Surface Strain ◽  
Image Correlation ◽  
Flexural Behavior ◽  
Fe Model ◽  
Textile Composite ◽  
The Matrix

The flexural response of a three-dimensional (3D) layer-to-layer orthogonal interlocked textile composite has been investigated under quasi-static three-point bending. Fiber tow kinking on the compressive side of the flexed specimens has been found to be a strength limiting mechanism for both warp and weft panels. The digital image correlation (DIC) technique has been utilized to map the deformation and identify the matrix microcracking on the tensile side prior to the peak load in the warp direction loaded panels. It has been shown that the geometrical characteristics of textile reinforcement play a key role in the mechanical response of this class of material. A 3D local–global finite element (FE) model that reflects the textile architectures has been proposed to successfully capture the surface strain localizations in the predamage region. To analyze the kink banding event, the fiber tow is modeled as an inelastic degrading homogenized orthotropic solid in a state of plane stress based on Schapery Theory (ST). The predicted peak stress is in agreement with the tow kinking stress obtained from the 3D FE model.

Experimental Characterization and Finite Element Modeling of Film Capacitors for Automotive Applications

2016 ◽  
Author(s):  
D. Croccolo ◽  
T. M. Brugo ◽  
M. De Agostinis ◽  
S. Fini ◽  
G. Olmi
Keyword(s):  
Finite Element ◽  
Mechanical Response ◽  
High Reliability ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Life Time ◽  
Element Model ◽  
Image Correlation ◽  
Thermal Loads ◽  
Mechanical Shock

As electronics keeps on its trend towards miniaturization, increased functionality and connectivity, the need for improved reliability capacitors is growing rapidly in several industrial compartments, such as automotive, medical, aerospace and military. Particularly, recent developments of the automotive compartment, mostly due to changes in standards and regulations, are challenging the capabilities of capacitors in general, and especially film capacitors. Among the required features for a modern capacitor are the following: (i) high reliability under mechanical shock, (ii) wide working temperature range, (iii) high insulation resistance, (iv) small dimensions, (v) long expected life time and (vi) high peak withstanding voltage. This work aims at analyzing the key features that characterize the mechanical response of the capacitor towards temperature changes. Firstly, all the key components of the capacitor have been characterized, in terms of strength and stiffness, as a function of temperature. These objectives have been accomplished by means of several strain analysis methods, such as strain gauges, digital image correlation (DIC) or dynamic mechanical analysis (DMA). All the materials used to manufacture the capacitor, have been characterized, at least, with respect to their Young’s modulus and Poisson’s ratio. Then, a three-dimensional finite element model of the whole capacitor has been set up using the ANSYS code. Based on all the previously collected rehological data, the numerical model allowed to simulate the response in terms of stress and strain of each of the capacitor components when a steady state thermal load is applied. Due to noticeable differences between the thermal expansion coefficients of the capacitor components, stresses and strains build up, especially at the interface between different components, when thermal loads are applied to the assembly. Therefore, the final aim of these numerical analyses is to allow the design engineer to define structural optimization strategies, aimed at reducing the mechanical stresses on the capacitor components when thermal loads are applied.

The Effect of Trabecular Bone on the Mechanical Response of Human Mandible with Implant

2014 ◽  
Vol 695 ◽  
pp. 588-591
Author(s):  
Khairul Salleh Basaruddin ◽  
Ruslizam Daud
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Trabecular Bone ◽  
Static Analysis ◽  
Load Distribution ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Fe Model ◽  
Micro Computed Tomography ◽  
Bone Specimen

This study aims to investigate the influence of trabecular bone in human mandible bone on the mechanical response under implant load. Three dimensional voxel finite element (FE) model of mandible bone was reconstructed from micro-computed tomography (CT) images that were captured from bone specimen. Two FE models were developed where the first consists of cortical bone, trabecular bone and implants, and trabecular bone part was excluded in the second model. A static analysis was conducted on both models using commercial software Voxelcon. The results suggest that trabecular bone contributed to the strength of human mandible bone and to the effectiveness of load distribution under implant load.

A finite element model to study the effect of porosity location on the elastic modulus of a cantilever beam

2019 ◽  
Vol 43 (4) ◽  
pp. 443-453
Author(s):  
Stephen M. Handrigan ◽  
Sam Nakhla
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Fe Model ◽  
Three Dimensional Finite Element

An investigation to determine the effect of porosity concentration and location on elastic modulus is performed. Due to advancements in testing methods, the manufacturing and testing of microbeams to obtain mechanical response is possible through the use of focused ion beam technology. Meanwhile, rigorous analysis is required to enable accurate extraction of the elastic modulus from test data. First, a one-dimensional investigation with beam theory, Euler–Bernoulli and Timoshenko, was performed to estimate the modulus based on load-deflection curve. Second, a three-dimensional finite element (FE) model in Abaqus was developed to identify the effect of porosity concentration. Furthermore, the current work provided an accurate procedure to enable accurate extraction of the elastic modulus from load-deflection data. The use of macromodels such as beam theory and three-dimensional FE model enabled enhanced understanding of the effect of porosity on modulus.

scholarly journals The effect of processing parameters on the mechanical characteristics of PLA produced by a 3D FFF printer

2020 ◽  
Vol 111 (3-4) ◽  
pp. 695-709
Author(s):  
H. Gonabadi ◽  
A. Yadav ◽  
S. J. Bull
Keyword(s):  
Tensile Strength ◽  
Young’S Modulus ◽  
Process Parameters ◽  
Mechanical Response ◽  
Complex Geometry ◽  
Young's Modulus ◽  
Laminate Plate ◽  
Surface Strain ◽  
Image Correlation ◽  
Build Orientation

Abstract 3D printing by fused filament fabrication (FFF) provides an innovative manufacturing method for complex geometry components. Since FFF is a layered manufacturing process, effects of process parameters are of concern when plastic materials such as polylactic acid (PLA), polystyrene and nylon are used. This study explores how the process parameters, e.g. build orientation and infill pattern/density, affect the mechanical response of PLA samples produced using FFF. Digital image correlation (DIC) was employed to get full-field surface-strain measurements. The results show the influence of build orientation and infill density is significant. For on-edge orientation, the tensile strength and Young’s modulus were 55 MPa and 3.5 GPa respectively, which were about 91% and 40% less for the upright orientation, demonstrating a significant anisotropy. The tensile strength and Young’s modulus increased with increasing infill density. In contrast, different infill patterns have no significant effect. Considering the influence of build orientation, based on the experimental results, a constitutive model derived from the laminate plate theory was employed. The material parameters were determined by tensile tests. Results demonstrated a reasonable agreement between the experimental data and the predictive model. Similar anisotropy to tension was observed in shear tests; shear modulus and shear strength for 45° flat orientation were about 1.55 GPa and 36 MPa, whereas for upright specimens they were about 0.95 GPa and 18 MPa, respectively. The findings provide a framework for systematic mechanical characterisation of 3D-printed polymers and potential ways of choosing process parameters to maximise performance for a given design.

scholarly journals Prediction of Bending, Buckling and Free-Vibration Behaviors of 3D Textile Composite Plates by Using VAM-Based Equivalent Model

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 134
Author(s):  
Senbiao Xi ◽  
Yifeng Zhong ◽  
Zheng Shi ◽  
Qingshan Yi
Keyword(s):  
Free Vibration ◽  
Composite Plate ◽  
Three Dimensional ◽  
Composite Plates ◽  
Unit Cell ◽  
Equivalent Model ◽  
Fe Model ◽  
Equivalent Stiffness ◽  
Textile Composite ◽  
3D Fem

To solve the microstructure-related complexity of a three-dimensional textile composite, a novel equivalent model was established based on the variational asymptotic method. The constitutive modeling of 3D unit cell within the plate was performed to obtain the equivalent stiffness, which can be inputted into the 2D equivalent model (2D-EPM) to perform the bending, free-vibration and buckling analysis. The correctness and effectiveness of the 2D-EPM was validated by comparing with the results from 3D FE model (3D-FEM) under various conditions. The influence of yarn width and spacing on the equivalent stiffness was also discussed. Finally, the effective performances of 3D textile composite plate and 2D plain-woven laminate with the same thickness and yarn content were compared. The results revealed that the bending, buckling and free-vibration behaviors predicted by 2D-EPM were in good agreement with 3D-FEM, and the local field distributions within the unit cell of 3D textile composite plate were well captured. Compared with the 2D plain-woven laminate, the displacement of 3D textile composite plate was relatively larger under the uniform load, which may due to the fact that the through-the-thickness constrains of the former are only dependent on the binder yarns, while the warp yarns and weft yarns of the latter are intertwined closely.

scholarly journals An Efficient Approach to Describe the Fiber Effect on Mechanical Performance of Pultruded GFRP Profiles

2021 ◽  
Vol 8 ◽  
Author(s):  
Viktor Gribniak ◽  
Arvydas Rimkus ◽  
Linas Plioplys ◽  
Ieva Misiūnaitė ◽  
Mantas Garnevičius ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Mechanical Load ◽  
Computation Time ◽  
Image Correlation ◽  
Flexural Behavior ◽  
Bending Test ◽  
Experimental Program ◽  
Fe Model ◽  
Hollow Section ◽  
Structural Applications

This study focuses on the flexural behavior of pultruded glass fiber-reinforced polymer (GFRP) profiles developed for structural applications. Fiber content is a commonly accepted measure for estimating the resistance of such components, and technical datasheets describe this essential parameter. However, its direct implementation to the numerical simulations can face substantial problems because of the limitations of standard test protocols. Furthermore, the fiber mass percentage understandable for producers is unsuitable for typical software considered the volumetric reinforcement content. This manuscript exemplifies the above situation both experimentally and analytically, investigating two GFRP square hollow section (SHS) profiles available at the market. A three-point bending test determines the mechanical performance of the profiles in this experimental program; a digital image correlation system captures deformations and failure mechanisms of the SHS specimens; a standard tensile test defines the material properties. A simplified finite element (FE) model is developed based on the smeared reinforcement concept to predict the stiffness and load-bearing capacity of the profiles. An efficient balance between the prediction accuracy and computation time characterizes the developed FE approach that does not require specific descriptions of reinforcement geometry and refined meshes necessary for modeling the discrete fibers. The proposed FE approach is also used to analyze the fiber efficiency in reinforcing the polymer matrix. The efficiency is understood as the model’s ability to resist mechanical load proportional to the dry filaments’ content and experimental elastic modulus value. Scanning electron microscopy relates the composite microstructure and the mechanical performance of the selected profiles in this study.

scholarly journals Bio-Inspired 3D Infill Patterns for Additive Manufacturing and Structural Applications

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 499 ◽  
Author(s):  
Jan Podroužek ◽  
Marco Marcon ◽  
Krešimir Ninčević ◽  
Roman Wan-Wendner
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Peak Load ◽  
Fem Analysis ◽  
Material Model ◽  
Surface Strain ◽  
Image Correlation ◽  
Nonlinear Material ◽  
Full Field ◽  
Structural Applications

The aim of this paper is to introduce and characterize, both experimentally and numerically, three classes of non-traditional 3D infill patterns at three scales as an alternative to classical 2D infill patterns in the context of additive manufacturing and structural applications. The investigated 3D infill patterns are biologically inspired and include Gyroid, Schwarz D and Schwarz P. Their selection was based on their beneficial mechanical properties, such as double curvature. They are not only known from nature but also emerge from numerical topology optimization. A classical 2D hexagonal pattern has been used as a reference. The mechanical performance of 14 cylindrical specimens in compression is quantitatively related to stiffness, peak load and weight. Digital image correlation provides accurate full-field deformation measurements and insights into periodic features of the surface strain field. The associated variability, which is inherent to the production and testing process, has been evaluated for 3 identical Gyroid specimens. The nonlinear material model for the preliminary FEM analysis is based on tensile test specimens with 3 different slicing strategies. The 3D infill patterns are generally useful when the extrusion orientation cannot be aligned with the build orientation and the principal stress field, i.e., in case of generative design, such as the presented branching structure, or any complex shape and boundary condition.

A Three-Dimensional Human Trunk Model for the Analysis of Respiratory Mechanics

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Michel Behr ◽  
Jeremie Pérès ◽  
Maxime Llari ◽  
Yves Godio ◽  
Yves Jammes ◽  
...  
Keyword(s):  
Road Safety ◽  
Mechanical Response ◽  
Respiratory Mechanics ◽  
Numerical Models ◽  
Three Dimensional ◽  
Abdominal Pressure ◽  
Fe Model ◽  
Safety Research ◽  
Impact Biomechanics ◽  
Validation Parameters

Over the past decade, road safety research and impact biomechanics have strongly stimulated the development of anatomical human numerical models using the finite element (FE) approach. The good accuracy of these models, in terms of geometric definition and mechanical response, should now find new areas of application. We focus here on the use of such a model to investigate its potential when studying respiratory mechanics. The human body FE model used in this study was derived from the RADIOSS® HUMOS model. Modifications first concerned the integration and interfacing of a user-controlled respiratory muscular system including intercostal muscles, scalene muscles, the sternocleidomastoid muscle, and the diaphragm and abdominal wall muscles. Volumetric and pressure measurement procedures for the lungs and both the thoracic and abdominal chambers were also implemented. Validation of the respiratory module was assessed by comparing a simulated maximum inspiration maneuver to volunteer studies in the literature. Validation parameters included lung volume changes, rib rotations, diaphragm shape and vertical deflexion, and intra-abdominal pressure variation. The HUMOS model, initially dedicated to road safety research, could be turned into a promising, realistic 3D model of respiration with only minor modifications.

An Experimental and Numerical Study on the Axial Compression Response of Flexible Pipes

2010 ◽  
Author(s):  
Jose´ Renato M. de Sousa ◽  
Paula F. Viero ◽  
Carlos Magluta ◽  
Ney Roitman
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Mechanical Response ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Mechanical Analysis ◽  
Fe Model ◽  
Flexible Pipe ◽  
Flexible Pipes

This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover, in order to validate this model, experimental tests carried out at COPPE/UFRJ are also described. In these tests, a typical 4″ flexible pipe was subjected to axial compression until its failure is reached. Radial and axial displacements were measured and compared to the model predictions. The good agreement between all obtained results points that the proposed FE model is efficient to estimate the response of flexible pipes to axial compression and, furthermore, has potential to be employed in the identification of the failure modes related to excessive axial compression as well as in the mechanical analysis of flexible pipes under other types of loads.

scholarly journals A method for predicting the blasting pressure of balloons using the surface strain in low pressure

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988155
Author(s):  
Yong-Zheng Shen ◽  
Guo-Chang Lin ◽  
Hui-Feng Tan
Keyword(s):  
Internal Pressure ◽  
Correction Factor ◽  
Three Dimensional ◽  
Reference Value ◽  
Surface Strain ◽  
Test Strain ◽  
Image Correlation ◽  
Correlation Technique ◽  
Maximum Test ◽  
Novel Method

Balloons made by cut fabric pieces are widely used in space research. To predict the blasting pressure of a balloon, we propose a novel method based on the non-contact test strain at a low internal pressure. The three-dimensional digital image correlation technique is introduced to measure the surface strain of the balloon. Representative regions of the balloon are selected as the test regions. A correction factor is proposed that accounts for the relationship between the internal pressure and the surface strain for the actual and the ideal balloon. By combining the maximum surface strain at a given internal pressure and the correction factor, we can predict the blasting pressure of the balloon. A blasting test is carried out to verify the feasibility of the predictive method. When the value of the ratio of the maximum test strain to the limiting strain reaches about a reference value, the absolute value of the deviation percentage between the predicted blasting pressure and the actual blasting pressure is less than 10%. The blasting pressure for balloon can be predicted accurately. This method does not require the balloon to be inflated to a high internal pressure, which improves the practicality of the prediction.

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