scholarly journals Nonlinear-Elastic Orthotropic Material Modeling of an Epoxy-Based Polymer for Predicting the Material Behavior of Transversely Loaded Fiber-Reinforced Composites

2020 ◽  
Vol 4 (2) ◽  
pp. 46
Author(s):  
Caroline Lüders
Keyword(s):  
Elastic Material ◽  
Orthotropic Material ◽  
Material Model ◽  
Material Behavior ◽  
Fiber Reinforced Composites ◽  
Material Modeling ◽  
Reinforced Composites ◽  
The Matrix ◽  
Nonlinear Elastic ◽  
Loaded Fiber

Micromechanical analyses of transversely loaded fiber-reinforced composites are conducted to gain a better understanding of the damage behavior and to predict the composite behavior from known parameters of the fibers and the matrix. Currently, purely elastic material models for the epoxy-based polymeric matrix do not capture the nonlinearity and the tension/compression-asymmetry of the resin’s material behavior. In the present contribution, a purely elastic material model is presented that captures these effects. To this end, a nonlinear-elastic orthotropic material modeling is proposed. Using this matrix material model, finite element-based simulations are performed to predict the composite behavior under transverse tension, transverse compression and shear. Therefore, the composite’s cross-section is modeled by a representative volume element. To evaluate the matrix modeling approach, the simulation results are compared to experimental data and the prediction error is computed. Furthermore, the accuracy of the prediction is compared to that of selected literature models. Compared to both experimental and literature data, the proposed modeling approach gives a good prediction of the composite behavior under matrix-dominated load cases.

scholarly journals Adaptive, Small-Rotation-Based, Corotational Technique for Analysis of 2D Nonlinear Elastic Frames

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Jaroon Rungamornrat ◽  
Saethapoom Sihanartkatakul ◽  
Pattawee Kanchanakitcharoen
Keyword(s):  
Elastic Material ◽  
Numerical Technique ◽  
Body Movement ◽  
Material Model ◽  
Material Behavior ◽  
Algebraic Equations ◽  
Nonlinear Elastic Material ◽  
Computational Performance ◽  
Nonlinear Elastic ◽  
Small Rotation

This paper presents an efficient and accurate numerical technique for analysis of two-dimensional frames accounted for both geometric nonlinearity and nonlinear elastic material behavior. An adaptive remeshing scheme is utilized to optimally discretize a structure into a set of elements where the total displacement can be decomposed into the rigid body movement and one possessing small rotations. This, therefore, allows the force-deformation relationship for the latter part to be established based on small-rotation-based kinematics. Nonlinear elastic material model is integrated into such relation via the prescribed nonlinear moment-curvature relationship. The global force-displacement relation for each element can be derived subsequently using corotational formulations. A final system of nonlinear algebraic equations along with its associated gradient matrix for the whole structure is obtained by a standard assembly procedure and then solved numerically by Newton-Raphson algorithm. A selected set of results is then reported to demonstrate and discuss the computational performance including the accuracy and convergence of the proposed technique.

Investigation of Fiber-Reinforced Modified Epoxy Resin Composites

2012 ◽  
Vol 510-511 ◽  
pp. 577-584 ◽  
Author(s):  
A. Quddos ◽  
Mohammad Bilal Khan ◽  
R.N. Khan ◽  
M.K.K. Ghauri
Keyword(s):  
Epoxy Resin ◽  
High Strength ◽  
Polymeric Matrix ◽  
Fiber Reinforced Composites ◽  
Resin Matrix ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Epoxy Resin Matrix ◽  
The Matrix ◽  
Modified Epoxy

The impregnation of the fiber with a resin system, the polymeric matrix with the interface needs to be properly cured so that the dimensional stability of the matrix and the composite is ensured. A modified epoxy resin matrix was obtained with a reactive toughening agent and anhydride as a curing agent. The mechanical properties of the modified epoxy matrix and its fiber reinforced composites were investigated systematically. The polymeric matrix possessed many good properties, including high strength, high elongation at break, low viscosity, long pot life at room temperature, and good water resistance. The special attentions are given to the matrix due to its low out gassing, low water absorption and radiation resistance. In addition, the fiber-reinforced composites showed a high strength conversion ratio of the fiber and good fatigue resistance. The dynamic and static of the composite material were studied by thermo gravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) with EDX. The influences of processing technique such as curing and proper mixing on the mechanical and interfacial properties were determined. The results demonstrated that the modified epoxy resin matrix is very suitable for applications in products fabricated with fiber-reinforced composites.

Machining parametric study on the natural fiber reinforced composites: A review

2021 ◽  
pp. 095440622110637
Author(s):  
Vijay Kumar Mahakur ◽  
Sumit Bhowmik ◽  
Promod Kumar Patowari
Keyword(s):  
Natural Fiber ◽  
Low Cost ◽  
Natural Fibers ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Machining Processes ◽  
Industrial Sectors ◽  
The Matrix ◽  
Input Variables

Nowadays, the utilization of natural fiber reinforced composite has increased frequently. These natural fibers have significant features like low cost, renewable, and, more importantly, biodegradable in nature, making them to be utilized for various industrial sectors. However, the massive demand for natural fiber reinforced composites (NFRC), forces them to be machined and operated, which is required for countless areas in multiple industries like automotive, marine, aerospace and constructions. But before obtaining the final shape of any specimen, this specimen should come across numerous machining processes to get the desired shape and structure. Therefore, the present review paper focused on the various aspects during conventional and unconventional machining of the NFRC. It covers the work by exploring the influence of all input variables on the outcome produced after machining the NFRC. Various methodologies and tools are also discussed in this article for reducing the machining defects. The machining of the NFRC is found as a challenging task due to insufficient interlocking between the matrix and fibers, and minimum knowledge in machining characteristics and appropriate input parameters. Thus, this review is trying to assist the readers to grasp a basic understanding and information during the machining of the NFRC in every aspect.

Shear Load Transfer in Shape Memory Alloy Fiber Reinforced Composites During Elastic Axisymmetric Deformations

2000 ◽  
Author(s):  
Hungyu Tsai ◽  
Xinjian Fan
Keyword(s):  
Phase Transformation ◽  
Stress Concentration ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Transition Layer ◽  
Load Transfer ◽  
Fiber Reinforced Composites ◽  
Shear Load ◽  
Reinforced Composites ◽  
The Matrix

Abstract The axisymmetric elastic deformations in shape memory alloy (SMA) fiber reinforced composites are studied. We analyze the stress concentration near the interface between the fiber and the matrix as a result of a pre-described phase transformation in the active fiber. A typical model involving a single infinite fiber embedded in an infinite elastic matrix is studied. A portion of the fiber is allowed to undergo phase transformation along the axial direction so that its length is changed by the corresponding transformation strain (typically a few percentages), while the matrix is assumed to be linearly elastic and isotropic. Under certain bonding conditions, the deformation of fiber forces the matrix to deform in the elastic regime in order to accommodate the transformation strains. The problem is formulated as axisymmetric deformations coupled with a finite transformation region in the fiber. In order to avoid infinite stresses found under perfect bonding conditions, we adopt a “spring” model which accounts for the elasticity of a transition layer at the interface. This model allows for relative displacements between the fiber and the matrix. A linear relation between this relative displacement and the shear stress is used. The exact elasticity solution (in integral form) to this problem is found using Love’s stress function and Fourier transform. Numerical integration is performed to produce the stress distributions. In particular, the shear load transfer profiles along the interface are calculated for various spring stiffness. It is found that the singularity is eliminated and the stress concentration factor depends on the stiffness of the transition layer.

scholarly journals Efficient Hydrophobic Modification of Old Newspaper and Its Application in Paper Fiber Reinforced Composites

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 842 ◽  
Author(s):  
Weiwei Zhang ◽  
Jin Gu ◽  
Dengyun Tu ◽  
Litao Guan ◽  
Chuanshuang Hu
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Natural Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Oh Groups ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Paper Fibers

Paper fibers have gained broad attention in natural fiber reinforced composites in recent years. The specific problem in preparing paper fiber reinforced composites is that paper fibers easily become flocculent after pulverization, which increases difficulties during melt-compounding with polymer matrix and results in non-uniform dispersion of paper fibers in the matrix. In this study, old newspaper (ONP) was treated with a low dosage of gaseous methyltrichlorosilane (MTCS) to solve the flocculation. The modified ONP fibers were characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TG). Then the modified ONP fibers and high-density polyethylene (HDPE) were extruded and pelletized to prepare ONP/HDPE composites via injection molding. Maleic anhydride-grafted polyethylene (MAPE) was added to enhance the interfacial bonding performance with the ultimate purpose of improving the mechanical strength of the composites. The mechanical properties such as tensile, flexural, and impact strength and the water absorption properties of the composite were tested. The results showed that the formation of hydrogen bonding between ONP fibers was effectively prevented after MTCS treatment due to the reduction of exposed –OH groups at the fiber surface. Excessive dosage of MTCS led to severe fiber degradation and dramatically reduced the aspect ratio of ONP fibers. Composites prepared with ONP fibers modified with 4% (v/w) MTCS showed the best mechanical properties due to reduced polarity between the fibers and the matrix, and the relatively long aspect ratio of treated ONP fibers. The composite with or without MAPE showed satisfactory water resistance properties. MTCS was proven to be a cheap and efficient way to pretreat old newspaper for preparing paper fiber reinforced composites.

Micromechanics-based analyses of short fiber-reinforced composites with functionally graded interphases

2019 ◽  
Vol 54 (8) ◽  
pp. 1031-1048 ◽  
Author(s):  
Yang Yang ◽  
Qi He ◽  
Hong-Liang Dai ◽  
Jian Pang ◽  
Liang Yang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Elastic Properties ◽  
Effective Properties ◽  
Micromechanical Model ◽  
Short Fiber ◽  
Functionally Graded ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
The Matrix

A micromechanical model for short fiber-reinforced composites (SFRCs) with functionally graded interphases and a systematic prediction scheme to determine the effective properties are presented. The matrix and the fibers are regarded to be linear elastic, isotropic, and homogeneous. Fibers are assumed to be ellipsoids coated perfectly by functionally graded interphases, which is supposed to be formed chemically or physically by the constituents near the interface. First, to analyze the grading interphase effect, layer-wise concept is followed to divide the functionally graded interphases into multi-homogeneous sub-layers. Next, to take the effect of functionally graded interphases into account, a combination of multi-inclusion method and Mori–Tanaka method is applied to predict effective elastic properties of this unidirectional SFRCs with respect to the content and aspect ratio of the inclusions. By employing coordinate transformation, spatially elastic moduli are obtained. Finally, Voigt homogenization scheme is used to obtain the overall, averaged, symmetrical elastic properties of the SFRCs. Numerical examples and analyses demonstrate the applicability of the proposed method and indicate the influences of graded interphase, orientation, and aspect ratio of inclusions as well as properties and contents of the constituents on the overall properties of SFRCs.

A New Embedded-Zone Method on Computation of the Transverse Elastic Properties of Fiber-Reinforced Composites

2005 ◽  
Author(s):  
Xiaochun Wang
Keyword(s):  
Plane Strain ◽  
Elastic Properties ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Zone Method ◽  
Two Dimension ◽  
The Matrix ◽  
Strain Model ◽  
Plane Strain Model

There are many methods on computation of transverse elastic properties of unidirectional fiber-reinforced composites when using the finite element method, such as three-dimension model, two-dimension plane strain model, unit cell model, etc[1]. But unit cell models could be used only when the fibers are arrayed regularly. The computations of three- and two-dimension plane strain models are tremendous when many fine fibers are spread randomly in the matrix so that the properties of block of composite must be computed. The paper proposes a new embedded-zone method to compute the transverse elastic properties for a block of fiber-reinforced composites containing a great amount of fibers embedded in the matrix stochastically while using very little computational work compared with three- and two-dimension plane strain model. The transverse elastic modulus and shear modulus of unidirectional fiber-reinforced composites are computed.

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