Materials

Research

13 pages, 1616 KiB

Open AccessFeature PaperArticle

Production of Low Cost Carbon-Fiber through Energy Optimization of Stabilization Process

by Gelayol Golkarnarenji, Minoo Naebe, Khashayar Badii, Abbas S. Milani, Reza N. Jazar and Hamid Khayyam

Materials 2018, 11(3), 385; https://doi.org/10.3390/ma11030385 - 05 Mar 2018

Cited by 26 | Viewed by 4772

Abstract

To produce high quality and low cost carbon fiber-based composites, the optimization of the production process of carbon fiber and its properties is one of the main keys. The stabilization process is the most important step in carbon fiber production that consumes a [...] Read more.

To produce high quality and low cost carbon fiber-based composites, the optimization of the production process of carbon fiber and its properties is one of the main keys. The stabilization process is the most important step in carbon fiber production that consumes a large amount of energy and its optimization can reduce the cost to a large extent. In this study, two intelligent optimization techniques, namely Support Vector Regression (SVR) and Artificial Neural Network (ANN), were studied and compared, with a limited dataset obtained to predict physical property (density) of oxidative stabilized PAN fiber (OPF) in the second zone of a stabilization oven within a carbon fiber production line. The results were then used to optimize the energy consumption in the process. The case study can be beneficial to chemical industries involving carbon fiber manufacturing, for assessing and optimizing different stabilization process conditions at large. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

12 pages, 3605 KiB

Open AccessArticle

Computational and Experimental Mechanical Modelling of a Composite Grouted Splice Sleeve Connector System

by Zhiping Kuang and Guanyu Zheng

Materials 2018, 11(2), 306; https://doi.org/10.3390/ma11020306 - 20 Feb 2018

Cited by 29 | Viewed by 5396

Abstract

Owing to its controllable tolerance, simple operation and no need for welding at construction site, the composite system involving grouted cement material, steel material and ductile iron material is widely used as grouted splice sleeve (GSS) connector for connecting precast concrete structures. However, [...] Read more.

Owing to its controllable tolerance, simple operation and no need for welding at construction site, the composite system involving grouted cement material, steel material and ductile iron material is widely used as grouted splice sleeve (GSS) connector for connecting precast concrete structures. However, the current design recommendations for such a composite connection system do not accurately account for its material nonlinearity behavior. In the present study, a three-dimensional nonlinear finite element model of a GSS connector is developed by considering the nonlinear material behavior of each component to fully investigate its mechanical performance under axial tension. To validate the proposed computational model and demonstrate the nonlinear response of the GSS connector, the pullout experimental test of two engineering specimens is carried out under monotonic tensile load, and a good agreement between the numerical and experimental test results is observed. Then, the sensitivity analysis of some controlling material properties and geometrical parameters is performed using the validated computational model to further understand the performance of such a composite structure in load carrying capacity and ductility of the connections to meet the rapid engineering applications of precast concrete structures. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

12 pages, 1973 KiB

Open AccessArticle

Thermoauxetic Behavior of Composite Structures

by Hubert Jopek and Tomasz Stręk

Materials 2018, 11(2), 294; https://doi.org/10.3390/ma11020294 - 13 Feb 2018

Cited by 41 | Viewed by 3878

Abstract

This paper presents a study of new two-dimensional composite structures with respect to their thermomechanical properties. The investigated structures are based on very well-known auxetic geometries—i.e., the anti-tetrachiral and re-entrant honeycomb—modified by additional linking elements, material which is highly sensitive to changes of [...] Read more.

This paper presents a study of new two-dimensional composite structures with respect to their thermomechanical properties. The investigated structures are based on very well-known auxetic geometries—i.e., the anti-tetrachiral and re-entrant honeycomb—modified by additional linking elements, material which is highly sensitive to changes of temperature. The study shows that temperature can be used as a control parameter to tune the value of the effective Poisson’s ratio, which allows, in turn, changing its value from positive to negative, according to the temperature applied. The study shows that such thermoauxetic behavior applies both to composites with voids and those completely filled with material. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Graphical abstract

6865 KiB

Open AccessFeature PaperArticle

Effect of Fungal Deterioration on Physical and Mechanical Properties of Hemp and Flax Natural Fiber Composites

by Bryn Crawford, Sepideh Pakpour, Negin Kazemian, John Klironomos, Karen Stoeffler, Denis Rho, Johanne Denault and Abbas S. Milani

Materials 2017, 10(11), 1252; https://doi.org/10.3390/ma10111252 - 31 Oct 2017

Cited by 27 | Viewed by 6498

Abstract

The development and application of bio-sourced composites have been gaining wide attention, yet their deterioration due to the growth of ubiquitous microorganisms during storage/manufacturing/in-service phases is still not fully understood for optimum material selection and design purposes. In this study, samples of non-woven [...] Read more.

The development and application of bio-sourced composites have been gaining wide attention, yet their deterioration due to the growth of ubiquitous microorganisms during storage/manufacturing/in-service phases is still not fully understood for optimum material selection and design purposes. In this study, samples of non-woven flax fibers, hemp fibers, and mats made of co-mingled randomly-oriented flax or hemp fiber (50%) and polypropylene fiber (50%) were subjected to 28 days of exposure to (i) no water-no fungi, (ii) water only and (iii) water along with the Chaetomium globosum fungus. Biocomposite samples were measured for weight loss over time, to observe the rate of fungal growth and the respiration of cellulose components in the fibers. Tensile testing was conducted to measure mechanical properties of the composite samples under different configurations. Scanning electron microscopy was employed to visualize fungal hyphal growth on the natural fibers, as well as to observe the fracture planes and failure modes of the biocomposite samples. Results showed that fungal growth significantly affects the dry mass as well as the tensile elastic modulus of the tested natural fiber mats and composites, and the effect depends on both the type and the length scale of fibers, as well as the exposure condition and time. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Graphical abstract

5853 KiB

Open AccessArticle

A Mesoscopic Analytical Model to Predict the Onset of Wrinkling in Plain Woven Preforms under Bias Extension Shear Deformation

by Abbas Hosseini, Masoud Haghi Kashani, Farrokh Sassani, Abbas S. Milani and Frank Ko

Materials 2017, 10(10), 1184; https://doi.org/10.3390/ma10101184 - 16 Oct 2017

Cited by 10 | Viewed by 4139

Abstract

A mesoscopic analytical model of wrinkling of Plain-Woven Composite Preforms (PWCPs) under the bias extension test is presented, based on a new instability analysis. The analysis is aimed to facilitate a better understanding of the nature of wrinkle formation in woven fabrics caused [...] Read more.

A mesoscopic analytical model of wrinkling of Plain-Woven Composite Preforms (PWCPs) under the bias extension test is presented, based on a new instability analysis. The analysis is aimed to facilitate a better understanding of the nature of wrinkle formation in woven fabrics caused by large in-plane shear, while it accounts for the effect of fabric and process parameters on the onset of wrinkling. To this end, the mechanism of wrinkle formation in PWCPs in mesoscale is simplified and an equivalent structure composed of bars and different types of springs is proposed, mimicking the behavior of a representative PWCP element at the post-locking state. The parameters of this equivalent structure are derived based on geometric and mechanical characteristics of the PWCP. The principle of minimum total potential energy is employed to formluate the model, and experimental validation is carried out to reveal the effectiveness of the derived wrinkling prediction equation. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

1014 KiB

Open AccessArticle

A Simulation of Low and High Cycle Fatigue Failure Effects for Metal Matrix Composites Based on Innovative J₂-Flow Elastoplasticity Model

by Zhaoling Wang and Heng Xiao

Materials 2017, 10(10), 1126; https://doi.org/10.3390/ma10101126 - 24 Sep 2017

Cited by 6 | Viewed by 4243

Abstract

New elastoplastic

J_{2}

-flow constitutive equations at finite deformations are proposed for the purpose of simulating the fatigue failure behavior for metal matrix composites. A new, direct approach is established in a two-fold sense of unification. Namely, both low and high cycle [...] Read more.

New elastoplastic

J_{2}

-flow constitutive equations at finite deformations are proposed for the purpose of simulating the fatigue failure behavior for metal matrix composites. A new, direct approach is established in a two-fold sense of unification. Namely, both low and high cycle fatigue failure effects of metal matrix composites may be simultaneously simulated for various cases of the weight percentage of reinforcing particles. Novel results are presented in four respects. First, both the yield condition and the loading–unloading conditions in a usual sense need not be involved but may be automatically incorporated into inherent features of the proposed constitutive equations; second, low-to-high cycle fatigue failure effects may be directly represented by a simple condition for asymptotic loss of the material strength, without involving any additional damage-like variables; third, both high and low cycle fatigue failure effects need not be separately treated but may be automatically derived as model predictions with a unified criterion for critical failure states, without assuming any ad hoc failure criteria; and, finally, explicit expressions for each incorporated model parameter changing with the weight percentage of reinforcing particles may be obtainable directly from appropriate test data. Numerical examples are presented for medium-to-high cycle fatigue failure effects and for complicated duplex effects from low to high cycle fatigue failure effects. Simulation results are in good agreement with experimental data. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

11559 KiB

Open AccessArticle

Multi-Scale Low-Entropy Method for Optimizing the Processing Parameters during Automated Fiber Placement

by Zhenyu Han, Shouzheng Sun, Hongya Fu and Yunzhong Fu

Materials 2017, 10(9), 1024; https://doi.org/10.3390/ma10091024 - 03 Sep 2017

Cited by 15 | Viewed by 5678

Abstract

Automated fiber placement (AFP) process includes a variety of energy forms and multi-scale effects. This contribution proposes a novel multi-scale low-entropy method aiming at optimizing processing parameters in an AFP process, where multi-scale effect, energy consumption, energy utilization efficiency and mechanical properties of [...] Read more.

Automated fiber placement (AFP) process includes a variety of energy forms and multi-scale effects. This contribution proposes a novel multi-scale low-entropy method aiming at optimizing processing parameters in an AFP process, where multi-scale effect, energy consumption, energy utilization efficiency and mechanical properties of micro-system could be taken into account synthetically. Taking a carbon fiber/epoxy prepreg as an example, mechanical properties of macro–meso–scale are obtained by Finite Element Method (FEM). A multi-scale energy transfer model is then established to input the macroscopic results into the microscopic system as its boundary condition, which can communicate with different scales. Furthermore, microscopic characteristics, mainly micro-scale adsorption energy, diffusion coefficient entropy–enthalpy values, are calculated under different processing parameters based on molecular dynamics method. Low-entropy region is then obtained in terms of the interrelation among entropy–enthalpy values, microscopic mechanical properties (interface adsorbability and matrix fluidity) and processing parameters to guarantee better fluidity, stronger adsorption, lower energy consumption and higher energy quality collaboratively. Finally, nine groups of experiments are carried out to verify the validity of the simulation results. The results show that the low-entropy optimization method can reduce void content effectively, and further improve the mechanical properties of laminates. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

9913 KiB

Open AccessArticle

Seismic and Restoration Assessment of Monumental Masonry Structures

by Panagiotis G. Asteris, Maria G. Douvika, Maria Apostolopoulou and Antonia Moropoulou

Materials 2017, 10(8), 895; https://doi.org/10.3390/ma10080895 - 02 Aug 2017

Cited by 19 | Viewed by 5412

Abstract

Masonry structures are complex systems that require detailed knowledge and information regarding their response under seismic excitations. Appropriate modelling of a masonry structure is a prerequisite for a reliable earthquake-resistant design and/or assessment. However, modelling a real structure with a robust quantitative (mathematical) [...] Read more.

Masonry structures are complex systems that require detailed knowledge and information regarding their response under seismic excitations. Appropriate modelling of a masonry structure is a prerequisite for a reliable earthquake-resistant design and/or assessment. However, modelling a real structure with a robust quantitative (mathematical) representation is a very difficult, complex and computationally-demanding task. The paper herein presents a new stochastic computational framework for earthquake-resistant design of masonry structural systems. The proposed framework is based on the probabilistic behavior of crucial parameters, such as material strength and seismic characteristics, and utilizes fragility analysis based on different failure criteria for the masonry material. The application of the proposed methodology is illustrated in the case of a historical and monumental masonry structure, namely the assessment of the seismic vulnerability of the Kaisariani Monastery, a byzantine church that was built in Athens, Greece, at the end of the 11th to the beginning of the 12th century. Useful conclusions are drawn regarding the effectiveness of the intervention techniques used for the reduction of the vulnerability of the case-study structure, by means of comparison of the results obtained. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

2061 KiB

Open AccessArticle

Experimental and Theoretical Modal Analysis of Full-Sized Wood Composite Panels Supported on Four Nodes

by Cheng Guan, Houjiang Zhang, Xiping Wang, Hu Miao, Lujing Zhou and Fenglu Liu

Materials 2017, 10(6), 683; https://doi.org/10.3390/ma10060683 - 21 Jun 2017

Cited by 22 | Viewed by 5323

Abstract

Key elastic properties of full-sized wood composite panels (WCPs) must be accurately determined not only for safety, but also serviceability demands. In this study, the modal parameters of full-sized WCPs supported on four nodes were analyzed for determining the modulus of elasticity ( [...] Read more.

Key elastic properties of full-sized wood composite panels (WCPs) must be accurately determined not only for safety, but also serviceability demands. In this study, the modal parameters of full-sized WCPs supported on four nodes were analyzed for determining the modulus of elasticity (E) in both major and minor axes, as well as the in-plane shear modulus of panels by using a vibration testing method. The experimental modal analysis was conducted on three full-sized medium-density fiberboard (MDF) and three full-sized particleboard (PB) panels of three different thicknesses (12, 15, and 18 mm). The natural frequencies and mode shapes of the first nine modes of vibration were determined. Results from experimental modal testing were compared with the results of a theoretical modal analysis. A sensitivity analysis was performed to identify the sensitive modes for calculating E (major axis: E_x and minor axis: E_y) and the in-plane shear modulus (G_xy) of the panels. Mode shapes of the MDF and PB panels obtained from modal testing are in a good agreement with those from theoretical modal analyses. A strong linear relationship exists between the measured natural frequencies and the calculated frequencies. The frequencies of modes (2, 0), (0, 2), and (2, 1) under the four-node support condition were determined as the characteristic frequencies for calculation of E_x, E_y, and G_xy of full-sized WCPs. The results of this study indicate that the four-node support can be used in free vibration test to determine the elastic properties of full-sized WCPs. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

7740 KiB

Open AccessArticle

Crack Extension and Possibility of Debonding in Encapsulation-Based Self-Healing Materials

by Wenting Li, Zhengwu Jiang and Zhenghong Yang

Materials 2017, 10(6), 589; https://doi.org/10.3390/ma10060589 - 27 May 2017

Cited by 12 | Viewed by 4063

Abstract

The breakage of capsules upon crack propagation is crucial for achieving crack healing in encapsulation-based self-healing materials. A mesomechanical model was developed in this study to simulate the process of crack propagation in a matrix and the potential of debonding. The model used [...] Read more.

The breakage of capsules upon crack propagation is crucial for achieving crack healing in encapsulation-based self-healing materials. A mesomechanical model was developed in this study to simulate the process of crack propagation in a matrix and the potential of debonding. The model used the extended finite element method (XFEM) combined with a cohesive zone model (CZM) in a two-dimensional (2D) configuration. The configuration consisted of an infinite matrix with an embedded crack and a capsule nearby, all subjected to a uniaxial remote tensile load. A parametric study was performed to investigate the effect of geometry, elastic parameters and fracture properties on the fracture response of the system. The results indicated that the effect of the capsule wall on the fracture behavior of the matrix is insignificant for t_c/R_c ≤ 0.05. The matrix strength influenced the ultimate crack length, while the Young’s modulus ratio E_c/E_m only affected the rate of crack propagation. The potential for capsule breakage or debonding was dependent on the comparative strength between capsule and interface (S_c/S_int), provided the crack could reach the capsule. The critical value of S_c_,cr/S_int,crwas obtained using this model for materials design. Full article

(This article belongs to the Special Issue Modeling and Simulation of Advanced Composite Materials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Modeling and Simulation of Advanced Composite Materials

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI