Hedieh Teymoorzadeh¹, Denis Rodrigue^2,*

Journal of Renewable Materials, Vol.2, No.4, pp. 270-277, 2014, DOI:10.7569/JRM.2014.634127

Abstract This work investigates the effect of the addition of fl ax fi ber (15, 25, and 40 wt%) on the mechanical, morphological, rheological, and thermal properties of polylactic acid (PLA). In the fi rst step, no coupling agent was used to produce fully biodegradable and biobased composites. In particular, fl exural tests were performed on the composites to evaluate their mechanical properties, while density, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and rheological tests were also carried out. Scanning electron microscopy images (SEM) show good fl ax fi ber dispersion in the PLA matrix along More >

M. Tazi¹, F. Erchiqui^1,*, F.Godard¹, H. Kaddami²

Journal of Renewable Materials, Vol.2, No.4, pp. 258-263, 2014, DOI:10.7569/JRM.2014.634120

Abstract This article evaluates the mechanical properties and biodegradability of wood-plastic composite materials made from sawdust and thermoplastic polymer (HDPE). For the preparation of the composites, sawdust in different proportions with Maleic Anhydride grafted Polyethylene (MAPE) as the coupling agent was used. The mechanical properties and biodegradability of the biocomposites were successively characterized. The results indicate that adding sawdust particles to a polymer matrix improves the mechanical strength and stiffness of composites. The tensile strength of a composite with 3% coupling agent was improved by 13%, 34% and 54% respectively when 20%, 30% and 40% wood… More >

Amar Boukerrou^*, Dalila Hammiche, Djidjelli Hocine, Hassina Aouat

Journal of Renewable Materials, Vol.2, No.4, pp. 249-257, 2014, DOI:10.7569/JRM.2014.634119

Abstract The lack of compatibility between cellulose fi bers and some polymers, such as thermoplastics, is due on one hand to the hydrophilic nature of the vegetable fi bers and on the other hand to the hydrophobic character of the matrix. This incompatibility induces bad dispersion of the fi bers and the formation of a heterogeneous material with mechanical properties which are not very satisfactory. The scope of this article is to describe the possibility of using Olive Husk Flour (OHF) as reinforcement in the elaboration of a composite material based on polyvinyl chloride (PVC). In More >

B.J. Yang¹, K.J. Cho¹, G.M. Kim¹, H.K. Lee^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.5, pp. 343-365, 2014, DOI:10.3970/cmes.2014.103.343

Abstract The addition of carbon nanotubes (CNTs) to a matrix material is expected to lead to an increase in the effective electrical properties of nanocomposites. However, a CNT entanglement caused by the matrix viscosity and the high aspect ratio of the nanotubes often inhibits the formation of a conductive network. In the present study, the micromechanics-based model is utilized to investigate the effect of CNT agglomeration on the electrical conductivity and percolation threshold of nanocomposites. A series of parametric studies considering various shapes and curviness distributions of CNTs are carried out to examine the effects of More >

L. Rodríguez-Tembleque¹, M.H. Aliabadi²

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.3, pp. 183-210, 2014, DOI:10.3970/cmes.2014.102.183

Abstract This work presents new contact constitutive laws for friction and wear modelling in fiber-reinforced plastics (FRP). These laws are incorporated to a numerical methodology which allows us to solve the contact problem taking into account the anisotropic tribological properties on the interfaces. This formulation uses the Boundary Element Method for computing the elastic influence coefficients. Furthermore, the formulation considers micromechanical models for FRP that also makes it possible to take into account the fiber orientation relative to the sliding direction, the fiber volume fraction, the aspect ratio of fibers, or the fiber arrangement. The proposed More >

K. S. Alan¹

CMC-Computers, Materials & Continua, Vol.44, No.1, pp. 1-21, 2014, DOI:10.3970/cmc.2014.044.001

Abstract In the framework of the piecewise homogeneous body model with the use of the three-dimensional geometrically nonlinear exact equations of the theory of elasticity, the method developed for the determination of the stress distribution in the nanocomposites with unidirectional locally curved and hollow nanofibers is used to investigate the normal stresses acting along the nanofibers. Furthermore, it is assumed that the body is loaded at infinity by uniformly distributed normal forces which act along the nanofibers and the crosssection of the nanofibers and normal to its axial line, is a circle of constant radius along More >

Yu Miao¹, Zhe Chen¹, Qiao Wang^1,2, Hongping Zhu¹

CMC-Computers, Materials & Continua, Vol.43, No.1, pp. 49-74, 2014, DOI:10.3970/cmc.2014.043.049

Abstract In this paper, an improved multi-domain model based on the hybrid boundary node method (Hybrid BNM) is proposed for mechanical analysis of 3D composites. The Hybrid BNM is a boundary type meshless method which based on the modified variational principle and the Moving Least Squares (MLS) approximation. The improved multi-domain model can reduce the total degrees of freedom (DOFs) compared with the conventional multi-domain solver. It is very suitable for the inclusion-based composites, especially for the composites when the inclusions are solid and totally embedded in the matrix domain. Numerical examples are presented to verify More >

S. Zhao¹, Zichun Yang^1,2, X. G. Zhou³, X. Z. Ling⁴, L. S. Mora⁵, D. Khoshkhou⁶, J. Marrow⁵

CMC-Computers, Materials & Continua, Vol.42, No.2, pp. 103-124, 2014, DOI:10.3970/cmc.2014.042.103

Abstract Continuous SiC fiber reinforced SiC matrix composites (SiC/SiC) have been studied and developed for high temperature and fusion applications. Polymer impregnation and pyrolysis (PIP) is a conventional technique for fabricating SiC/SiC composites. In this research, KD-1 SiC fibers were employed as reinforcements, a series of coatings such as pyrocarbon (PyC), SiC and carbon nanotubes (CNTs) were synthesized as interphases, PCS and LPVCS were used as precursors and SiC/SiC composites were prepared via the PIP method. The mechanical properties of the SiC/SiC composites were characterized. Relationship between the interphase shear strength and the fracture toughness of More >

Anna Y. Matveeva¹, Helmut J. Böhm², Grygoriy Kravchenko², Ferrie W. J. van Hattum¹

CMC-Computers, Materials & Continua, Vol.42, No.1, pp. 1-23, 2014, DOI:10.3970/cmc.2014.042.001

Abstract This paper presents a comparison of different finite element approaches to modelling polymers reinforced with wavy, hollow fibres with the aim of predicting the effective elastic stiffness tensors of the composites. The waviness of the tubes is described by sinusoidal models with different amplitude-to-wavelength parameters. These volume elements are discretized by structured volume meshes onto which fibres in the form of independently meshed beam, shell or volume elements are superimposed. An embedded element technique is used to link the two sets of meshes. Reference solutions are obtained from conventional three-dimensional volume models of the same More >

Qiubao Ouyang¹, Di Zhang^1,2, Xinhai Zhu³, Zhidong Han³

CMC-Computers, Materials & Continua, Vol.41, No.1, pp. 37-54, 2014, DOI:10.3970/cmc.2014.041.037

Abstract The present work is to investigate the failure mechanisms in the deformation of silicon carbide (SiC) particle reinforced aluminum Metal Matrix Composites (MMCs). To better deal with crack growth, a new numerical approach: the MLPG-Eshelby Method is used. This approach is based on the meshless local weak-forms of the Noether/Eshelby Energy Conservation Laws and it achieves a faster convergent rate and is of good accuracy. In addition, it is much easier for this method to allow material to separate in the material fracture processes, comparing to the conventional popular FEM based method. Based on a… More >