Harald Berger¹, Ulrich Gabbert², Reinaldo Rodriguez-Ramos³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.2, pp. 127-129, 2009, DOI:10.3970/icces.2009.009.127

Abstract Piezoelectric materials have the property of converting electrical energy into mechanical energy and vice versa. This reciprocity in the energy conversion makes piezoelectric ceramics very attractive for use as sensors and actuators. By combining piezoelectric fibers with passive non-piezoelectric polymer composites with superior properties can be created. But for design of such smart micro-macro structures homogenization techniques are necessary to describe the overall behavior of piezocomposites expressed by effective material coefficients.
A number o fnumerical and analytical methods have been developed to estimate the effective coefficients. Although analytical homogenization methods provide excellent results it is difficult to extend them to… More >

H. T. Wang¹, Z. H. Yao²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.2, pp. 95-96, 2009, DOI:10.3970/icces.2009.009.095

Abstract Carbon nanotubes (CNTs) may provide ultimate enhancement in stiffness and str\discretionary {-}{}{}ength for composite materials. This paper presents a rigid-fiber-based boundary integral equation formulation for the numerical simulation of debonding process and the corresponding strength of CNT reinforced composites. The CNT/matrix interfaces are assumed to fail when the interfacial shear force reaches a prescribed threshold, and the CNTs and matrix are considered to be detached in the failed areas. The matrix with one or several tens of originally well-bonded CNTs is subjected to an incremental tensile load and the effective stress-strain relations are readily obtained by the introduction of CNT/matrix… More >

Lingjie Yu^1,2, Guanlin Wang¹, Chao Zhi¹, Bugao Xu^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 365-372, 2019, DOI:10.32604/cmes.2019.04494

Abstract A fibrous filtering material is a kind of fiber assembly whose structure exhibits a three-dimensional (3D) network with dense microscopic open channels. The geometrical/morphological attributes, such as orientations, curvatures and compactness, of fibers in the network is the key to the filtration performance of the material. However, most of the previous studies were based on materials’ 2D micro-images, which were unable to accurately measure these important 3D features of a filter’s structure. In this paper, we present an imaging method to reconstruct the 3D structure of a fibrous filter from its optical microscopic images. Firstly, a series of images of… More >

Ch,ra S. Yerramalli¹, Anthony M. Waas²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 1-16, 2004, DOI:10.3970/cmes.2004.006.001

Abstract Results from a 3D finite element based study of the compression response of unidirectional fiber reinforced polymer matrix composites (FRPC) are presented in this paper. The micromechanics based study was used to simulate the compressive response of glass and carbon fiber reinforced polymer matrix composites, with a view to understanding the effect of fiber diameter on compression strength. Results from the modeling and simulation indicate the presence of a complex three dimensional stress state in the matrix of the FRPC. Results from the simulation highlight the role of fiber diameter on the compressive response of FRPC. In particular, it is… More >

Phornwalan Nanthananon¹, Manus Seadan², Sommai Pivsa-Art³, Hiroyuki Hamada⁴, Supakij Suttiruengwong^1,*

Journal of Renewable Materials, Vol.6, No.6, pp. 573-583, 2018, DOI:10.32604/JRM.2018.00129

Abstract Poor interfacial adhesion between biobased thermoplastics and natural fibers is recognized as a major drawback for biocomposites. To be applicable for the large-scale production, a simple method to handle is of importance. This work presented poly(lactic acid) (PLA) reinforced with short-fiber and three reactive agents including anhydride and epoxide groups were selected as compatibilizers. Biocomposites were prepared by one-step melt-mixing methods. The influence of reactive agents on mechanical, dynamic mechanical properties and morphology of PLA biocomposites were investigated. Tensile strength and storage modulus of PLA biocomposites incorporated with epoxide-based reactive agent was increased 13.9% and 37.4% compared to non-compatibilized PLA… More >

Marwa Abida^1,2, Jamel Mars^3,*, Florian Gehring¹, Alexandre Vivet¹, Fakhreddine Dammak³

Journal of Renewable Materials, Vol.6, No.5, pp. 464-476, 2018, DOI:10.32604/JRM.2018.01897

Abstract Based on experimental test results, flax fiber reinforced polymer composites are characterized by nonlinear visco-elastoplastic behavior. The aim of this work is to model the quasi-unidirectional flax fiber reinforced composite behavior through a three dimensional formulation with orthotropic elasticity and orthotropic plasticity using Hill criterion. The isotropic hardening and Johnson Cook parameters are identified from unidirectional tensile tests at different strain rates. The adjustment of Hill’s yield criterion is developed based on yield stresses obtained in tensile tests at different directions. The numerical integration of the constitutive equations is implemented in a user-defined material, UMAT subroutines for the commercial finite… More >

Ahmad Safwan¹, Mohammad Jawaid^1*, Mohamed T. H. Sultan^1,2, Azman Hassan³

Journal of Renewable Materials, Vol.6, No.5, pp. 529-535, 2018, DOI:10.7569/JRM.2018.634103

Abstract The application of natural fibers as reinforcement in composite material has increased due to environmental concerns, low cost, degradability and health concerns. The purpose of this study is to identify the best type of bamboo fibers to be used as reinforcement for kenaf (K)/bamboo hybrid composite. There were three types of bamboo fibers evaluated in this study which include bamboo mat (B), bamboo fabric (BF) and bamboo powder (BP). Chemical composition of B, BF, BP and K fibers were analyzed in this study. The effect of different types of bamboo fibers on tensile, impact, and morphological properties were investigated. The… More >

A. Atiqah¹, M. Jawaid^1,*, S. M. Sapuan^1,2, M. R. Ishak³

Journal of Renewable Materials, Vol.6, No.5, pp. 477-492, 2018, DOI:10.7569/JRM.2017.634188

Abstract The aim of the present study was to develop sugar palm fiber (SPF) reinforced thermoplastic polyurethane (TPU) composites and to investigate the effects of fiber surface modification by 2% silane treatment and fiber loading (0, 10, 20, 30, 40 and 50 wt%) on the mechanical and thermal properties of the obtained composites. Surface treatment was employed to improve the fiber-matrix interface, which was expected to boost the mechanical strength of the composites, in terms of tensile, flexural and impact properties. Thermal properties were also investigated by thermal gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) to assess the thermal stability… More >

S. Michałowski¹, M. A. Mosiewicki^2*, M. Kuran´ska¹, M. I. Aranguren², A. Prociak¹

Journal of Renewable Materials, Vol.6, No.4, pp. 426-437, 2018, DOI:10.7569/JRM.2017.634163

Abstract Elastomeric polyurethanes were prepared from a reference polyurethane system modified with biobased polyols synthesized using rapeseed or palm oils. The reference material was modified by replacement of the commercial polyol by 10% of biopolyols and also by addition of sisal fibers up to 5 wt%. The higher functionality of the biopolyols increased the crosslinking density of the networks and this was reflected by an increase in hardness and a decrease in water absorption. The effect of the sisal fibers mainly improved the mechanical and thermomechanical properties of the system with rapeseed oil because of good dispersion and strong fiber-matrix interaction.… More >

M. Asim¹, M. Jawaid^1,2*, M. Nasir³, N. Saba¹

Journal of Renewable Materials, Vol.6, No.4, pp. 383-393, 2018, DOI:10.7569/JRM.2017.634162

Abstract This study deals with the analysis of dynamic mechanical, thermal and flammability properties of treated and untreated pineapple leaf fiber (PALF) and kenaf fiber (KF) phenolic composites. Results indicated that storage modulus was decreased for all composites with increases in temperature and pattern of slopes for all composites, having almost the same values of E' at glass transition temperature (Tg). The peak of the loss modulus of pure phenolic composites was shown to be much less. After the addition of kenaf/PALF, peaks were higher and shifted towards a high temperature. The Tan delta peak height was low for pure phenolic… More >