Nian Li^*

Structural Durability & Health Monitoring, Vol.13, No.4, pp. 331-346, 2019, DOI:10.32604/sdhm.2019.07521

Abstract The investigation focusing on the mechanical behaviors at the microstructural level in composite materials can provide valuable insight into the failure mechanisms at larger scales. A micromechanics damage model which comprises the coupling of the matrix constitutive model and the cohesive zone (CZM) model at fiber-matrix interfaces is presented to evaluate the transverse tensile damage behaviors of unidirectional (UD) fiber-reinforced polymer (FRP) composites. For the polymeric matrix that exhibits highly non-linear mechanical responses, special focus is paid on the formulation of the constitutive model, which characterizes a mixture of elasticity, plasticity as well as damage. The proposed constitutive model includes… More >

M. Noryani^{1, 3, 5}, S. M. Sapuan^{1, 2,*}, M. T. Mastura^{4, 5}, M. Y. M. Zuhri¹, E. S. Zainudin¹

Journal of Renewable Materials, Vol.7, No.11, pp. 1165-1179, 2019, DOI:10.32604/jrm.2019.07691

Abstract Material selection has become a critical part of design for engineers, due to availability of diverse choice of materials that have similar properties and meet the product design specification. Implementation of statistical analysis alone makes it difficult to identify the ideal composition of the final composite. An integrated approach between statistical model and micromechanical model is desired. In this paper, resultant natural fibre and polymer matrix from previous study is used to estimate the mechanical properties such as density, Young’s modulus and tensile strength. Four levels of fibre loading are used to compare the optimum natural fibre reinforced polymer composite… More >

De-Shin Liu, Zhen-Wei Zhuang, Cho-Liang Chung

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.019.039

Abstract A two-dimensional heterogeneous hybrid moisture element method (HHMEM) for modeling transient moisture diffusion in permeable fiber-reinforced polymer composites is proposed in this paper.
The HHMEM scheme is based on a heterogeneous hybrid moisture element (HHME), whose properties are determined by equivalent moisture capacitance and conductance matrixes calculated using the conventional finite element formulation with the similarity mass/stiffness property and matrix condensing operations. A coupled HHME-FE scheme is developed and implemented in computer codes MATLAB to analyze the transient moisture diffusion characteristics of polymeric composite materials containing multiple permeable fibers. The analysis commences by comparing the performance of the proposed… More >

S. Gururaja¹, M. Ramulu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 73-80, 2007, DOI:10.3970/icces.2007.004.073

Abstract Uni-Directional Fiber-Reinforced Plastic (UD-FRP) laminates have been modeled as a quasi-homogeneous monoclinic half-space subjected to an inclined load at the surface. Complete closed form stress-fields derived previously [1] based on Lekhtinskii's formulation [2] in conjunction with the principle of analytical continuation [3] were used to study the stress-response in relation to a few parameters identified, namely, fiber-orientation, load inclination angle and spatial coordinates with respect to line load application position in the half-space domain. More >

A. Ramírez-Jiménez^1*, S. Hernández López¹, E. Bucio², E. Vigueras Santiago¹

Journal of Renewable Materials, Vol.5, No.2, pp. 132-144, 2017, DOI:10.7569/JRM.2016.634138

Abstract Epoxidized linseed oil (ELO) was synthesized and functionalized with propargylamine (PA) or 3-ethynylaniline (EA) and the products were crosslinked to obtain the diacetylene-functionalized epoxidized linseed oil polymers which were used as matrices in the preparation of the composites with multiwalled carbon nanotubes (MWCNTs). Electrical resistance at percentages between 4 and 20 wt/wt% of filler was measured and the percolation threshold was calculated, obtaining 1.2 and 1.7% for the composites with EA and PA respectively. Low critical concentration evidenced a good dispersion of the MWCNTs without necessity of any modification. The final products were used in the sensing of acetone, chloroform… More >

De-Shin Liu¹, Zhen-Wei Zhuang¹, Shaw-Ruey Lyu^2,3, Cho-Liang Chung⁴, Pai-Chen Lin¹

CMC-Computers, Materials & Continua, Vol.26, No.2, pp. 111-136, 2011, DOI:10.3970/cmc.2011.026.111

Abstract This study proposes a two-dimensional heterogeneous hybrid moisture element method (HHMEM) for modeling transient moisture diffusion in permeable fiber-reinforced polymer composites.
The HHMEM scheme is based on a heterogeneous hybrid moisture element(HHME), with properties determined through an equivalent hybrid moisture capacitance/conductance matrix. This matrix was calculated using the conventional finite element formulation in space discretization as well as the θ-method in time discretization with similar mass/stiffness properties and matrix condensing operations. A coupled HHME-FE scheme was developed and implemented in computer code MATLAB in order to analyze the transient moisture diffusion characteristics of composite materials containing multiple permeable fibers. The… More >

L. Rodríguez-Tembleque¹, A. Sáez¹, F.C. Buroni¹

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.2, pp. 131-158, 2013, DOI:10.3970/cmes.2013.096.131

Abstract A boundary element based formulation is applied to study numerically the tribological behavior of fiber-reinforced plastics (FRP) under different frictional contact conditions, taking into account the micromechanics of FRP. Micromechanical models presented consider continuous and short fiber reinforced plastics configurations. The Boundary Element Method (BEM) with an explicit approach for fundamental solutions evaluation is considered for computing the elastic influence coefficients. Signorini’s contact conditions and an orthotropic law of friction on the potential contact zone are enforced by contact operators over the augmented Lagrangian. The proposed methodology is applied to study carbon FRP under frictional contact. The obtained numerical results… More >

A.N. Guz¹, J.J.Rushchitsky¹, I.A.Guz²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 139-156, 2008, DOI:10.3970/cmes.2008.026.139

Abstract The basic approach is offered for problems of nanocomposites and their mechanical properties, which includes a short review of modern problems in nanomechanics of materials. The fibrous carbon-polymer composites with carbon or graphite microfibers or carbon nanotubes are especially discussed. The basic model of the linear or nonlinear elastically deforming micro- and nanocomposites is considered. Within the framework of this model, the comparative computer modeling is performed. The modeling permits to observe the features in prediction of values of basic mechanical constants. These results are utilized on next step of modeling -- studying the peculiarities of wave propagation in particular… More >

Oliver K. Johnson¹, Calvin J. Gardner¹, David T. Fullwood¹, Brent L.Adams¹, Nathan Hansen², George Hansen²

CMC-Computers, Materials & Continua, Vol.15, No.2, pp. 87-112, 2010, DOI:10.3970/cmc.2010.015.087

Abstract A novel nickel nanostrand-silicone composite material at an optimized 15 vol% filler concentration demonstrates a dramatic piezoresistive effect with a negative gauge factor (ratio of percent change in resistivity to strain). The composite volume resistivity decreases in excess of three orders of magnitude at a 60% strain. The piezoresistivity does decrease slightly as a function of cycles, but not significantly as a function of time. The material's resistivity is also temperature dependent, once again with a negative dependence.
The evidence indicates that nickel strands are physically separated by matrix material even at high volume fractions, and points to a charge… More >