Joong-Jin Kim, Jin-Hwe Kweon¹, Jin-Ho Choi, Jong-Su Han

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 41-42, 2009, DOI:10.3970/icces.2009.012.041

Abstract Target-drone is an unmanned remotely controlled aerial vehicle and usually used for shooting training for anti-aircraft screws. Traditional target-drones have been generally manufactured from aluminum and/or wood. Recently, composite materials have been replacing them in virtue of their high strength-to-weight and stiffness-to-weight ratios. In particular, glass fiber-based composite materials are popular for the target-drone level vehicles because of the material cost and fabrication convenience.
In this paper, as a part of the development activities for a complete target-drone vehicle, the stress analysis results are presented for a 685cc engine target-drone composite aerial vehicle wing. Composite materials used are H612 and… More >

V.C. Santos¹, P.S. Lopes¹, R. Gärtner², A.B. Jorge¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 53-58, 2007, DOI:10.3970/icces.2007.004.053

Abstract This work presents an approach for weight and reliability optimization of aeronautical armors. Military and police helicopters are usually exposed to highly risky situations, with a high probability for these aircrafts to be hit by projectiles. In this context, floor aircraft armor can be used to protect the crews' lives. However, the armoring of an aircraft causes an increase in weight. If this extra weight is poorly arranged, the changes in aircraft centroid position may even destabilize the aircraft. Thus, it is essential to design an armor not only to protect the aircraft, but also not to conflict with aircraft… More >

M. Khennache^1,*, A. Mahieu¹, M. Ragoubi¹, S. Taibi¹, C. Poilâne², N. Leblanc¹

Journal of Renewable Materials, Vol.7, No.9, pp. 821-838, 2019, DOI:10.32604/jrm.2019.06772

Abstract In France, the use of flax fibers as reinforcement in composite materials is growing exponentially in the automotive sector, thanks to their good physicochemical properties, environmental reasons, health neutrality and due to the European Council Directives on the reuse, recycling and valorization of car components and materials. The aim of our study is to investigate biochemical, physicochemical, and mechanical properties of technical flax fibers to evaluate the impact of transformation processes (scutching, hackling, and homogenization) on final properties of associated composite materials. Different chemical analysis such as Van Soest (biochemical fraction measurement), FTIR (Fourier Transform InfraRed spectroscopy), and XRD (X-ray… More >

P. Raghavan¹, S. Ghosh²

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 151-170, 2004, DOI:10.3970/cmes.2004.005.151

Abstract This paper presents an adaptive multi-level computational model that combines a conventional displacement based finite element model with a microstructural Voronoi cell finite element model for multi-scale analysis of composite structures with non-uniform microstructural heterogeneities as obtained from optical or scanning electron micrographs. Three levels of hierarchy, with different resolutions, are introduced in this model to overcome shortcomings posed by modeling and discretization errors. Among the three levels are: (a) level-0 of pure macroscopic analysis; (b) level-1 of macro-micro coupled modeling, used for signaling the switch over from macroscopic analyses to pure microscopic analyses; and (c) level-2 regions of pure… More >

Hiroshi Okada¹, Yasuyoshi Fukui¹, Noriyoshi Kumazawa¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.2, pp. 135-150, 2004, DOI:10.3970/cmes.2004.005.135

Abstract A method to obtain the effective mechanical properties of particulate composite materials is presented in this paper. The methodology is based on the boundary element method (BEM) coupled with analytical solutions for ellipsoidal inclusions such as Eshelby's tensor. There is no numerical integration for the surfaces or the domains of distributed particles, and, therefore, proposed technique is very efficient. Homogenization analysis based on representative volume element (RVE) is carried out considering a unit cell containing many particles (up to 1000). By using a conventional BEM approach (i.e., multi-region BEM), it would be extremely difficult to analyze such a large RVE,… More >

Yajie Sun^1,2,*, Yanqing Yuan², Qi Wang², Sai Ji^1,2, Lihua Wang³, Shaoen Wu⁴, Jie Chen², Qin Zhang²

Journal of Quantum Computing, Vol.1, No.1, pp. 1-8, 2019, DOI:10.32604/jqc.2019.05788

Abstract A method is proposed based on the transmissibility function and the Online Sequence Extreme Learning Machine (OS-ELM) algorithm, which is applied to the impact damage of composite materials. First of all, the transmissibility functions of the undamaged signals and the damage signals at different points are calculated. Secondly, the difference between them is taken as the damage index. Finally, principal component analysis (PCA) is used to reduce the noise feature. And then, input to the online sequence limit learning neural network classification to identify damage and confirm the damage location. Taking the amplitude of the transmissibility function instead of the… More >

Swarnalata Sahoo^1,2*, Hemjyoti Kalita¹, Smita Mohanty^1,2, Sanjay Kumar Nayak^1,2

Journal of Renewable Materials, Vol.6, No.1, pp. 117-125, 2018, DOI:10.7569/JRM.2017.634155

Abstract In the current work, we have synthesized vegetable oil-based polyurethane-OMMT clay nanocomposite (PUNC) adhesive with the incorporation of different wt% of organically modified nanoclay (1 to 5 wt%) into the biobased polyurethane (PU) matrix through in-situ polymerization process via ultrasonication method. At the initial stage, PU adhesive was prepared using polyol and partially biobased aliphatic isocyanate, wherein polyol was derived from the transesterified castor oil using ethylene glycol. The formation of PU and PUNC adhesive was confirmed using Fourier transform infrared (FTIR) spectroscopy analysis. The tensile strength of PU with different wt% of nanoclay was determined and the analysis showed… More >

Meriem Fehri^1,2, Rachid Robleh Ragueh¹, Alexandre Vivet^1*, Fakhreddine Dammak², Mohamed Haddar²

Journal of Renewable Materials, Vol.5, No.1, pp. 38-47, 2017, DOI:10.7569/JRM.2016.634123

Abstract The purpose of this work is the improvement of flax fiber-reinforced composites obtained by vacuum molding in order to encourage their insertion into industrial products. The relatively high degree of porosity in these kinds of composites, due to the lack of compatibility between epoxy matrix and flax fibers and the hydrophilicity of flax fiber, remains a major constraint to their use in the industrial world. Hence, we have used a combination of carbon fibers with those of flax in order to optimize the properties of the assembly. Several stacking sequences have been tested in order to analyze the influence of… More >

Heather L. Buckley^1*, Caitlin H. Touchberry², Jonathan P. McKinley², Zachary S. Mathe¹, Hurik Muradyan¹, Hannah Ling², Raj P. Fadadu¹, Martin J. Mulvihill¹, Susan E. Amrose²

Journal of Renewable Materials, Vol.5, No.1, pp. 1-13, 2017, DOI:10.7569/JRM.2016.634109

Abstract Waste cardboard is an underutilized resource that can be redirected for the creation of safer and higher quality building materials for low-income housing in the developing world, as well as to produce better materials for indoor environments in developed-world contexts. Using a renewable biobased binder and benign additives, we have improved the water resistance of a cardboard-based composite material, overcoming one of the major barriers to scaling and adoption of this class of materials. Resistance to water uptake was significantly increased with several additives and was increased over 900-fold in the best case. Strength and water uptake over time are… More >

Itxaso Algar¹, Clara Garcia-Astrain¹, Alba Gonzalez², Loli Martin³, Nagore Gabilondo¹, Aloña Retegi^1*, Arantxa Eceiza^1*

Journal of Renewable Materials, Vol.4, No.1, pp. 57-65, 2016, DOI:10.7569/JRM.2015.634124

Abstract Bacterial cellulose/montmorillonite (BCMMT) hybrid bionanocomposite membranes were prepared by in-situ assembling or one-step biosynthesis process. The presence of MMT in BC membranes was confi rmed by thermogravimetric analysis and quantifi ed by mass spectrometry, resulting in bionanocomposites with MMT contents between 7–13 wt%. The incorporation of MMT during BC biosynthesis modifi ed BC morphology and led to lower porosity, even though higher water holding capacity was achieved. Bionanocomposites showed improved thermal stability and water vapor and oxygen gas barrier properties up to 70 and 80% with respect to neat BC membranes. This improvement was related to the tortuous path of… More >