Open Access

ABSTRACT

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 >

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702

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ABSTRACT

Christos C. Chamis¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 59-66, 2007, DOI:10.3970/icces.2007.004.059
Abstract A formal procedure for the probabilistic design evaluation of a composite structure is described. The uncertainties in all aspects of a composite structure (constituent material properties, fabrication variables, structural geometry, and service environments, etc.), which result in the uncertain behavior in the composite structural responses, are included in the evaluation. The probabilistic evaluation consists of: (1) design criteria, (2) modeling of composite structures and uncertainties, (3) simulation methods, and (4) the decision-making process. A sample case is presented to illustrate the formal procedure and to demonstrate that composite structural designs can be probabilistically evaluated with accuracy and efficiency. More >

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883

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765

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ABSTRACT

Pramod Kumar¹, Rakesh Chandra¹, S.P. Singh²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 67-72, 2007, DOI:10.3970/icces.2007.004.067
Abstract Polymers composite are modeled as fiber, interphase and matrix. Interphase properties are very crucial for bonding between fiber and matrix. Interphase can be strong and weak depending upon its properties. Damping of composite material depends on interphase properties and required damping can be obtained by varying the properties of interphase. In this paper three phase mathematical model has been proposed for the evaluation of damping incorporating the effect of fiber packing. Effect of interphase has been analysed for the longitudinal loss factor, transverse loss factor, transverse shear loss factor and longitudinal shear loss factor. Results obtained by modeling fiber reinforced… More >

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910

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779

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ABSTRACT

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 >

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934

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682

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ABSTRACT

Waruna Seneviratne¹, John Tomblin², Suranga Gunawardana³
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 81-86, 2007, DOI:10.3970/icces.2007.004.081
Abstract An experimental study was conducted to investigate the use of fracture mechanics to predict failure initiation of adhesive joints. Most practical plane fracture problems are mixed mode and failure initiation of adhesive joints is a result of such conditions. It is widely accepted that a useful method for characterizing the toughness of bonded joints is to measure the fracture toughness; energy per unit area needed to produce failure. For a given adhesive, mode mixity has a dependency towards fracture toughness and fracture toughness is directly associated with stress. Main goal in this investigation was to demonstrate the capability of utilizing… More >

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927

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905

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Y. Kato, Y. Yamamura
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 87-92, 2007, DOI:10.3970/icces.2007.004.087
Abstract The purpose of this study is to investigate the deformational behavior and strength of the catheter which is made from the soft nylon resin and is reinforced with thin stainless wires called braid. When we image the usage conditions of catheter in the actual surgical operation, it is expected that the multi-axial loading for tension, torsion and the bending are applied and deformations occurring in the catheter become very complicated. As the first step of this study to reveal these phenomena, the combined loadings for tension and torsion are chosen as the subject of this study and we carry out… More >

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813

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676

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A. Cazzani¹, E. Garusi², A. Tralli³, S.N. Atluri⁴
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 93-122, 2007, DOI:10.3970/icces.2007.004.093
Abstract Fibre-reinforced plates and shells are finding an increasing interest in engineering applications. Consequently, efficient and robust computational tools are required for the analysis of such structural models. As a matter of fact, a large amount of laminate finite elements have been developed and incorporated in most commercial codes for structural analysis. In this paper a new laminate hybrid assumed-strain plate element is derived within the framework of the First-order Shear Deformation Theory (i.e. assuming that particles of the plate originally lying along a straight line which is normal to the undeformed middle surface remain aligned along a straight line during… More >

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931

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745

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H.K. Lee¹, J.W. Ju²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 123-128, 2007, DOI:10.3970/icces.2007.004.123
Abstract This paper summarizes the results of an analytical study (Lee and Ju, 2006) conducted to develop an approximate micromechanical analytical formulation to accommodate all the possible second-order, ensemble-volume averaged perturbations due to the interactions of randomly located microcracks and inclusions in brittle composites. To account for the three-dimensional effects of interactions among constituents, an approximate solution of a micromechanical framework considering the pairwise microcrack interactions, the pairwise inclusion interactions and the interactions between microcracks and inclusions have been systematically presented. The proposed pairwise interacting micromechanical damage models are compared to illustrate the influence of constituent interactions on effective elastic-damage moduli… More >

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825

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653

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ABSTRACT

J. Gajdošík¹, M. Šejnoha¹, J. Zeman¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 129-136, 2007, DOI:10.3970/icces.2007.004.129
Abstract Rock masses with relatively high concentration of discontinuities or joints are considered. Being aware of limitations of various averaging techniques such as the self consistent or Mori-Tanaka methods in providing reliable estimates of generally nonlinear macroscopic response of jointed rock masses, the paper introduces a notion of statistically equivalent periodic unit cell (SEPUC). Such a unit cell contains, in order to reduce the problem complexity, of the orders of magnitude less number of joints in comparison with the actual material system. In analogy with two-phase composites, the SEPUC is expected to be found in a statistical sense by matching suitable… More >

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634