Raimund Rolfes, Matthias Vogler, Benedikt Kriegesmann¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 43-44, 2009, DOI:10.3970/icces.2009.012.043

Abstract Fiber composite structures are usually thin-walled and hence, prone to buckling. Thus, beside material failure also stability problems have to be considered.

Thin-walled cylindrical composite shells buckle in the elastic region and thus, there is no need to consider material non-linearities or material failure. Never the less, a robust design guide for composite shells does not exist until today. The most frequently guideline is NASA SP-8007, which gives an empirical based knockdown factor. Because this guideline is not intended for composite shells and it turned out to be very conservative in numerous cases several approaches… More >

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… More >

Yong-bin Park¹, Jin-Hwe Kweon¹, Jin-Ho Choi¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.2, pp. 39-40, 2009, DOI:10.3970/icces.2009.012.039

Abstract This paper addresses experimental results on the strength of single-lap composite bonded joints with different manufacturing methods and configurations. The joints were fabricated with 4 different methods; Co-curing with additional adhesive (CCA) and without additional adhesive (CCN) between composite adherends, Co-bonding (COB) and secondary bonding (SEB). Joints have 5 different overlap lengths(l), 3 different lay-up patterns and 4 different thicknesses(t), respectively. Width of the joints(w) is constant at 25.4 mm. A total of 389 single-lap specimens were tested in tension. In the test to examine the effect of manufacturing methods and overlap lengths, the joint… More >

L. Donati, L. Tomesani

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 37-38, 2009, DOI:10.3970/icces.2009.012.037

Abstract In recent years aluminum extruded hollow profiles are increasingly used in near-net shape manufacturing processes such as bending and hydroforming; in fact, by applying these secondary processes, it is possible to obtain very high complex parts, especially for the transport industry. It is known that hollow profiles obtained by direct hot extrusion necessarily have some longitudinal welding lines (so called seam welds) produced inside the die and it is common experience, during secondary forming processes, the appearance of early cracking in proximity of those lines [1,2]. At the same time, the direct hot extrusion is… More >

J. Sladek¹, V. Sladek¹, P. Solek²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 35-36, 2009, DOI:10.3970/icces.2009.012.035

Abstract Functionally graded materials are multi-phase materials with the phase volume fractions varying gradually in space, in a pre-determined profile. This results in continuously graded mechanical properties at the (macroscopic) structural scale. Often, these spatial gradients in material behaviour render FGMs as superior to conventional composites. FGMs possess some advantages over conventional composites because of their continuously graded structures and properties. Due to the high mathematical complexity of the initial-boundary value problems, analytical approaches for elastic analyses of FGMs are restricted to simple geometries and boundary conditions. The elastic analysis in FGM demands an accurate and… More >

Jr-Ming Miao^1,2, Fuh-Lin Lih³, Yi-Chun Liou⁴, Hsiu-Kai Chen¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 33-34, 2009, DOI:10.3970/icces.2009.012.033

Abstract To date, miniaturization of fluid handling and fluid analysis devices in the medicine engineering has been emerging in the interdisciplinary research field of micro-fluidics, as a result of miniaturization of the detective device to allow parallelization as well as to reduce analysis time and sample volume. Micro-total-analysis-system (μ -TAS) researches aimed at developing miniaturized and integrated ``lab-on-a-chip'' devices for biochemical analysis applications. Droplet-based micro-mixer is the one of the key components in the developing of μ-TAS. Numerical approach on the dynamic formation of water droplets in a T-type microchannel with a 200μm × 50μm rectangular cross section… More >

Ch.Raghuveer¹, Mohit Pant¹, I.V. Singh¹, B.K. Mishra¹, V. Bhasin², Kamal Sharma², I.A. Khan²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 23-32, 2009, DOI:10.3970/icces.2009.012.023

Abstract In this work, element free Galerkin method (EFGM) has been applied to solve solid mechanics problems containing material discontinuities. The method is based on treatment of interface conditions at the variational level. Modifications are made in the EFGM to incorporate material discontinuities, which include the variational form of the governing differential equations. Two bi-material problems i.e. beam and bar has been solved using EFGM, and a clear discontinuity in the stress field has been observed at the interface of two materials. More >

Mohit Pant¹, I. V. Singh¹, B. K. Mishra¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 13-22, 2009, DOI:10.3970/icces.2009.012.013

Abstract In this work, element free Galerkin method (EFGM) has been used to obtain the solution of centre crack problem under thermo-mechanical loads as it provides a versatile technique to model static as well as moving crack problems without any requirement of re-meshing. Diffraction criterion has been used to model crack geometry. The effect of crack orientation of centre crack has been studied under both mechanical and equivalent thermal loading under plane stress conditions. The values of mode-I and mode-II stress intensity factors have been evaluated by the interaction integral approach. More >

Eun A Hwang¹, Haeng-Ki Lee¹, Jong Won Kwark², Jung Woo Lee²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 11-12, 2009, DOI:10.3970/icces.2009.012.011

Abstract Concrete structures such as concrete safety barriers are often subjected to direct impact loads mainly due to vehicle crash impact. In this case, the impact resistance is one of the most critical characteristic of concrete used in such structures. The present study aims to characterize the impact resistance of lightweight aggregate cellular concrete (LACC), which will be used in concrete barriers. Impact tests on LACC specimens were carried out based on the repeated drop-weight impact test guideline recommend by ACI committee 544. Impact resistance and compressive strength of the LACC specimens were characterized and the More >

S.S. Kim, S.M. Chang¹, H.S. Jeong

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 9-10, 2009, DOI:10.3970/icces.2009.012.009

Abstract In this paper, the three-dimensional model of a servo valve working in the fuel supply system of auxiliary power unit (APU) for the gas turbine engine is studied with numerical simulation of multiphysical system. The physics of electromagnetics, structural dynamics, and fluid dynamics are expressed in the form of independent system of partial differential equations, respectively. A commercial code named COMSOL is used to simulate the essential physics of the servo valve system, and the extracted data is used for the simulation of entire servo valve, which is coupled with torque motor, bushing tube, and More >