Open Access

ABSTRACT

Milazzo A.¹, aimo A.¹, Benedetti I.¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 151-156, 2008, DOI:10.3970/icces.2008.006.151
Abstract The effect of the finite stiffness bonding between the piezoelectric plies of bimorph devices has been investigated. A boundary integral formulation for piezoelasticity, based on a multidomain technique with imperfect interface conditions, has been developed. The imperfect interface conditions between the piezoelectric layers are described in terms of linear relations between the interface tractions, in normal and tangential directions, and the respective discontinuity in displacements. Continuity of the electric potential at the interface is also assumed and an iterative procedure is implemented to avoid interface interference. Numerical analysis has been performed on bimorph configurations with More >

View

980

Download

758

Open Access

ABSTRACT

Mijia Yang¹, Qiao Pizhong²
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 157-168, 2008, DOI:10.3970/icces.2008.006.157
Abstract A new fatigue model suitable for polymer matrix composites is proposed, based on dimensional analysis of testing and material variables involved in a fatigue test. The new model has a good physical and theoretical foundation based on progressive damage, and unifies all the material and testing parameters into one general equation. Especially, the model can be simplified to the Goodman relation or Gerber relation when capturing the effect of mean stresses. The model suggested can be used to substitute the classical S-N curves and reduce the testing number by 50{\%} required by ASTM standards. A More >

View

1036

Download

821

Open Access

ABSTRACT

S. Kobayashi¹, J. Ji¹, H. Morikawa¹, D. Tang², D. N. Ku³
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 169-174, 2008, DOI:10.3970/icces.2008.006.169
Abstract The increase of the blood velocity in the distal side of the stenosis causes negative transmural pressure, and atheroscrerotic plaque is compressed, furthermore, the stenosis may cause the collpase which leads the rupture of the plaque. The resultant compression may be important in the development of atherosclerotic plaque fracture and subsequent thrombosis or distal embolization. We have developed stenosis models made of polyvinyl alcohol hydrogel, which closely approximate an arterial disease situation, and performed pulsatile flow experiments. Valsalva's maneuver and cough cause a sharp rise in jugular venous pressure to greater than 50 mmHg. Such More >

View

1145

Download

737

Open Access

ABSTRACT

J. Useche¹, P. Sollero², E.L. Albuquerque², L. Palermo³
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 175-182, 2008, DOI:10.3970/icces.2008.006.175
Abstract The computational fracture analysis of cracked thick plates repaired with adhesively bonded composite patches using a boundary element formulation is presented. The shear deformable cracked isotropic plate was modeled using the Reissner's plate theory. In order to model the repair, a three parameter boundary element formulation, based on Kirchhoff's theory for symmetric layered composite plates was established. Interaction forces and moments between the cracked plate and the composite repair were modeled as distributed loads. Coupling equations, based on kinematic compatibility and equilibrium considerations for the adhesive layer, were established. In-plane shear-deformable model with transversal stiffness More >

View

988

Download

766

Open Access

ABSTRACT

A.Iwasaki¹, K.Yuguchi², A.Todoroki³, Y.Shimamura⁴
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 183-188, 2008, DOI:10.3970/icces.2008.006.183
Abstract The present study is about study on the diagnostic accuracy of the unsupervised damage diagnosis method named SI-F method. For the health monitoring of existing structures, modeling of entire structure or obtaining data sets after creating damage for training is almost impossible. This raises significant demand for development of a low-cost diagnostic method that does not require modeling of entire structure or data on damaged structure. Therefore, the present study proposes a low-cost unsupervised statistical diagnostic method for structural damage detection. The proposed method statistically diagnoses structural condition by means of investigating the change of… More >

View

1106

Download

780

Open Access

ABSTRACT

Y. Shimamura¹, Y. Shibata², K. Tohgo³, H. Araki⁴
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 189-194, 2008, DOI:10.3970/icces.2008.006.189
Abstract Polylactic acid (PLA) is a biodegradable plastic made from lactic acid, and can be produced by renewable raw materials. The mechanical properties of PLA are, however, not sufficient for structural materials. In our study, carbon nanofiber reinforced PLA was fabricated to overcome the deficiency of PLA and the mechanical properties were measured at room and elevated temperatures. Vapor grown carbon fiber (VGCF) was used for reinforcement. Three point bending specimens were fabricated by using injection molding, and then bending stiffness, bending strength and fracture toughness were measured for amorphous and crystallized specimens. As a result, More >

View

1010

Download

886

Open Access

ABSTRACT

I. Yoshida ¹
The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 195-200, 2008, DOI:10.3970/icces.2008.006.195
Abstract A priori information is discussed in order to overcome the ill-posedness of damage detection. We compared Gauss and Laplace distributions to express the uncertainties of a priori information. Uncertainty level of a priori and observation information is related to the balance of a priori and observation terms in the objective function. Maximum likelihood method is used to determine the balance adaptively. The method is examined through numerical simulations of identification problem to detect damage of a bridge based on coupling vibration with moving vehicles. More >

View

1152

Download

843