• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.671-674
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• 2001

The dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system is utilized to record the dynamically propagating behavior of the interface crack. This paper investigates the effects of the stiffness of interface defect(exist along the path of the crack propagation) on the dynamic interface crack propagation behavior by comparing the experimental isochromatic fringes to the theoretical stress fields.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.429-432
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• 2000

The dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system is utilized to record the dynamically propagating behavior of the interface crack. This paper investigates the effects of the hole (existed along the path of the crack propagation) shape on the dynamic interface crack propagation behavior by comparing the experimental isochromatic fringes to the theoretical stress fields.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.837-840
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• 2002

An analysis method for rubber toughened PVC is suggested to evaluate critical dynamic strain energy release rates($G_c$) from the Charpy impact energy measurements. An instrumented Charpy impact tester was used to extract ancillary information concerning fracture parameters in addition to total fracture energies and maximum critical loads. The dynamic stress intensity factor $K_{Id}$ was computed for varying amounts of rubber contents from the obtained maximum critical loads and also toughening effects were investigated as well. The fracture surfaces produced under low velocity impact fur PVC/MBS composites were investigated by SEM. The results show that MBS rubber is very effective reinforcement material for toughening PVC.C.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.219-231
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• 2004

The Charpy and Izod impact tests are the most prevalent techniques used to characterize the effects of high impulse loads on polymeric materials. An analysis method for rubber toughened PVC is suggested to evaluated critical dynamic strain energy release rates(G$_c$) from the Charpy impact tester was used to extract ancillary information concerning fracture parameters in additional to total fracture energies and maximum critical loads. The dynamic stress intensity factor KID was computed for varying amounts of rubber contents from the obtain maximum critical loads and also toughening effects were investigated as well. The fracture surfaces produced under low velocity impact for PVC/MBS composites were investigated by SEM. The results show that MBS rubber is very effective reinforcement material for toughening PVC.

• Journal of Mechanical Science and Technology
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• v.18 no.9
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• pp.1582-1589
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• 2004

The dynamic response of an eccentric Griffith crack in functionally graded piezoelectric ceramic strip under anti-plane shear impact loading is ana lysed using integral transform method. Laplace transform and Fourier transform are used to reduce the problem to two pairs of dual integral equations, which are then expressed to Fredholm integral equations of the second kind. We assume that the properties of the functionally graded piezoelectric material vary continuously along the thickness. The impermeable crack boundary condition is adopted. Numerical values on the dynamic stress intensity factors are presented for the functionally graded piezoelectric material to show the dependence of the gradient of material properties and electric loadings.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.2
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• pp.54-61
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• 1998

This paper examines the crack growth behavior of 7075-T651 aluminum alloy for small tensile overload under high-low block loading condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure are investigated by compliance method. The applied initial stress ratios are R=-0.5 R=0.0 and R=0.25 Crack length, effective stress intensity factor range, ratio of effective stress intensity factor range and crack growth rate etc, are inspected with fracture mechanics estimate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.434-442
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• 2001

When the interfacial crack of two dissimilar isotropic bi-materials is propagated with constant velocity along the interface, stress and displacement components are derived in this research. The dynamic photoelastic experimental hybrid method for bimaterial is introduced. It is assured that stress components and dynamic photoelastic hybrid method developed in this research are valid. Separating method of stress component is introduced from only dynamic photoelastic fringe patterns. Crack propagating velocity of interfacial crack is 80∼85% (in case of aluminum, 24.3∼25.9%) of Rayleigh wave velocity of epoxy resin. The near-field stress components of crack-tip are similar with those of pure isotropic material under static or dynamic loading, but very near-field stress components of crack-tip are different from those.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1217-1222
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• 2002

The dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system is utilized to record the dynamically propagating behavior of the interface crack. This paper investigates the effects of the hole (existed along the path of the crack propagation) shape on the dynamic interface crack propagation behavior by comparing the experimental isochromatic fringes to the theoretical stress fields.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1055-1063
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• 2001

When the interfacial crack of isotropic/orthotropic bi-materials is propagated with constant velocity along the interface, stress and displacement components are derived in this research. The dynamic photoelastic experimental hybrid method for the bimaterial is introduced. It is assured that stress components and dynamic photoelastic hybrid developed in this research are valid. Separating method of stress components is introduced from only dynamic photoelastic fringe patterns. Crack propagating velocity of interfacial crack is 69∼71% of Rayleigh wave velocity of epoxy resin. The near-field stress components of bonded interface of bimaterial are similar with those of pure isotopic material and two dissimilar isotropic bimaterials under static or dynamic loading, but very near-field stress components of bonded interface of bimaterial are different from those.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.127-131
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• 2000

The dynamic photoelasticity with the aid of Cranz-Shardin type high speed camera system is utilized to record the dynamically propagating behavior of an interface crack. This paper investigates determined the effects of the hole (existed on the path of the crack propagation) on the crack propagation behavior by comparing the experiment isochromatic fringes to the theoretical stress fields.