• 기계와재료
• /
• v.7 no.2 s.24
• /
• pp.58-67
• /
• 1995

• 기계와재료
• /
• v.4 no.2 s.12
• /
• pp.78-92
• /
• 1992

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.11a
• /
• pp.230-230
• /
• 2009

가스절연 개폐장치 (Gas Insulated Switchgear : GIS)의 고체 스페이서에 경사 기능성 재료 (Functionally Graded Material : FGM)가 적용될 때, 절연성능이 크게 향상된다. 본 논문에서는 FGM 스페이서가 적용된 GIS의 전극 및 스페이서의 형상을 변경하여 최대전계를 완화시켰다. 이를 위해 완전요인실험 (Full Factorial Design : FFD)과 결합된 반응표면법 (Response Surface Methodology : RSM)의 최적화기법을 이용하여, 전극 및 스페이서의 최적 형상을 설계하였다.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2001.05a
• /
• pp.163-163
• /
• 2001

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2000.11a
• /
• pp.145-145
• /
• 2000

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2000.11a
• /
• pp.160-160
• /
• 2000

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1996.05a
• /
• pp.52-52
• /
• 1996

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.2
• /
• pp.193-203
• /
• 2014

Temperature-dependent stress analysis and heat transfer analysis of a rotating gas turbine blade made of functionally graded materials (FGMs) are presented considering turbine operating temperature and ceramic particle size. The material properties of functionally graded materials are assumed to vary continuously and smoothly across the thickness of the thin-walled blade. For obtaining system stiffness reflecting these characteristics, the one-dimensional heat transfer equation is applied along the thickness of the thin-walled blade for determining the temperature distribution. Using the results of the temperature analysis, the equations of motion of a rotating blade are derived with hybrid deformation variable modeling method along with the Rayleigh-Ritz assumed mode methods. The validity of the derived rotating blade model is evaluated by comparing its transient responses and temperature distribution with the results obtained using a commercial finite element code. The maximum tensile stress with operating speed and gradient index are obtained. Furthermore, the gradient index that minimizes blade temperature was investigated.

• Composites Research
• /
• v.16 no.5
• /
• pp.21-27
• /
• 2003

Using the theory of linear piezoelectricity, the dynamic response of a central crack in a functionally graded piezoelectric ceramic under anti-plane shear impact is analyzed. We assume that the properties of the functionally graded piezoelectric material vary continuously along the thickness. By using the Laplace and Fourier transform, the problem is reduced to two pairs of dual integral equations and then into Fredholm integral equations of the second kind. Numerical values on the dynamic stress intensity factors are presented to show the dependence of the gradient of material properties and electric loading.

• Korean Journal of Materials Research
• /
• v.3 no.3
• /
• pp.261-271
• /
• 1993

Functionally Gradient Materials(FGM) of 4.5Pb($Ni_{1/3}Nb_{2/3})O_3$-55PZT and PLZT(lO/70 /30, 11/60/40) were prepared. Its dielectric and piezoelectric strain properties were investigated. The FGM were pressed into A/B/ A configuration using two kinds of films, one layer(A) was eliminated from FGM by polishing after sintering at $l250^{\circ}C$, 2 hrs. The acrylic binder system was successfully applied for crack free film through doctor blade method. The thickness of gradent layer in FGM was about 30${\mu}$m. Dielectric properties of FGM show the average value of each side layer. The strain-electric field characteristics of FGM were significantly improved comparison with the other single compositions. The prepared FGM piezoelectric actuator shows about 3${\mu}$m/IOOV displacement.