Fig. 1 Joining of advanced materials for aircrafts=2,22,1

Fig. 2 Repairing an aircraft wing with composite=3,23,1

Fig. 3／13 History of material development=4,24,1

Fig. 4 Repairing of the hip joint with advanced materials=5,25,1

Fig. 1.1 Strength of carbon fiber epoxy composite (AS／3501-5) with respect to:(a) Temperature;(b) Moisture (Browning,1972)=17,37,1

Fig. 1.2 Transverse stress-strain curves of carbon fiber epoxy composites (AS／3501-5) at different temperatures and moisture contents (Browning et al.,1977)=18,38,1

Fig. 1.3 Variation of the tensile strength of (±45˚) laminates with absorbed moisture,measured at various temperatures (Joshi,1983)=19,39,1

Fig. 1.4 Effect of temperature on interfacial shear strength values in carbon fiber epoxy composite ( ■ ) and surface treated carbon fiber epoxy composite ( ●) and on the matrix shear strength ( ▲ ) (Detassis et al.,1994)=20,40,1

Fig. 1.5 Flexural modulus vs. temperature for 'dry' and humidity conditioned composites of AS-4 fiber in epoxy matrix which is:(a) 3501-5A;(b) X4502;(c) 2220-3 (Boll et al.,1985)=21,41,2

Fig. 1.6 Flextural modulus vs. temperature for 'dry' and humidity conditioned composites of AS-4 fiber in matrix which is:(a) 3501-6;(b) 2203-3 with a glass (104 type) skrim cloth (Boll et al.,1985)=23,43,1

Fig. 1.7 Flexural stress evolution as a function of flexural strain of the glass fiber／polypropylene composite(solid line) and the glass fiber／polyester composite (dashed line) at:(a) -40 ℃;(b)23 ℃;(c)50 ℃ (Bureau and Denault,2004)=24,44,2

Fig. 1.8 Maximum flexural stress plotted against number of cycles to failure for the glass fiber／polypropylene composite(solid line) and the glass fiber／polyester composite(dashed line) at:(a) -40 ℃;(b) 23 ℃;(c) 50 ℃ (Bureau and Denault,2004)=26,46,2

Fig. 1.9 Fatigue S／N curves for unidirectional E-glass fiber reinforced phenolic composites with R＝0,frequency 1.5. ㎐,V＝0.45,fiber treatment S2 and temperature 20 ℃,100 ℃,200 ℃ (Branco et al.,1994)=28,48,1

Fig. 1.10 Tensile strength of laminate of carbon fiber epoxy composite (CF／EP),Surface treated carbon fiber epoxy composite (CF／EPmod),and carbon fiber peek composite (CF／PEEK):(a) 0˚laminate;(b) 90˚laminate (Selzer and Friedrich,1996)=29,49,1

Fig. 1.11 Elongation of 0˚laminate of carbon fiber epoxy composite (CF／EP),Surface treated carbon fiber epoxy composite (CF／EPmod),and carbon fiber peek composite (CF／PEEK):(a) 0˚laminate;(b) 90˚laminate (R. Selzer and K. Friedrich 1996)=30,50,1

Fig. 1.12 Compression strength of 0˚laminate of carbon fiber epoxy composite (CF／EP),Surface treated carbon fiber epoxy composite (CF／EPmod),and carbon fiber peek composite (CF／PEEK):(a) 0˚laminate;(b) 90˚laminate (R. Selzer and K. Friedrich 1996)=31,51,1

Fig. 1.13 Compression modulus of 0˚laminate of carbon fiber epoxy composite (CF／EP),Surface treated carbon fiber epoxy composite (CF／EPmod),and carbon fiber peek composite (CF／PEEK):(a) 0˚laminate,(b) 90˚laminate (Selzer and Friedrich,1996)=32,52,1

Fig. 1.14 Fatigue behavior of materials of carbon fiber epoxy composite (CF／EP),Surface treated carbon fiber epoxy composite (CF／EPmod),and carbon fiber peek composite (CF／PEEK),laved up [0,±45,90]2s(이미지참조):(a) dry materials,(b) fully saturated m=33,53,1

Fig. 1.15 S-N curves of dry and wet (50 days,95% relative humidity,60℃) specimens of graphite fibre／cyanate ester resin composite in log-log scale (Holl and Lee,1996)=34,54,1

Fig. 2.1 Configuration of the tensile test specimen=45,65,1

Fig. 2.2 Tensile modulus,strength and failure strain of epoxies versus experimental temperature:(a) Tensile modulus;(b) Tensile strength;(c) Tensile failure strain=46,66,2

Fig. 2.3 Configuration of the tensile test specimen=48,68,1

Fig. 2.4 Tensile modulus and tensile strength of the epoxy versus C／C(이미지참조) in the water chamber at 80℃ (IPCO 9923)=49,69,1

Fig. 2.5 SEM photograph of fillers:(a) Alumina;(b) E glass=50,70,1

Fig. 2.6 Tensile modulus and strength of IPCO 9923 epoxy including fillers versus environmental temperature:(a) Tensile modulus;(b) Tensile strength=51,71,1

Fig. 2.7 Tensile modulus and strength of DP 460 epoxy including fillers versus environmental temperature:(a) Tensile modulus;(b) Tensile strength=52,72,1

Fig. 2.8 Schematic diagram for shear test of epoxy=53,73,1

Fig. 2.9 Shear strength of epoxies versus experimental temperature=54,74,1

Fig. 2.10 DMA test result of IPCO 9923=55,75,1

Fig. 2.11 Shapes of the tubular single lap adhesive joint specimen (units in ㎜):(a) Inner adherend;(b) Outer adherend;(c) Assembled shape of the joint=58,78,1

Fig. 2.12 Average shear strength of the tubular single lap adhesive joint with respect to the alumina amount in the adhesive and the environmental temperature=56,76,1

Fig. 2.13 Shapes of the tubular single lap adhesive joint specimen (units in ㎜):(a) Inner adherend;(b) Outer adherend;(c) Assembled shape of the joint=57,77,1

Fig. 2.14 Average shear strength of the tubular single lap adhesive joint with respect to the alumina amount in the adhesive and the environmental temperature=59,79,1

Fig. 2.15 Average shear strength of the tubular single lap adhesive joint with respect to the E-glass amount in the adhesive and the environmental temperature=60,80,1

Fig. 2.16 Failure shapes of the 10% alumina filled adhesive layer after the shear test of tubular single lap adhesive joint specimen:(a) Adhesive layer on the adherend;(b) SEM photograph of the failed adhesive layer (x 2500)=61,81,1

Fig. 2.17 Failure shapes of the 10% E-glass filled adhesive layer after the shear test of tubular single lap adhesive joint specimen:(a) Adhesive layer on the adherend;(b) SEM photograph of the failed adhesive layer (x 312)=62,82,1

Fig. 2.18 Finite element model for the tubular single lap adhesive joint with 8-node axisymmetric isoparametric elements,CGAX8R (units in ㎜)=63,83,1

Fig. 2.19 Calculated maximum shear stresses in the adhesive layers of the adhesively bonded tubular single lap joints with respect to the appliedtorque and environmental temperature:(a) With IPCO 9923 epoxy adhesive;(b) With Araldite epoxy adhesive=64,84,1

Fig. 2.20 Torsional fatigue test results (S-N curves) of the adhesively bonded tubular single lap joints with respect to the environmental temperature:(a) With IPCO 9923 epoxy adhesive;(b) With Araldite epoxy adhesive=65,85,1

Fig. 2.21 A and B of torsional fatigue test results (S-N curves) of the adhesively bonded tubular single lap joints with respect to the environmental temperature:(a) With IPCO 9923 epoxy adhesive;(b) With Araldite epoxy adhesive.=66,86,1

Fig. 2.22 Configuration of the adhesively bonded joint specimen:(a) Inner adherend;(b) Outer adherend;(c) Adhesively bonded joint=67,87,1

Fig. 2.23 C／C(이미지참조) versus axial distance of adhesively bonded joint in the water chamber at 80℃ (IPCO 9923)=68,88,1

Fig. 2.24 C／C(이미지참조) of adhesively bonded joint versus exposure time in the water chamber at 80℃ (IPCO 9923)=69,89,1

Fig. 2.25 Average shear strength of the adhesively bonded tubular single lap joint under tensile load versus C／C(이미지참조) of the adhesive layer in the water chamber at 80℃ (IPCO 9923)=70,90,1

Fig. 2.26 Average shear strength of the adhesively bonded tubular single lap joint under tensile load versus C／C(이미지참조) of the adhesive layer in the water chamber at 80℃ (HYSOL EA 9460)=71,91,1

Fig. 2.27 Average shear strength of the adhesively bonded tubular single lap joint under torsional load versus C／C(이미지참조) of the adhesive layer in the water chamber at 80℃ (IPCO 9923)=72,92,1

Fig. 2.28 Average shear strength of the adhesively bonded tubular single lap joint under torsional load versus C／C(이미지참조) of the adhesive layer in the water chamber at 80℃ (HYSOL EA 9460)=73,93,1

Fig. 2.29 Fatigue life of the adhesively bonded tubular single lap joint under 3.0 ㎫ of average shear stress versus C／C(이미지참조) of the adhesive layer (IPCO 9923)=74,94,1

Fig. 3.1 Configuration of composite specimens for the resistivity measurement:(a) Through the longitudinal direction;(b) Through the transverse direction;(c) Through the thickness direction=87,107,1

Fig. 3.2 Measurement results of resistivities of carbon fiber epoxy composites (USN 150):(a) Through the longitudinal direction;(b) Through the transverse direction;(c) Through the thickness direction=88,108,1

Fig. 3.3 Composite specimens for damage monitoring by the electric resistance method=89,109,1

Fig. 3.4 Electric resistance changes of composite specimens w.r.t. crack length:(a) Between opposite electrodes;(b) Between adjacent electrodes;(c) Between diagonal electrodes=90,110,1

Fig. 3.5 Bridge circuit for modelling the internal resistance of composite specimens=91,111,1

Fig. 3.6 Composite specimens for damage monitoring by the electric potential method:(a) Dimension of composite specimens;(b) Configuration of voltage input and output=92,112,1

Fig. 3.7 Damage monitoring results of composite specimens w.r.t. electrode size by the electric potential method:(a) 2 ㎜ of electrode width;(b) 4 ㎜ of electrode width;(c) 6 ㎜ of electrode width;(d) 10 ㎜ of electrode width=93,113,2

Fig. 3.8 Damage monitoring results of composite specimens w.r.t. interval between electrodes by the electric potential method:(a) 6 ㎜ of electrode interval;(b) 10 ㎜ of electrode interval;(c) 20 ㎜ of electrode interval;(d) 30 ㎜ of electrode interval=95,115,2

Fig. 3.9 Damage monitoring results of composite specimens w.r.t. crack position by the electric potential method:(a) 25 ㎜ of crack position;(b) 50 ㎜ of crack position;(c) 75 ㎜ of crack position=97,117,2

Fig. 3.10 Damage monitoring results of composite specimens w.r.t. angle between fiber direction and crack propagation direction by the electric potential method:(a) 0˚of angle;(b) 45˚of angle;(c) 90˚of angle=99,119,2

Fig. 3.11 Comparison of damage monitoring results of composite specimens w.r.t. angle between fiber direction and crack propagation direction by the electric potential method=101,121,1

Fig. 4.1 Piezoelectricity of adhesive in the adhesive joint:(a) Adhesive joint for modeling the equivalent parallel circuit;(b) Equivalent parallel circuit of adhesive joint=115,135,1

Fig. 4.2 Schematic diagram of the interaction mechanism between the mechanical and electrical systems=116,136,1

Fig. 4.3 Depolarizing field effect in a piezoelectric body under extensional stress=117,137,1

Fig. 4.4 Stress-strain cycle for the definition of the piezoelectric constant:(a) Stress and strain;(b) Electric charge density and electric field=118,138,1

Fig. 4.5 Configuration of the d₃₃ meter and the experimental setup for measuring piezoelectric constants:(a) Conventional d₃₃ meter;(b) For measuring d₃₃;(c) For measuring d₁₃=119,139,2

Fig. 4.6 Profiles of applied shear stress and electric flux density of neat Araldite AW106／HV953 epoxy adhesive during dynamic test:(a) For measuring d₃₃;(b) For measuring d₁₃=121,141,1

Fig. 4.7 Measured electric flux density w.r.t. applied stress and Quartz filler contents:(a) For measuring d₃₃;(b) For measuring d₁₃=122,142,1

Fig. 4.8 Piezoelectric stress constants of epoxy adhesive w.r.t. Quartz filler contents=123,143,1

Fig. 4.9 Shape of the tubular single lap adhesive joint specimen:(a) Inner adherend;(b) Oouter adherend;(c) Assembled joint;(d) V-block used for concentric bonding of adhesive joints (Units in ㎜)=124,144,1

Fig. 4.10 Experimental setup for the damage monitoring of adhesive joints by the piezoelectric method and photograph of a hydraulic type Instron 8032 torque tester (Instron Co.,USA) for the torsional fatigue test of tubular single lap adhesive joints=125,145,1

Fig. 4.11 Amplitude of electric flux density of tubular single lap adhesive joints with Araldite AW106／HV953 epoxy adhesive with respect to:(a) Amplitude of the alternating shear stress (b) Amplitude of the alternating shear strain=126,146,1

Fig. 4.12 Piezoelectric stress constant of tubular single lap adhesive joints with Araldite AW106／HV953 epoxy adhesive with respect to shear mean stress=127,147,1

Fig. 4.13 (a) Amplitude of electric flux density of tubular single lap adhesive joints with Araldite AW106／HV953 epoxy adhesive with respect to tensile mean stress;(b) Slope and intersection of linear fitting curve of Fig. 4.11a=128,148,1

Fig. 4.14 Amplitude of electric flux density of tubular single lap adhesive joints with Araldite AW106／HV953 epoxy adhesive:(a) With respect to the amplitude of alternating shear stress under the same maximum shear stress:(b) Comparison of the amplitude=129,149,1

Fig. 4.15 Amplitude of electric flux density and piezoelectric stress constant of tubular single lap adhesive joints with Araldite AW106／HV953 epoxy adhesive with respect to Quartz filler contents:(a) Amplitude of electric flux density;(b) Piezoelectric=130,150,1

Fig. 4.16 Typical electric flux density during torsional fatigue test of the tubular single lap adhesive joint using the piezoelectric method:(a) Electric flux density around 100 cycles;(b) Amplitude of electric flux density obtained by connecting the pea=131,151,1

Fig. 4.17 Amplitudes of electric flux density obtained by connecting the peak values of the wholecycles with respect to the amplitude of the alternating shear stress:(a) When the amplitude of shear stress was 7.1 ㎫;(b) When the amplitude of shear stress=132,152,2

Fig. 4.18 Amplitudes of electric flux density obtained by connecting the peak values of the whole cycles with respect to the tensile mean stress when the amplitude shear stress was7.1 ㎫:(a) The tensile mean stress of 0.0 ㎫;(b) The tensile mean stress of=134,154,2

Fig. 4.19 Simplified models of the adhesive layer with an inside crack used for explaining the relation between the crack length and the measured electric charge:(a) When the crack length is relatively short at the initial stage of the fatigue test;(b) Wh=136,156,1

Fig. 4.20 Method for the prediction of the crack length and growth in the adhesive layer by the piezoelectric method=137,157,1

Fig. 4.21 (a) Finite element model for the tubular single lap adhesive joint (all dimensions in ㎜):(b) Modelling of fatigue crack propagation in the adhesive layer=138,158,1

Fig. 4.22 Distributions of shear stress,strain and electric flux density distribution in the adhesive layer of the tubular single lap adhesive joint along the axial distance x when the applied torque was 30 Nm with respect to the crack length:(a) Shear st=139,159,2

Fig. 4.23 Schematic diagram of electric charge flow in the adhesive layer with a fatigue crack=141,161,1

Fig. 4.24 Comparison between the measured (Symbols) and calculated (Lines) electric flux density changes with respect to the crack length and initial shear stress amplitude in the adhesive layer (Failure is indicated by x )=142,162,1

Fig. 4.25 Prediction of the fatigue crack length and growth with respect to fatigue cycles by the piezoelectric method:(a) Measured electric flux density during fatigue tests by the piezoelectric method:(b) Ccalculated electric flux density with respect t=143,163,2

Fig. 5.1 Main page for optimal design program of composite materials=153,173,1

Fig. 5.2 Input module of laminae of composite material=154,174,1

Fig. 5.3 Input module of staking sequence=155,175,1

Fig. 5.4 Input module of load and environment parameter for optimal design program of composite materials=156,176,1

Fig. 5.5 Text output of stress,strain and failure parameter of laminated composite materials=157,177,1

Fig. 5.6 Graphic output of stress,strain and failure parameter of laminated composite materials=158,178,1

Fig. 5.7 Diagram of output module:(a) Stress,strain of composite laminate;(b) Stress,strain around hole of composite laminate;(c) Failure analysis of composite laminate=159,179,1

Fig. 5.8 Main.or optimal design program of adhesive joint=160,180,1

Fig. 5.9 Input module of property of materials:(a) Input of property of adhesive;(b) Input of property of adherend=161,181,1

Fig. 5.10 Input module for optimal design program of tubular single lap joint:(a) Geometry of tubular single lap joint;(b) Input window of tubular single lap joint=162,182,1

Fig. 5.11 Input module for plate double lap joint:(a) Geometry of plate double lap joint;(b) Input window of plate double lap joint=163,183,1

Fig. 5.12 Input module of load and environment parameter optimal design program of adhesive joint:(a) Input of load;(b) Input of environment=164,184,1

Fig. 5.13 Output module for optimal design program of adhesive joint:(a) Text output of shear stress in adhesive layer;(b) Graphic output of shear stress in adhesive layer=165,185,1

Fig. 6.1 Shape of the tubular single lap adhesive joint specimen:(a) Inner adherend;(b) Outer adherend;(c) Assembled joint;(d) V-block used for concentric bonding of adhesive joints (Units in ㎜)=174,194,1

Fig. 6.2 Typical electric flux density during torsional fatigue test of the tubular single lap adhesive joint using the piezoelectric method:(a) Electric flux density around 100 cycles;(b) Amplitude of electric flux density obtained by connecting the peak=175,195,1

Fig. 6.3 Amplitudes of electric flux density obtained by connecting the peak values of the wholecycles with respect to the amplitude of the alternating shear stress:(a) When the amplitude of shear stress was 7.1 ㎫;(b) When the amplitude of shear stress w=176,196,2

Fig. 6.4 Amplitudes of electric flux density obtained by connecting the peak values of the whole cycles with respect to the tensile mean stress when the amplitude shear stress was7.1 ㎫:(a) The tensile mean stress of 0.0 ㎫;(b) The tensile mean stress of=178,198,2

Fig. 6.5 Noinnalized electric flux density (a*(이미지참조)) and its rate (da*(이미지참조)／dt*(이미지참조)) with respect to the noiiualized fatigue cycle (N*(이미지참조)) reproduced from Fig. 6.3:(a) Normalized electric flux density (a*(이미지참조));(b) D=180,200,1

Fig. 6.6 Noi malized electric flux density (a*(이미지참조)) and its rate (da*(이미지참조)／dt*(이미지참조)) with respect to the normalized fatigue cycle (N*(이미지참조)) reproduced from Fig. 6.4:(a) Normalized electric flux density (a*(이미지참조));(b) De=181,201,1

Fig. 6.7 Noinialized electric flux density (a*(이미지참조)) and its rate (da*(이미지참조)／dt*(이미지참조)) with respect to the fatigue life at the noiinalized fatigue cycle (N*(이미지참조)) of 0.90=182,202,1

Fig. 6.8 Relations between the noilnalized electric flux density (a*(이미지참조)) and its rate (da*(이미지참조)／dt*(이미지참조)) at the normalized fatigue cycle (N*(이미지참조)) of 0.90,0.95 and 0.99=183,203,1

Fig. 6.9 Diagnosis system for the safety evaluation of adhesive joints:(a) Configuration of system setup;(b) Photographs of constructed diagnosis system=184,204,1

Fig. 6.10 Software for diagnosis system for the safety evaluation of adhesive joints:(a) Photograph of graphic user interface of diagnosis software;(b) Diagram of calculation module for diagnosis software=185,205,1

Fig. 6.11 Diagnosis results (Normalized fatigue cycle when the diagnosis system gave the alarm,Nd*(이미지참조)) when the suggested critical normalized fatigue cycles (Nc*(이미지참조)) were 0. 90,0.95 and 0.99=186,206,1