Fig. 1 Schematic representation of damage process in woven-fabric composites during fatigue [ 2 ]: ( a ) no damage, ( b ) transverse Matrix cracking, ( c ) fatigue life, ( d ) delamination at crossover points, and ( e ) fiber fracture and fiber splitting in warp bundles Schematic representation ... More

Fig. 2 Finite element model details: ( a ) global FE model, ( b ) fractography of the Teflon insert, and ( c ) FE mesh refinement around the flaw Finite element model details: (a) global FE model, (b) fractography of the Teflon insert, and (c) FE mesh refinement around the flaw More

Fig. 3 Stress distribution calculated along the edges of the flaw: ( a ) schematic details of the specimen and location of the flaw inside the composite, ( b ) normal stress S z , and ( c ) shear stress S xz Stress distribution calculated along the edges of the flaw: (a) schematic detai... More

Fig. 4 Normal and shear stresses through the thickness of the specimen: ( a ) bottom side, ( b ) left side, ( c ) top side, and ( d ) right side of the inserted flaw Normal and shear stresses through the thickness of the specimen: (a) bottom side, (b) left side, (c) top side, and (d) right side ... More

Fig. 5 Specimen geometry and definition of the inspection zone Specimen geometry and definition of the inspection zone More

Fig. 6 Experimental testing and monitoring setup Experimental testing and monitoring setup More

Fig. 7 Principle of planar localization algorithm using four AE sensors Principle of planar localization algorithm using four AE sensors More

Fig. 8 Air-coupled ultrasonics acquisition chain Air-coupled ultrasonics acquisition chain More

Fig. 9 Typical failure modes observed for no-flaw specimen NFS1 (top) and with-flaw specimen WFS1 (bottom) Typical failure modes observed for no-flaw specimen NFS1 (top) and with-flaw specimen WFS1 (bottom) More

Fig. 10 ( a ) Ultrasound testing C-scan result and ( b ) through the thickness X-ray analysis results (a) Ultrasound testing C-scan result and (b) through the thickness X-ray analysis results More

Fig. 11 ( a ) Cumulative counts for NFS and ( b ) cumulative counts for WFS (a) Cumulative counts for NFS and (b) cumulative counts for WFS More

Fig. 12 Acoustic signals features: ( a ) peak frequency versus duration and ( b ) duration versus lifespan Acoustic signals features: (a) peak frequency versus duration and (b) duration versus lifespan More

Fig. 13 Location of AE events for NFS1 (top) and WFS1 (bottom) over: ( a ) 20%, ( b ) 50%, and ( c ) 100% of the fatigue life Location of AE events for NFS1 (top) and WFS1 (bottom) over: (a) 20%, (b) 50%, and (c) 100% of the fatigue life More

Fig. 14 Normalized stiffness degradation of ( a ) NFS and ( b ) WFS, over the normalized fatigue life measured using DIC Normalized stiffness degradation of (a) NFS and (b) WFS, over the normalized fatigue life measured using DIC More

Fig. 15 Evolution of the longitudinal strain field over the normalized fatigue life Evolution of the longitudinal strain field over the normalized fatigue life More

Fig. 16 ( a ) Comparison of the average longitudinal strain field between global and flaw zone over the normalized fatigue life and ( b ) Normalized stiffness degradation on flaw area over normalized fatigue life (a) Comparison of the average longitudinal strain field between global and flaw zon... More

Fig. 17 Out-of-plane displacement field Out-of-plane displacement field More

Fig. 18 Wave velocity decay over normalized fatigue life for ( a ) NFS and ( b ) WFS Wave velocity decay over normalized fatigue life for (a) NFS and (b) WFS More

Fig. 1 Ti–6Al–4V specimens: ( a ) baseplate with as-built deposition, ( b ) baseplate with glazed deposition, and ( c ) baseplate. One 76 mm × 38 mm section of each deposition is end-milled and polished. The glazed surface has higher reflectivity than the as-built surface. Ti–6Al–4V specimens: (... More

Fig. 2 Three-dimensional and 1D surface profiles for Ti–6Al–4V: ( a ) polished baseplate, ( b ) as-built specimen, and ( c ) glazed specimen. Note that the z -axis scales vary. Three-dimensional and 1D surface profiles for Ti–6Al–4V: (a) polished baseplate, (b) as-built specimen, and (c) glazed... More