scholarly journals Crack Length Dependency of Intralaminar and Interlaminar Crack Growth Properties for CF/Epoxy Laminate under Mode I Static and Fatigue Loadings

2016 ◽  
Vol 42 (1) ◽  
pp. 34-45
Author(s):  
Narumichi SATO ◽  
Masaki HOJO ◽  
Masaaki NISHIKAWA
Keyword(s):  
Crack Length ◽  
Crack Growth ◽  
Mode I ◽  
Growth Properties ◽  
Interlaminar Crack

Interlaminar Crack Growth Resistances of Various Ceramic Matrix Composites in Mode I and Mode II Loading

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Sung R. Choi ◽  
Robert W. Kowalik
Keyword(s):  
Crack Growth ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Mode I ◽  
Mode Ii ◽  
Crack Plane ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Interlaminar Crack ◽  
Sic Composites

Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade melt-infiltrated SiC∕SiC composites. Modes I and II crack growth resistances, GI and GII, were determined at ambient temperature using double cantilever beam and end notched flexure methods, respectively. The CMCs exhibited GI=200–500J∕m2 and GII=200–900J∕m2. All the composites (except for one SiC/CAS composite) showed a rising R-curve behavior either in mode I or in mode II, presumably attributed to fiber bridging (in modes I and II) and frictional constraint (mode II) in the wake region of a propagating crack. A glass fiber-reinforced epoxy polymer matrix composite showed typically two to three times greater GI and eight times greater GII, compared to the CMCs. An experimental error analysis regarding the effect of the off-the-center of a crack plane on GI and GII was also made.

Interlaminar Crack Growth Resistances of Various Ceramic Matrix Composites in Mode I and Mode II Loading

2007 ◽  
Author(s):  
Sung R. Choi ◽  
Robert W. Kowalik
Keyword(s):  
Crack Growth ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Mode I ◽  
Mode Ii ◽  
Crack Plane ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Interlaminar Crack ◽  
Sic Composites

Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade MI SiC/SiC composites. Modes I and II crack growth resistances, GI and GII, were determined at ambient temperature using double cantilever beam (DCB) and end notched flexure (ENF) methods, respectively. The CMCs exhibited GI = 200–500 J/m2 and GII = 200–900 J/m2. All the composites (except for one SiC/CAS composite) showed rising R-curve behavior either in mode I or in mode II, presumably attributed to fiber bridging (in modes I and II) and frictional constraint (mode II) in the wake region of a propagating crack. A glass fiber-reinforced epoxy polymer matrix composite, used as comparison, showed typically 2-3 and 8 times greater in GI and GII, respectively, compared to the CMCs. Experimental error analysis regarding the effect of the off-the-center of a crack plane on GI and GII was also made.

Shear-Type Fatigue Crack Growth in SAE52100 Steel

2007 ◽  
Vol 353-358 ◽  
pp. 287-290
Author(s):  
Daisuke Cho ◽  
Hisao Matsunaga ◽  
Masahiro Endo
Keyword(s):  
Fatigue Crack ◽  
Crack Length ◽  
Crack Growth ◽  
Compressive Stress ◽  
Axial Direction ◽  
Specimen Surface ◽  
Mode I ◽  
Crack Face ◽  
Artificial Defect ◽  
Shear Type

Shear-type fatigue crack behavior in a bearing steel, SAE52100, was investigated in a biaxial fatigue testing machine using cylindrical specimens. Either of the following two types of artificial defect with the total length of 400 ~ 440 %m and the depth of 200 ~ 300 %m was introduced into the specimen surfaces: (a) a semi-elliptical pre-crack emanating from 2 adjacent holes by a tension-compression loading, (b) 3 adjacent holes oriented in the axial direction which had slits made by the focused ion beam technique at the both ends. Fully reversed torsion with a shear stress amplitude at specimen surface, τa = ~ 600 MPa, was applied to the specimens under the static axial compressive stress σm = −1000 ~ −1200 MPa. In case of the defect (a), a shear-type crack propagated from the pre-crack in direction perpendicular to the specimen axis. At the specimen surface, the shear-type crack periodically branched from the crack tip and propagated 5~10 %m in Mode I directions. The shear-type crack growth was decelerated with an increase in the crack length and finally stopped at N ≅ 7.5×106 cycles and 2a ≅ 600 %m. On the other hand, in case of the defect (b), the shear-type crack propagated in axial direction, and the crack growth was accelerated with an increase in the crack length. In addition, the threshold stress in case without the compressive stress on crack-face was determined by a τa-decreasing test. The results revealed that the shear-type crack growth was strongly influenced by the crack-face friction and the existence of the Mode I blanched cracks.

scholarly journals Mode I interlaminar crack length prediction by the resistance signal of the integrated MWCNT sensor in WGF/epoxy composites during DCB test

2020 ◽  
Vol 9 (3) ◽  
pp. 5922-5933 ◽  
Author(s):  
Yun Wan ◽  
Hailong Yang ◽  
Zhenhua Tian ◽  
Bin Yang ◽  
Guang Xian ◽  
...  
Keyword(s):  
Crack Length ◽  
Epoxy Composites ◽  
Mode I ◽  
Interlaminar Crack
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