scholarly journals Effect of fiber bridging in composites healing

2021 ◽  
Author(s):  
M. Elhadary ◽  
A. Hamdy ◽  
W. Shaker
Keyword(s):  
Fiber Bridging

Study on Conductive Mechanism of Carbon Fiber Filled Cement-Based Composites

2011 ◽  
Vol 415-417 ◽  
pp. 1435-1438
Author(s):  
Xue Li Nan ◽  
Xiao Min Li
Keyword(s):  
Electrical Resistivity ◽  
Carbon Fiber ◽  
Cement Paste ◽  
Ionic Conduction ◽  
Strong Electrolyte ◽  
Pull Out ◽  
Fiber Bridging ◽  
Interface Contact ◽  
Conductive Mechanism ◽  
Conductive Properties

In order to investigate conductive mechanism of carbon fiber filled cement-based composites, the conductive properties of cement paste, carbon fiber filled cement-based composites containing different contents of carbon fibers or aggregates were studied. Experimental results indicate that the electrical resistance of the plain cement paste obviously increases with hydration time, which results from the ionic conduction in strong electrolyte solution. The electrical resistivity of the carbon fiber filled cement-based composites decreases with the increase of fiber content. Both contacting conduction and ionic conduction are in charge of the electrical conduction in these composites. The electrical resistivity of the carbon fiber filled cement-based composites decreases under compression, which is due to the improvement of interface contact between matrix and fibers and the increase of fiber bridging probability. The fiber pull-out and breaking under tension lead to an increase in electrical resistivity of these composites. Aggregates block fiber dispersion and contact. This causes an increase in electrical resistivity of the composites.

A fiber bridging model for fatigue delamination in composite materials

2004 ◽  
Vol 52 (19) ◽  
pp. 5493-5502 ◽  
Author(s):  
Jeremy R. Gregory ◽  
S. Mark Spearing
Keyword(s):  
Composite Materials ◽  
Fiber Bridging ◽  
Bridging Model

Crack Resistance Function Analysis of Flexible Short Fiber in Asphalt

2011 ◽  
Vol 243-249 ◽  
pp. 4182-4187
Author(s):  
Zhi Yong Ding ◽  
Jing Liang Dai ◽  
Bo Peng
Keyword(s):  
Mechanical Model ◽  
Function Analysis ◽  
Short Fiber ◽  
Calculation Model ◽  
Tensile Failure ◽  
Spherical Coordinates ◽  
Short Fibers ◽  
Flexible Fiber ◽  
Fiber Bridging ◽  
Resistance Function

after reasonably analyzing characteristics of flexible fiber reinforcement fragile material, the mechanical model of individual fiber is established while being pulled out from asphalt; the spherical coordinates is adopted to establish the calculation model for short fiber bridging stress evenly distributed in space to calculate the value of bridging stress generated by short fibers while asphalt is breaking; the fiber asphalt sample in big size is adopted to perform low temperature tensile failure test to practically measure bridging stress of short fiber; fit the calculated value and measured value of bridging stress by adjusting parameters in the calculation model to check the rationality of fiber bridging stress in calculation method and model.

Plain para-aramid/phenolic multiwall carbon nanotubes prepreg/multistiched preform composites: Experimental characterization of mode-I toughness

2018 ◽  
Vol 53 (13) ◽  
pp. 1847-1864 ◽  
Author(s):  
K Bilisik ◽  
E Sapanci
Keyword(s):  
Fracture Toughness ◽  
Multiwall Carbon Nanotubes ◽  
Beam Theory ◽  
Mode I ◽  
Multiwall Carbon Nanotube ◽  
Axial Filament ◽  
Pull Out ◽  
Fiber Bridging ◽  
Nanotube Composites ◽  
Multiwall Carbon

The fracture toughness (mode-I) properties of nanostitched para-aramid/phenolic multiwall carbon nanotube prepreg composites were investigated. The fracture toughness (GIC) of the stitching and nanostitched composites showed 42-fold and 41-fold (beam theory), 18-fold and 21-fold (modified beam theory) increase compared to the control, respectively. The prepreg para-aramid stitching yarn and nanostitched yarn were dominant parameters. The toughness resistance to arrest crack growth in the nanostitched composite was primarily due to nanostitching fiber bridging and pull-out, and was secondarily due to nanotubes and biaxial fiber bridging and pull-out. The failed surfaces of the nanostitched and stitching composites had tensile filament failures in the aramid stitching fibers where filament/matrix/nanotube debonding and axial filament fibrillar splitting were found. The results indicated that stitching yarn and the nanotubes arrested the crack propagation. Therefore, the nanostitched and stitched para-aramid/phenolic composites displayed a better damage resistance performance compared to those of the control or nanotube composites.

Effect of Cellulose Functionalization on Thermal and Mechanical Properties of Epoxy Resin

2017 ◽  
Vol 757 ◽  
pp. 62-67 ◽  
Author(s):  
Kritsanachai Leelachai ◽  
Supissara Ruksanak ◽  
Tarakol Hongkeab ◽  
Supakeat Kambutong ◽  
Raymond A. Pearson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Diglycidyl Ether ◽  
Cellulose Content ◽  
Thermal And Mechanical Properties ◽  
Chemical Surface ◽  
Pull Out ◽  
Fiber Bridging ◽  
Surface Modified ◽  
Modified Epoxy

In this study, diglycidyl ether of bisphenol A (DGEBA) cured cycloaliphatic polyamine was modified with functionalized celluloses for improved thermal and mechanical properties. Three different types of surface-modified cellulose, polyacrylamide-g-cellulose (PGC), aminopropoxysilane-g-cellulose (SGC), and carboxymethyl cellulose (CMC), were investigated and used as reinforcing agents in epoxy resins. The storage modulus of these modified epoxy systems was found to significantly increase with addition of cellulose fillers (up to 1 wt. % cellulose content). An improved fracture toughness (KIC) was also observed with increasing cellulose loading content with PGC and SGC. Among the surface-modified celluloses, epoxy modified with SGC was found to have the highest fracture toughness followed by PGC and CMC at 1.0 wt.% cellulose addition due to the chemical surface compatibility. The toughening mechanisms of the cellulose/epoxy composites, measured by scanning electron microscopy (SEM), revealed that fiber-debonding, fiber-bridging, and fiber-pull out were responsible for increased toughness.

Effect of multiple matrix cracking on crack bridging of fiber reinforced engineered cementitious composite

2020 ◽  
Vol 54 (26) ◽  
pp. 3949-3965 ◽  
Author(s):  
Xuan Zheng ◽  
Jun Zhang ◽  
Zhenbo Wang
Keyword(s):  
Tensile Test ◽  
Crack Spacing ◽  
Matrix Cracking ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Crack Bridging ◽  
Engineered Cementitious Composite ◽  
Fiber Bridging

In the present paper, a modified micromechanics based model that describes the crack bridging stress in randomly oriented discontinuous fiber reinforced engineered cementitious composite is developed. In the model, effect of multiple matrix cracking on fiber embedded length, which in turn influencing fiber bridging in the composite, is taken into consideration. First, crack spacing of high strength-low shrinkage engineered cementitious composite was experimentally determined by photographing the specimen surface at some given loading points during uniaxial tensile test. The diagram of average cracking spacing and loading time of each composite is obtained based on above data. Then, fiber bridging model is modified by introducing a revised fiber embedment length as a function of crack spacing. The model is verified with uniaxial tensile test on both tensile strength and crack opening. Good agreement between model and test results is obtained. The modified model can be used in design and prediction of tensile properties of fiber reinforced cementitious composites with characteristics of multiple matrix cracking.

scholarly journals Effects of Hybridized Synthetic Fibers on the Shear Properties of Cement Composites

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5055
Author(s):  
S.M. Iqbal S. Zainal ◽  
Farzad Hejazi ◽  
Farah N. A. Abd. Aziz ◽  
Mohd Saleh Jaafar
Keyword(s):  
Mechanical Properties ◽  
Synergistic Effects ◽  
Reinforced Concrete Structures ◽  
Cement Composites ◽  
Direct Shear ◽  
Hybrid Fiber ◽  
Conventional Concrete ◽  
Synthetic Fibers ◽  
Fiber Bridging ◽  
Shear Energy

The use of fibers in cementitious composites yields numerous benefits due to their fiber-bridging capabilities in resisting cracks. Therefore, this study aimed to improve the shear-resisting capabilities of conventional concrete through the hybridization of multiple synthetic fibers, specifically on reinforced concrete structures in seismic-prone regions. For this study, 16 hybrid fiber-reinforced concretes (HyFRC) were developed from the different combinations of Ferro macro-synthetic fibers with the Ultra-Net, Super-Net, Econo-Net, and Nylo-Mono microfibers. These hybrids were tested under direct shear, resulting in improved shear strength of controlled specimens by Ferro-Ultra (32%), Ferro-Super (24%), Ferro-Econo (44%), and Ferro-Nylo (24%). Shear energy was further assessed to comprehend the effectiveness of the fiber interactions according to the mechanical properties, dosage, bonding power, manufactured material, and form of fibers. Conclusively, all fiber combinations used in this study produced positive synergistic effects under direct shear at large crack deformations.

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