scholarly journals Prediction of Residual Tensile Strength after Fatigue in Unidirectional Brittle Fiber-Reinforced Ceramic Composites

2011 ◽  
Vol 5 (2) ◽  
pp. 64-74 ◽  
Author(s):  
Keiji OGI
2012 ◽  
Vol 512-515 ◽  
pp. 916-919
Author(s):  
Ping Zhai ◽  
Xiao Feng Duan ◽  
Da Qian Chen ◽  
Chong Hai Wang ◽  
Fang Gao ◽  
...  

Fiber porous ceramics are the excellent candidates for a variety of applications, and thus, their research is a hotspot in recent years. In this study, carbon fiber reinforced phosphate porous ceramics composites were prepared by acupuncture and in-situ solidification vacuum-assisted liquid-phase infiltration method. The tensile strength of composite was tested by universal testing machine, the microstructures of the specimen were observed by scanning electron microscopy while the thermal analysis was detected by Thermo Gravimetric Analyzer. The results show that the carbon fiber reinforced phosphate porous ceramics composites which is prepared by the technology showed above have a pore rate of 63.7%.The tensile strength reached 50.2MPa with an average pore size of at most 50μm.It also has good thermal shock resistance.


2008 ◽  
Vol 68 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Jared H. Weaver ◽  
James Yang ◽  
Anthony G. Evans ◽  
Frank W. Zok

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


1985 ◽  
Vol 64 ◽  
Author(s):  
Surendra P. Shah

ABSTRACTDespite its extensive use, low tensile strength has been recognized as one of the major drawbacks of concrete. Although one has learned to avoid exposing concrete structures to adverse static tensile load, these cannot be shielded from short duration dynamic tensile stresses. Such loads originate from sources such as impact from missiles and projectiles, wind gusts, earthquakes and machine vibrations. The need to accurately predict the structural response and reserve capacity under such loading has led to an interest in the mechanical properties of the component materials at high rates of straining.One method to improve the resistance of concrete when subjected to impact and/or impulsive loading is by the incorporation of randomly distributed short fibers. Concrete (or Mortar) so reinforced is termed fiber reinforced concrete (FRC). Moderate increase in tensile strength and significant increases in energy absorption (toughness or impact-resistance) have been reported by several investigators in static tests on concrete reinforced with randomly distributed short steel fibers. A theoretical model to predict fracture toughness of FRC is proposed. This model is based on the concept of nonlinear elastic fracture mechanics.As yet no standard test methods are available to quantify the impact resistance of such composites, although several investigators have employed a variety of tests including drop weight, swinging pendulums and the detonation of explosives. These tests though useful in ascertaining the relative merits of different composites do not yield basic material characteristics which can be used for design.The author has recently developed an instrumented Charpy type of impact test to obtain basic information such as load-deflection relationship, fracture toughness, crack velocity and load-strain history during an impact event. From this information, a damage based constitutive model was proposed. Relative improvements in performance due to the addition of fibers as observed in the instrumented tests are also compared with other conventional methods.


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