Fracture Behavior of SiC-TiB2 Composite Measured by Different Test Methods

2011 ◽  
Vol 492 ◽  
pp. 14-17
Author(s):  
Liang Jiang ◽  
Yu Hong Chen ◽  
Bin Chen ◽  
Wen Zhou Sun
Keyword(s):  
Fracture Toughness ◽  
Fracture Behavior ◽  
Test Methods ◽  
Beam Specimen ◽  
Single Edge ◽  
Indentation Method ◽  
Flexure Strength ◽  
Sintering Additive ◽  
Varied Degree ◽  
Selection Of

SiC-TiB2composite was prepared by boron (B) and carbon(C) as sintering additive via presureless sintering in 2180°C. Fracture toughness of SiC-TiB2measured by indentation method and single edge notched beam specimen tenichques were analyzed and compared, and the most suitable indentation method equation was confirmed. Results revealed that the fracture toughness and flexure strength of the materials were influenced at varied degree by the content of TiB2, which had no effect on the selection of the most suitable equation for calculating the fracture toughness of the materials by indentation method. The fracture toughness decreases with the increasing TiB2content. When the TiB2content was 30%, SiC-TiB2composite had the best fracture toughness.

Fracture Behavior of Silicon Carbide Measured by Different Test Methods

2010 ◽  
Vol 177 ◽  
pp. 140-143
Author(s):  
Liang Jiang ◽  
Yu Hong Chen ◽  
Fei Han ◽  
Liang Jiang
Keyword(s):  
Fracture Toughness ◽  
Fracture Behavior ◽  
Test Methods ◽  
Single Edge ◽  
Relative Deviation ◽  
Sic Ceramic ◽  
Indentation Crack ◽  
Real Value ◽  
Indentation Methods ◽  
Computational Equation

Single edge notched beam (SENB) and indentation methods (IM) were used to test the fracture toughness (KIC) of SiC ceramic in present work. Both of testing results were compared. The applicative computational equation of indentation crack was determined through studying indentation morphology formed by IM. The results showed that the indentation crack in SiC could be Babcock crack, and the KIC value calculated by Niihara (P) indentation equation approximated to real value mostly with minimum relative deviation.

Assessing Low-Constraint Fracture Toughness Test Methods Using Clamped SENT Specimens

2019 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Tom McGaughy
Keyword(s):  
Fracture Toughness ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Test Methods ◽  
Fracture Toughness Test ◽  
Single Edge ◽  
Gas Industry ◽  
End Conditions ◽  
The Difference ◽  
Low Constraint

Abstract The low-constraint fracture toughness can be measured using a single edge-notched tension (SENT) specimen in the clamped-end conditions. The SENT specimen has been used in the oil and gas industry in the strain-based design and the crack assessment for transmission pipelines. Since 2006 when DNV published the first SENT test practice, many investigations have been done, and various SENT test methods were developed, including CANMET and ExxonMobil methods in terms of the J-integral and CTOD. The effort led to the first SENT test standard BS 8571 being published in 2014. However, the experimental evaluation methods remain in developing, and different methods may determine inconsistent results. For this reason, the present paper gives a brief review on SENT fracture testing and assesses the available test methods, including progresses on study of stress intensity factor, geometric eta factors, elastic compliance equation, and constraint m factor as well. The difference between J-converted CTOD and double clip gage measured CTOD is also discussed. On those bases, agreements and challenges in SENT testing are identified. The results provide a direction for further investigation to improve the current SENT test methods.

Fractography and Fracture Toughness Measurement

2009 ◽  
Vol 409 ◽  
pp. 17-27 ◽  
Author(s):  
Roger Morrell
Keyword(s):  
Fracture Toughness ◽  
Surface Crack ◽  
Ceramic Materials ◽  
Test Methods ◽  
Fracture Toughness Test ◽  
Single Edge ◽  
Fracture Toughness Measurement ◽  
Beam Method ◽  
Toughness Measurement ◽  
Good Agreement

Using a variety of advanced ceramic materials, a comparison has been conducted of fracture toughness test methods using the single edge vee-notch beam method and the surface crack in flexure method, the latter restricted to optical fractography. Good agreement has been found between the two methods on materials which were amenable to the SCF method. It has further been shown that the SEVNB method can produce reliable results on materials to which the SCF method is not readily applicable.

scholarly journals Single Edge Notch Bend (SENB) of Kenaf/Fibreglass Hybrid Composites

2019 ◽  
Vol 8 (4) ◽  
pp. 6967-6971
Keyword(s):  
Fracture Toughness ◽  
Outer Layer ◽  
Hybrid Composites ◽  
Strain Energy Release ◽  
Weight Fraction ◽  
Natural Fibre ◽  
Test Methods ◽  
Standard Test ◽  
Single Edge ◽  
Layer Arrangement

Kenaf is known for many years as a typical crop that can be used in various applications such as in automotive, and building structure. Along with the depletion and environmental issues raised nowadays by excessively used of man-made synthetic fibres make the natural fibre to become popular and favourable to be implemented. This paper discusses on the development of long kenaf fibre reinforced polyester matrix composite. Total weight of about 40% fibre fraction was selected. In this study, the addition of about 10% weight fraction of fibreglass in the composite system is needed in order to strengthen the composite material and also to retain its reliability and robustness in their applications. Thus, preparation of two different layer arrangement of kenaf and fibreglass were conducted viz. (i) kenaf at inner layer and fibreglass at outer layer ([0o 90o ]K/FG2p/[90o 0 o ]k [0o 90o ]K) (ii) kenaf at outer layer and fibreglass at inner layer (FG/[0o 90o /90o 0 o ]K/FG). All configuration samples were fabricated by hand lay-up and cold press technique. Fracture toughness testing was carried out using a single edge notched bend specimen at a loading rate of 10mm/min. All samples were prepared according to ASTM D5045 (Standard Test Methods for Plane-Strain Fracture Toughness and Strain Energy Release Rate of Plastic Materials). Results obtained from SENB test were then evaluated and discussed. It can be used as a guideline or reference for further research on this type of polymer composite.

Microstructure and Mechanical Properties of Sm1-xSrxCo0.2Fe0.8O3

2000 ◽  
Vol 15 (7) ◽  
pp. 1505-1513 ◽  
Author(s):  
Y-S. Chou ◽  
J. W. Stevenson ◽  
T. R. Armstrong ◽  
J. S. Hardy ◽  
K. Hasinska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Indentation Fracture ◽  
Flexure Strength ◽  
Indentation Toughness ◽  
Indentation Fracture Toughness ◽  
Microhardness Indentation ◽  
Biaxial Flexure

The room temperature mechanical properties of a mixed conducting perovskite Sm1?xSrxCo0.2Fe0.8O3 (x = 0.2 to 0.8) were examined. Density, crystal phase, and microstructure were characterized. It was found that the grain size increased abruptly with increasing Sr content. Mechanical properties of elastic modulus, microhardness, indentation fracture toughness, and biaxial flexure strength were measured. Young's modulus of 180–193 GPa and shear modulus of 70–75 GPa were determined. The biaxial flexure strength was found to decrease with increasing Sr content from ∼70 to ∼20 MPa. The drop in strength was due to the occurrence of extensive cracking. Indentation toughness showed a similar trend to the strength in that it decreased with increasing Sr content from ∼1.1 to ∼0.7 MPa m1/2. In addition, fractography was used to characterize the fracture behavior in these materials.

Study on tearing tests and the determination of fracture toughness of PVC-coated fabric

2021 ◽  
pp. 152808372199394
Author(s):  
Han Bao ◽  
Minger Wu ◽  
Xubo Zhang
Keyword(s):  
Fracture Toughness ◽  
Failure Modes ◽  
Membrane Surface ◽  
Finite Size ◽  
Theoretical Method ◽  
Test Methods ◽  
Gauge Length ◽  
Test Method ◽  
Single Edge ◽  
Tearing Resistance

In this study, detailed uniaxial in-plane tearing tests including uniaxial central, single-edge notched, and trapezoidal tearing tests of a type of polyvinylchloride (PVC)-coated polyester fiber fabric were conducted. Two types of tearing failure modes, brutal and progressive, were examined. In addition to differences in the descending sections of the stress–displacement curves and the membrane surface morphology near the crack, it was found that the uniaxial central tearing test could be replaced by the corresponding single-edge notched tearing test to minimize the usage of test materials. The configuration of the single-edge notched specimen, including the gauge length and width, was investigated to determine the conditions under which the tearing resistance of the practically nearly infinite membrane surface can be studied with finite-size specimens. To obtain the fracture toughness GIC, which characterizes the ability of materials to prevent crack growth, a theoretical method and two test methods were introduced. After comparing the methods, the test method based on the area of the parallelogram obtained from the zigzag wave in the descending section of the load–displacement curves was proved to be superior. The value of GIC obtained with this simple test method was relatively stable, and it could be used to evaluate the tearing resistance and calculate the tearing strength of the coated fabrics.

Fabrication and Mechanical Properties of TZ-3Y20A /Mo Multilayer Composites

2005 ◽  
Vol 492-493 ◽  
pp. 605-608
Author(s):  
Lian Meng Zhang ◽  
Li Chun Yu ◽  
Dao Ren Gong ◽  
Qiang Shen
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Fracture Surface ◽  
Crack Deflection ◽  
Single Edge ◽  
Individual Layer ◽  
Flexure Strength ◽  
Three Point Bending ◽  
Multilayer Composites ◽  
Work Of Fracture

In the present work, TZ-3Y20A/Mo multilayer composites were prepared by sedimentation method. Appropriate settling parameters were chosen and green bodies of multilayer composites were obtained by settling TZ-3Y20A powder and Mo powder in turn according to the designed individual layer thickness. Then green laminates were hot pressed at 1773K for an hour under the pressure of 20MPa. Three-point Bending and Single Edge Notched Beam (SENB) tests were adopted to evaluate the flexure strength and fracture toughness of the samples. The results showed that, compared to TZ-3Y20A ceramics, the fracture toughness and the work of fracture increased due to the layered structure. The microstructure and crack deflection of the fracture surface of the laminated composites was also observed by optical microscopy.

Comparison of R-Curve Behavior of Si3N4 Measured by Indentation Method and Single-Edge V-Notched Beam Technique (SEVNB)

2009 ◽  
Vol 409 ◽  
pp. 308-312
Author(s):  
Jana Špaková ◽  
Ján Dusza
Keyword(s):  
Fracture Toughness ◽  
Crack Opening ◽  
Single Edge ◽  
Indentation Fracture ◽  
Indentation Method ◽  
Indentation Toughness ◽  
Indentation Fracture Toughness ◽  
Beam Technique

Study compare R-curve behaviour of silicon nitride obtained using Vickers indented beam specimens and single edge V-notched beam (SEVNB). R-curve measurement realized by Vickers indented beam was reported by Krause. Crack growth using single edge V-notched beam was observed in situ. The indentation experiments, in comparison with SEVNB method revealed higher R-curve values (KR=3.3 – 4.8 MPa.m1/2). The discrepancy in the R-curve results is attributed to inaccuracy related to the determination of indentation toughness. The indentation fracture toughness may include the aspects of crack opening behaviour, residual indentation stress intensity.

Effect of Annealing on the Microstructures and Mechanical Properties of Mo3Si-Mo5Si3 Eutectic

2004 ◽  
Vol 449-452 ◽  
pp. 697-700
Author(s):  
Hai Bo Yang ◽  
Wei Li ◽  
Ai Dang Shan ◽  
Jian Sheng Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Strain Rate ◽  
Eutectic Alloy ◽  
Vickers Hardness ◽  
Room Temperature ◽  
Beam Specimen ◽  
Single Edge ◽  
Arc Melting ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of arc-melting processed Mo3Si-Mo5Si3 eutectic have been investigated. The Vickers hardness of Mo3Si-Mo5Si3 eutectic alloy at room temperature is on the order of 1350Hv. The fracture toughness value of the alloy at room temperature is 1.39MPam1/2 measured by Single edge-notched beam specimen technique and 1.61MPam1/2 measured by Indentation technique. The compressive strengths at 1300 oC and 1400 oC under a strain rate of 10-4s-1 are about 550MPa and 300MPa respectively.

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