Labeled Weibull Plot of a C-Derived Si3N4-SiC Nanocomposite

2005 ◽  
Vol 290 ◽  
pp. 292-295
Author(s):  
Monika Kašiarová ◽  
Ján Dusza ◽  
Miroslav Hnatko ◽  
Pavol Šajgalík
Keyword(s):  
Weibull Distribution ◽  
Bending Strength ◽  
Four Point Bending ◽  
Weibull Plot ◽  
Technological Defects

Four-point bending strength and Weibull distribution of the strength values of a carbon derived Si3N4-SiC nanocomposite have been investigated. The fracture origins were identified and characterized and a “labeled Weibull plot” was constructed. The fracture origins are surface, subsurface and volume located technological defects with a dimension from 10 µm to 180 µm, mainly in the form of cluster of pores and large SiC grains.

Bending and Contact Strength of a Si3N4+SiC Micro/Nano Composite

2007 ◽  
Vol 567-568 ◽  
pp. 177-180
Author(s):  
Ján Dusza ◽  
Monika Kašiarová ◽  
Lucia Hegedűsová ◽  
Miroslav Hnatko ◽  
Pavol Šajgalík
Keyword(s):  
Weibull Modulus ◽  
Bending Strength ◽  
Strength Test ◽  
Contact Strength ◽  
Effective Volume ◽  
Characteristic Strength ◽  
Four Point Bending ◽  
Weibull Statistical Analysis ◽  
Technological Defects

Bending and contact strength of a carbon derived in-situ reinforced Si3N4-SiC micro/nanocomposite have been investigated. Four-point bending strength was measured using specimens with different effective volume and Weibull statistical analysis has been used for characterization of the strength values in the form of characteristic strength and Weibull modulus. The characteristic strength values of the investigated composite were σ0 = 675 MPa and σ0 = 832 MPa with the Weibull modulus of 6,4 and 8,6 for the specimens with effective volume 15,9 mm3 and 1,28 mm3 respectively. Contact strength of the investigated material was carried out using sphere on sphere and roller on roller methods and the obtained results are σ0S = 1997 MPa, σ0R = 1242 MPa, and mS = 17,1 mR = 6. Fracture origins in the specimens with effective volume of 15.9 mm3 tested in four-point bending were surface and volume located technological defects with dimensions from 10 μm to 180 μm, mainly in the form of clusters of pores and large SiC grains. Fracture mirror sizes were measured and the mirror constant was calculated. Fracture origins in the specimens with effective volume of 1.28 mm3 tested in four-point bending were surface (subsurface) defects with the same type as for the specimens with a higher effective volume. The fracture during the contact strength test „roller/roller“ has been initiated under the surface of the specimens and during the contact strength test „sphere/sphere“ by creation and growth of the cone cracks to critical size.

Characteristics of Low Temperature Degradation Free ZTA for Artificial Joint

2014 ◽  
Vol 631 ◽  
pp. 18-22 ◽  
Author(s):  
Junji Ikeda ◽  
Takayuki Murakami ◽  
Takayoshi Shimozono ◽  
Reiji Watanabe ◽  
Mikio Iwamoto ◽  
...  
Keyword(s):  
Low Temperature ◽  
Phase Stability ◽  
Mechanical Characteristics ◽  
Bending Strength ◽  
Accelerated Aging ◽  
Ceramic Materials ◽  
Wear Property ◽  
Artificial Joint ◽  
Four Point Bending ◽  
Bearing Materials

Low temperature degradation free Zirconia toughened alumina (ZTA) has been developed. It is reported that ZTA has higher mechanical strength compared to alumina due to the stress induced transformation and spontaneously transformation of zirconia phase on some ZTA have been occurred. For achieving the higher reliability of artificial joint prosthesis alternative to alumina and other ceramic materials, it is necessary to improve and validate the both mechanical characteristics and phase stability at the same time. We evaluated that microstructure, mechanical characteristics and phase stability of newly developed ZTA (BIOCERAM®AZUL). It was confirmed that four-point bending strength and weibull modulus were extreamly high, and ZTA has higher reliability. There were no significant changes and deterioration in four-point bending strength, crystal structure and wear property with and without accelerated aging test. Newly developed ZTA not only with high mechanical characteristics but also with phase stability could be quite useful as bearing materials in artificial joints for longer clinical use.

Research on Damage and Bending Properties of AZ31 Magnesium Alloy

2012 ◽  
Vol 184-185 ◽  
pp. 1163-1166
Author(s):  
Xi An Xie ◽  
Gao Feng Quan
Keyword(s):  
Magnesium Alloy ◽  
Applied Load ◽  
Bending Strength ◽  
Az31 Magnesium Alloy ◽  
Bending Test ◽  
Bending Properties ◽  
Four Point Bending ◽  
Heat Treated ◽  
Four Point Bending Test ◽  
Initial Cracks

Through the four-point bending test of lath-shaped heat treated AZ31 magnesium alloy, the bending properties and damage characteristics were explored. The results show that the optimal bending strength of the magnesium alloy were 355.1MPa and 259.2MPa for extruded and cast samples, respectively, after corresponding heat treatment with 350°C, 90min and 400°C, 30min. The initial cracks both occurred at the loading point after applied load exceeded the yield limit of AZ31 magnesium alloy. Surface bump, cracks and other damage morphology accompanied by a large number of twinning organizations were found on the surface of the samples.

Fracture Mechanics of Y2O3 Ceramics at High Temperatures

2014 ◽  
Vol 89 ◽  
pp. 88-93
Author(s):  
Marek Boniecki ◽  
Zdzislaw Librant ◽  
Władysław Wesołowski ◽  
Magdalena Gizowska ◽  
Marcin Osuchowski ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
High Temperature ◽  
Fracture Mechanics ◽  
High Purity ◽  
Room Temperature ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Temperature Changes ◽  
Four Point Bending

Fracture toughness KIc and four-point bending strength σc at high temperature (up to 1500 °C) of Y2O3 ceramics of various grain size were measured. The ceramics were prepared by pressureless air sintering and next hot isostatic pressing of high purity (99.99%) Y2O3 powder. Relative density of about 99 % was achieved. Photos of microstructures revealed small pores distributed mainly inside grains. For smallest grain size (2 - 9 μm) ceramics KIc and σc are almost constant from 20 ° to 1200 °C and next they decrease. For biggest grain size (about 44 μm) they increase up to 800 °C and next they keep constant up to 1200 °C. The micrographs analyses of fracture surfaces indicated that transgranular mode of fracture at room temperature changes to almost intergranular at higher temperatures.

Bending Strength of Cast Materials Reinforced with Hard Particles

2010 ◽  
Vol 457 ◽  
pp. 404-409
Author(s):  
Setsuo Aso ◽  
Hiroyuki Ike ◽  
Ken-Ichi Ohguchi ◽  
Yoshinari Komastu ◽  
Nobuo Konishi
Keyword(s):  
Composite Material ◽  
Bending Strength ◽  
Composite Layer ◽  
Cemented Carbide ◽  
Bending Test ◽  
Spheroidal Graphite ◽  
Four Point Bending ◽  
Hard Particles ◽  
Particle Reinforced Composite ◽  
Insertion Process

Particle reinforcement via the insertion of hard particles is a promising process in materials reinforcing. Particle-reinforced spheroidal graphite martensitic cast iron (SGMC), in which mixed particles of cermet and cemented carbide are dispersed, was achieved by an insertion process. A four-point bending strength test was applied to evaluate the particle composite material. An evaporative pattern process was used on the bending-test specimen to form a composite layer in the central part. Using a combination of three sizes of cermet particles and two sizes of cemented-carbide particles, the bending strength was found to increase with each small-particle combination. The Weibull coefficient m of the four-point bending strength of the particle-reinforced composite material (PRCM) ranged from 4 to 13, and m was large in the specimen with large bending strength.

Fracture behavior of fused quartz with laser-induced internal flaws

1994 ◽  
Vol 9 (7) ◽  
pp. 1780-1788 ◽  
Author(s):  
Y.Z. Li ◽  
M.P. Harmer ◽  
Y.T. Chou
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Bending Strength ◽  
Laser Pulse Energy ◽  
Laser Light ◽  
Threshold Value ◽  
Flaw Size ◽  
Demarcation Line ◽  
Four Point Bending ◽  
Fused Quartz

Pulsed-laser light was used to generate internal flaws in fused quartz. The size of the flaw produced was proportional to the amount of laser pulse energy above a threshold value of 2.5 mJ. Specimens of different flaw sizes were tested at room temperature under four-point bending. The bending strength decreased as the flaw size increased, and a Griffith relationship was established between the lateral flaw size and the critical stress at the flaw tip. Characteristic demarcation lines were observed on the fracture surfaces of specimens with a flaw size greater than 0.25 mm. It is suggested that the formation of the demarcation line is caused by a discontinuous change of stress intensity in the dynamic process of the crack propagation.

Gas Turbine Safety Improvement Through Risk Analysis

1988 ◽  
Vol 110 (2) ◽  
pp. 265-270 ◽  
Author(s):  
T. M. Crosby ◽  
G. L. Reinman
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Risk Analysis ◽  
Weibull Distribution ◽  
Gas Turbine ◽  
System Model ◽  
Weibull Analysis ◽  
System Safety ◽  
Weibull Plot ◽  
Safety Improvement

This paper is intended to provide the engineer with the information necessary to understand certain statistical methods that are used to improve system safety. It will provide an understanding of Weibull analysis, in that it describes when the Weibull distribution is appropriate, how to construct a Weibull plot, and how to use the parameters of the Weibull distribution to calculate risk. The paper will also provide the engineer with a comprehension of Monte Carlo simulation as it relates to quantifying safety risk. The basic components of Monte Carlo simulation are discussed as well as the formulation of a system model and its application in the gas turbine industry.

Contact and Bending Strength Tests of Ceramics: What is the Difference?

2009 ◽  
Vol 409 ◽  
pp. 185-192
Author(s):  
Lucia Hegedűsová ◽  
Alexandra Kovalčíková ◽  
Monika Kašiarová ◽  
Ján Dusza
Keyword(s):  
Bending Strength ◽  
Ceramic Materials ◽  
Contact Test ◽  
Four Point Bending ◽  
Sic Ceramic ◽  
Bending Mode ◽  
Strength Tests ◽  
The Difference

The paper deals with the determination of the characteristic strength and the Weibull modulus m of Si3N4 and SiC ceramic materials using conventional four-point bending and unconventional contact tests between opposite rollers and opposite spheres. Ceramographic and fractographic methods were used for the characterization of strength degrading defects represented by processing flaws and by cracks of different types arising during the loading. The processing flaws influenced the Weibull parameters mainly in the bending mode, and the strength and its scatter in contact modes was influenced by lateral, median and contact end cracks, originated during the contact test using rollers, and by cone cracks originated during the contact test using spheres.

In vitro biomechanical evaluation and comparison of a new prototype locking plate and a limited-contact self compression plate for equine fracture repair

2012 ◽  
Vol 25 (04) ◽  
pp. 273-280
Author(s):  
D. D. Quinteros ◽  
G. A. Abuja ◽  
M. Tarkanian ◽  
L. S. Maranda ◽  
K. Bubeck ◽  
...  
Keyword(s):  
Locking Plate ◽  
Bending Strength ◽  
Fatigue Testing ◽  
Cyclic Fatigue ◽  
Fracture Repair ◽  
Single Cycle ◽  
Four Point Bending ◽  
Metacarpal Bones ◽  
Compression Plate ◽  
Strength And Stiffness

SummaryObjective: To determine if the mechanical properties (strength and stiffness) of a new prototype 4.5 mm broad locking plate (NP-LP) are comparable with those of a traditional 4.5 mm broad limited-contact self compression plate (LC-SCP), and to compare the bending and torsional properties of the NP-LP and LCSCP when used in osteotomized equine third metacarpal bones (MC3).Methods: The plates alone were tested in four-point bending single cycle to failure. The MC3-plate constructs were created with middiaphyseal osteotomies with a 1 cm gap. Constructs were tested in four-point bending single cycle to failure, four-point bending cyclic fatigue, and torsion single cycle to failure.Results: There were not any significant differences in bending strength and stiffness found between the two implants. The MC3-NP-LP construct was significantly stiffer than the MC3-LC-SCP in bending. No other biomechanical differences were found in bending, yield load in torsion, or mean composite rigidity. Mean cycles to failure for bending fatigue testing were similar for both constructs.Clinical significance: The NP-LP was comparable to the LC-SCP in intrinsic, as well as structural properties. The NP-LP construct was more rigid than the LC-SCP construct under four-point bending, and both constructs behaved similarly under four-point bending cyclic fatigue testing and torsion single cycle to failure. The new NP-LP implant fixation is biomechanically comparable to the LC-SCP in a simulated MC3 fracture.

scholarly journals Structural Behavior of High Strength Laced Reinforced Concrete One Way Slab Exposed to Fire Flame

2019 ◽  
Vol 5 (12) ◽  
pp. 2747-2761
Author(s):  
Anas Ibrahim Abdullah
Keyword(s):  
Reinforced Concrete ◽  
Bending Strength ◽  
High Strength ◽  
Bending Test ◽  
Structural Members ◽  
Four Point Bending ◽  
Steady State Temperature ◽  
Average Residual ◽  
Fire Flame ◽  
Geometric Layout

In this study, an experimental investigation had conducted for six high strength laced reinforced concrete one-way slabs to discover the behavior of laced structural members after being exposed to fire flame (high temperature). Self-compacted concrete (SCC) had used to achieve easy casting and high strength concrete. All the adopted specimens were identical in their compressive strength of ( , geometric layout 2000 750 150 mm and reinforcement specifics except those of lacing steel content, three ratios of laced steel reinforcement of (0.0021, 0.0040 and 0.0060) were adopted. Three specimens were fired with a steady state temperature of  for two hours duration and then after the specimens were cooled suddenly by spraying water. The simply supported slabs were tested for flexure behavior with two line loads applied in the middle third of the slab (four-point bending test). The average residual percentage of cubic compression strength and splitting tensile strength were 57.5% and 50% respectively. The outcomes indicated that the residual bending strength of the burned slabs with laced ratios (0.0021, 0.004, 0.006) were (72.56, 70.54 and 70.82%) respectively. However; an increase in the deflection was gained to be (11.34, 14.67 and 17.22%) respectively with respect to non-burned specimens.

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