scholarly journals Evaluation of Fast Fracture Strength of Ceramic Components Under Multiaxial Stress States

1992 ◽  
Author(s):  
H. Uchimura ◽  
A. Kokaji ◽  
M. Kaji
Keyword(s):  
Experimental Data ◽  
Probability Distribution Function ◽  
Fracture Probability ◽  
Surface Cracks ◽  
Multiaxial Stress ◽  
Fracture Criteria ◽  
Ceramic Components ◽  
Stress States ◽  
Fast Fracture ◽  
Sintered Silicon

Several fracture criteria were studied under multiaxial stress states by Matsuo’s multiaxial fracture probability distribution function including effects of both volume and surface cracks. Tested material was a pressureless-sintered silicon nitride. Tensile (compressive)-torsional tests revealed that experimental data were satisfactorily described by Shitty’s empirical criterion for C=1.46. Good agreements for a spin and a thermal shock tests were obtained applying the Weibull parameters and the Shetty’s parameter.

Reliability Evaluation of Structural Ceramics Under Multiaxial Stress State

1998 ◽  
Author(s):  
Takashi Ono ◽  
Masaki Kaji ◽  
Michiaki Nishimura
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Stress State ◽  
Fracture Probability ◽  
Test Method ◽  
Structural Ceramics ◽  
Multiaxial Stress ◽  
Fatigue Lifetime ◽  
Empirical Parameter ◽  
Multiaxial Stress State

Strength and fatigue lifetime of structural ceramics under multiaxial stress state have been estimated and compared with experimental data. Biaxial strength tests were done by an anticlastic bending test method at room temperature. Biaxial fatigue tests were done by anticlastic bending and also ring-on-ring test method at 1200°C in air. Fracture probability and lifetime were predicted on the basis of a Weibull multiaxial distribution function and subcritical crack growth, using the results of stress analyses by the finite element method. Modified maximum hoop stress theory including an empirical parameter, T, was applied to the equivalent normal stress in the multiaxial distribution function. The empirical parameter T represents a shear stress sensitivity to mixed-mode fracture due to a grain interlocking effect. It has been confirmed that the predicted fracture probability and the fatigue lifetime agrees well with the experimental data if grain interlocking effects are taking into account.

scholarly journals Fracture Behavior of Sintered Silicon Nitride under Multiaxial Stress States

1988 ◽  
Vol 96 (1113) ◽  
pp. 539-545 ◽  
Author(s):  
Isao ODA ◽  
Minoru MATSUI ◽  
Takao SOMA ◽  
Masaaki MASUDA ◽  
Naohito YAMADA
Keyword(s):  
Silicon Nitride ◽  
Fracture Behavior ◽  
Multiaxial Stress ◽  
Stress States ◽  
Sintered Silicon

Ceramics Reliability: Statistical Analysis of Multiaxial Failure Using the Weibull Approach and the Multiaxial Elemental Strength Model

1988 ◽  
Author(s):  
Jacques Lamon
Keyword(s):  
Experimental Data ◽  
Structural Design ◽  
Mixed Mode ◽  
Bending Test ◽  
Second Step ◽  
Strength Model ◽  
Precise Evaluation ◽  
Ceramic Components ◽  
Stress States ◽  
Mode Failure

Methodology for designing reliable ceramic components requires a precise evaluation and correlation of strengths in different stress states. The present paper compares the merits of the Weibull approach and the Multiaxial Elemental Strength model on an experimental case involving mixed mode failure in the presence of bimodal flaw populations (surface and volume flaws). The experimental data were obtained using flexure specimens of Si3N4 tested at various spans, with the purpose of enhancing shearing effects. The analysis of data was refined by developing an advanced post-processor program to finite element codes, for failure probability determination based upon the Barnett-Freudenthal approximation of the Weibull approach and the Multiaxial Elemental Strength Model. In a second step, the strengths of the specimens exhibiting failures from the two concurrent populations of flaws (intermediate span) were predicted using both approaches from data obtained with different span lengths (long and short spans). Comparison with experimental data showed that the Multiaxial Elemental Strength Model is an improvement over the Weibull approach. It also allowed the short span bending test to be assessed. Finally, important implications for structural design with ceramics are discussed.

scholarly journals Fracture Behavior of Sintered Silicon Nitride under Multiaxial Stress States (Part 2)

1991 ◽  
Vol 99 (1151) ◽  
pp. 574-581 ◽  
Author(s):  
Hideyoshi TSURUTA ◽  
Naohito YAMADA ◽  
Yoshizumi NAKASUJI ◽  
Masaaki MASUDA ◽  
Minoru MATSUI
Keyword(s):  
Silicon Nitride ◽  
Fracture Behavior ◽  
Multiaxial Stress ◽  
Stress States ◽  
Sintered Silicon

scholarly journals A Study of Yielding and Plasticity of Rapid Prototyped ABS

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1495
Author(s):  
Dan-Andrei Șerban ◽  
Cosmin Marșavina ◽  
Alexandru Viorel Coșa ◽  
George Belgiu ◽  
Radu Negru
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Plastic Flow ◽  
Plane Stress ◽  
Yield Criterion ◽  
Numerical Analyses ◽  
Flow Potential ◽  
Stress States ◽  
State Configuration

In this article, the yielding and plastic flow of a rapid-prototyped ABS compound was investigated for various plane stress states. The experimental procedures consisted of multiaxial tests performed on an Arcan device on specimens manufactured through photopolymerization. Numerical analyses were employed in order to determine the yield points for each stress state configuration. The results were used for the calibration of the Hosford yield criterion and flow potential. Numerical analyses performed on identical specimen models and test configurations yielded results that are in accordance with the experimental data.

scholarly journals Verification of Brittle Fracture Criteria for Bimaterial Structures

2014 ◽  
Vol 8 (1) ◽  
pp. 44-48
Author(s):  
Grzegorz Mieczkowski ◽  
Krzysztof Molski
Keyword(s):  
Experimental Data ◽  
Composite Materials ◽  
Cyclic Loading ◽  
Brittle Fracture ◽  
Axial Loading ◽  
Loading Conditions ◽  
Fracture Criteria ◽  
Interfacial Cracks ◽  
Theoretical Results ◽  
Brittle Fracture Criteria

Abstract The increasing application of composite materials in the construction of machines causes strong need for modelling and evaluating their strength. There are many well known hypotheses used for homogeneous materials subjected to monotone and cyclic loading conditions, which have been verified experimentally by various authors. These hypotheses should be verified also for composite materials. This paper provides experimental and theoretical results of such verifications for bimaterial structures with interfacial cracks. Three well known fracture hypotheses of: Griffith, McClintock and Novozhilov were chosen. The theoretical critical load values arising from each hypotheses were compared with the experimental data including uni and multi-axial loading conditions. All tests were carried out with using specially prepared specimens of steel and PMMA.

Behavior of Lode Dependent Plasticity at Plane Strain Condition and its Implication to Ductile Fracture

2016 ◽  
Vol 258 ◽  
pp. 213-216 ◽  
Author(s):  
František Šebek ◽  
Jindrich Petruška ◽  
Petr Kubík
Keyword(s):  
Ductile Fracture ◽  
Plane Strain ◽  
Uniaxial Stress ◽  
Complex Materials ◽  
Fracture Criteria ◽  
Dependent Plasticity ◽  
Ductile Fracture Criteria ◽  
Stress States ◽  
Aluminum Alloy 2024 ◽  
Von Mises

Variety of metals are complex materials exhibiting various behavior under different loading. Many metallic materials exhibit Tresca-like behavior rather than von Mises. It means different behavior in tension under plane strain and uniaxial stress conditions. This might be described by Lode dependent plasticity which should result in better prediction in force or torque responses of material tests. Good agreement between computation and experiment is also very important when calibrating the ductile fracture criteria. Several tests under plane strain and uniaxial stress states were carried out on aluminum alloy 2024-T351 where the Lode dependency was significant. The Lode dependent plasticity was implemented along with von Mises and Tresca-like yield criteria, which resulted in improvement of force–displacement responses of plane strain tests simulations. But it also caused significant change in the stress state of tensile flat and grooved plates which wrongly approached uniaxial tension condition. This inconvenience prevents plane strain experiments from using for calibration of ductile fracture criteria under these circumstances.

The Revised Universal Slope Method to Predict the Low-Cycle Fatigue Lives of Elbow and Tee Pipes

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Hiun Nagamori ◽  
Koji Takahashi
Keyword(s):  
Experimental Data ◽  
Internal Pressure ◽  
Low Cycle Fatigue ◽  
Experimental Studies ◽  
High Accuracy ◽  
Universal Method ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Slope Method ◽  
Stress States

The stress states of elbow and tee pipes are complex and different from those of straight pipes. The low-cycle fatigue lives of elbows and tees cannot be predicted by Manson's universal slope method; however, a revised universal method proposed by Takahashi et al. was able to predict with high accuracy the low-cycle fatigue lives of elbows under combined cyclic bending and internal pressure. The objective of this study was to confirm the validity of the revised universal slope method for the prediction of low-cycle fatigue behaviors of elbows and tees of various shapes and dimensions under conditions of in-plane bending and internal pressure. Finite element analysis (FEA) was carried out to simulate the low-cycle fatigue behaviors observed in previous experimental studies of elbows and tees. The low-cycle fatigue behaviors, such as the area of crack initiation, the direction of crack growth, and the fatigue lives, obtained by the analysis were compared with previously obtained experimental data. Based on this comparison, the revised universal slope method was found to accurately predict the low-cycle fatigue behaviors of elbows and tees under internal pressure conditions regardless of differences in shape and dimensions.

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