Experiments and Modeling of Failure and Fragmentation of Alumina Cylinders under Uniaxial Compression

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Yong-Gang Wang ◽  
Jian-Dong Hu ◽  
Feng-Hua Zhou
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Uniaxial Compression ◽  
High Speed ◽  
Cylindrical Specimen ◽  
Specimen Size ◽  
Fragmentation Model ◽  
High Speed Video ◽  
Axial Splitting

AbstractQuasistatic compressive strength of alumina cylinders was measured using specimen of two sizes. The strength of the material was dependent on the specimen size. High speed video photography showed that the failure of the cylindrical specimen started from axial splitting, and after failure the specimen fragmentized into small pieces. A fragmentation model was proposed for estimating the average sizes of the fragments. The calculated fragment sizes agreed reasonably well with the experimental data. By using Ls-Dyna software, the failure of cylindrical specimen containing pre-existing crack-like flaws had been simulated.

Experiments and Modeling of Failure and Fragmentation of Alumina Cylinders under Uniaxial Compression

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Yong-Gang Wang ◽  
Jian-Dong Hu ◽  
Feng-Hua Zhou
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Uniaxial Compression ◽  
High Speed ◽  
Cylindrical Specimen ◽  
Specimen Size ◽  
Fragmentation Model ◽  
High Speed Video ◽  
Axial Splitting

AbstractQuasistatic compressive strength of alumina cylinders was measured using specimen of two sizes. The strength of the material was dependent on the specimen size. High speed video photography showed that the failure of the cylindrical specimen started from axial splitting, and after failure the specimen fragmentized into small pieces. A fragmentation model was proposed for estimating the average sizes of the fragments. The calculated fragment sizes agreed reasonably well with the experimental data. By using Ls-Dyna software, the failure of cylindrical specimen containing pre-existing crack-like flaws had been simulated.

scholarly journals Kinematic parameters of goats walking on different slopes and biomimetic walking mechanisms

2017 ◽  
Author(s):  
Fu Zhang ◽  
Yafei Wang ◽  
Wei Wang ◽  
Keyword(s):  
Experimental Data ◽  
Theoretical Basis ◽  
High Speed ◽  
Rate Of Change ◽  
Kinematic Parameters ◽  
High Speed Video ◽  
Experimental Image ◽  
Displacement Speed ◽  
Walking Mechanism ◽  
Uphill Walking

A comparative analysis of the kinematic parameters of a goat on different slopes was conducted to study the kinematic parameters of goats on different slopes with walking mechanics. The uphill walking processes on different slopes (0°, 5°, 10°, 15°, 20°, 25° and 30°) were recorded by a high speed video system (VRI Phantom M110). The experimental image results were processed and analyzed using PCC and MATLAB software. The kinematic parameters were obtained from the goat walking on different slopes; these parameters are the changes of centroid with displacement, speed with time, and acceleration with time. As the gradient in the uphill process increases, the range of centroid fluctuation ranges from 0.079 to 0.59 and the rate of change ranges from 0.4 to 2.2 m/s, while the acceleration of the goat slope decreases. The present research can provide theoretical basis and experimental data for the design of a biomimetic agricultural slope walking mechanism.

scholarly journals A Finite Element Failure Model for Notched Laminated Composites Loaded in Compression

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300
Author(s):  
C. Soutis ◽  
R. Tenchev
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Compressive Strength ◽  
Stress Analysis ◽  
Uniaxial Compression ◽  
Progressive Damage ◽  
Failure Model ◽  
Damage Growth ◽  
Linear Finite Element ◽  
Element Failure

This paper describes a progressive damage failure model which is making an attempt to predict damage growth and ultimate compressive strength of notched laminates subjected to uniaxial compression. A non-linear finite element programme is developed to perform the ply-by-ply stress analysis and numerical results are compared with existing experimental data [1,2]; the agreement is acceptable.

Dynamic Mechanical Behavior of Two Fiber-Reinforced Composites

2012 ◽  
Vol 525-526 ◽  
pp. 261-264
Author(s):  
Y.Z. Guo ◽  
X. Chen ◽  
Xi Yun Wang ◽  
S.G. Tan ◽  
Z. Zeng ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Rate Dependent ◽  
Dynamic Loadings ◽  
Axial Splitting

The mechanical behavior of two composites, i.e., CF3031/QY8911 (CQ, hereafter in this paper) and EW100A/BA9916 (EB, hereafter in this paper), under dynamic loadings were carefully studied by using split Hopkinson pressure bar (SHPB) system. The results show that compressive strength of CQ increases with increasing strain-rates, while for EB the compressive strength at strain-rate 1500/s is lower then that at 800/s or 400/s. More interestingly, most of the stress strain curves of both of the two composites are not monotonous but exhibit double-peak shape. To identify this unusual phenominon, a high speed photographic system is introduced. The deformation as well as fracture characteristics of the composites under dynamic loadings were captured. The photoes indicate that two different failure mechanisms work during dynamic fracture process. The first one is axial splitting between the fiber and the matrix and the second one is overall shear. The interficial strength between the fiber and matrix, which is also strain rate dependent, determines the fracture modes and the shape of the stress/strain curves.

Solidification Front Velocity of Ternary Titanium-Aluminides

1995 ◽  
Vol 398 ◽  
Author(s):  
M. Wettlaufer ◽  
J. Laakmann
Keyword(s):  
Experimental Data ◽  
Temperature Measurement ◽  
Solidification Front ◽  
High Speed ◽  
Titanium Aluminides ◽  
Front Velocity ◽  
Experimental Results ◽  
Video System ◽  
High Speed Video ◽  
Bulk Undercooling

ABSTRACTTernary titanium-aluminides with compositions of Ti51Al47Fe2, Ti51A147Cr2 and Ti51Al47Mn2 were investigated with respect to the correlation of their solidification front velocity v and bulk undercooling ΔT. The observation of the solidification front during the recalescence event has been realized using a high speed video system capable of recording up to 12,000 pictures per second. The temperature measurement was carried out by pyrometry, avoiding contact with the sample. The comparison of the experimental data with the LKT-theory (Lipton, Kurz, Trivedi; [1]) refers to a primary (hcp) β-Ti solidification for undercoolings below ΔT≈ 130 K and primary (bcc) α-Ti solidification for ΔT≥ 130 K. For undercoolings ≥ 150 K the theory differs greatly from the experimental results.The maximum undercoolings achieved were 268 K (Ti51Al47Fe2), 285 K (Ti51Al47Cr2) and 280 K (Ti51Al47Mn2), corresponding to a solidification front velocity v ≈ 9-10 m/s for all alloys.

Experimental data on the mechanism of subcooled water boiling: high-speed video shooting

2014 ◽  
Vol 21 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Yu. A. Zeigarnik ◽  
K. A. Khodakov ◽  
Yu. L. Shekhter
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
High Speed Video ◽  
Subcooled Water

Sea Ice Crushing Under Uniaxial Compression and Tension Models

2004 ◽  
Author(s):  
Stanislav A. Vershinin ◽  
Pavel A. Truskov ◽  
Konstantin V. Kouzmitchev
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Sea Ice ◽  
Strain Rate ◽  
Phenomenological Models ◽  
Uniaxial Compression ◽  
Constant Strain Rate ◽  
Specimen Size ◽  
Grain Structure ◽  
Testing Methodology

The paper describes phenomenological models of ice crushing in compression and tension at a constant strain rate. They present the fundamentals of loaded ice behavior depending on objective factors, such as ice grain structure, salinity and temperature, and on subjective factors such as specimen size and testing methodology. The theoretical analysis is compared with experimental data.

scholarly journals Kinematic parameters of goats walking on different slopes and biomimetic walking mechanisms

2017 ◽  
Author(s):  
Fu Zhang ◽  
Yafei Wang ◽  
Wei Wang ◽  
Keyword(s):  
Experimental Data ◽  
Theoretical Basis ◽  
High Speed ◽  
Rate Of Change ◽  
Kinematic Parameters ◽  
High Speed Video ◽  
Experimental Image ◽  
Displacement Speed ◽  
Walking Mechanism ◽  
Uphill Walking

A comparative analysis of the kinematic parameters of a goat on different slopes was conducted to study the kinematic parameters of goats on different slopes with walking mechanics. The uphill walking processes on different slopes (0°, 5°, 10°, 15°, 20°, 25° and 30°) were recorded by a high speed video system (VRI Phantom M110). The experimental image results were processed and analyzed using PCC and MATLAB software. The kinematic parameters were obtained from the goat walking on different slopes; these parameters are the changes of centroid with displacement, speed with time, and acceleration with time. As the gradient in the uphill process increases, the range of centroid fluctuation ranges from 0.079 to 0.59 and the rate of change ranges from 0.4 to 2.2 m/s, while the acceleration of the goat slope decreases. The present research can provide theoretical basis and experimental data for the design of a biomimetic agricultural slope walking mechanism.

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