An Experimental Investigation on Static and Dynamic Fracture Properties of MgAl

2010 ◽  
Vol 97-101 ◽  
pp. 683-686 ◽  
Author(s):  
Wei Zhou Zhong ◽  
Jing Run Luo ◽  
Shun Cheng Song ◽  
Xi Cheng Huang
Keyword(s):  
Crack Tip ◽  
Value Theory ◽  
Initiation Toughness ◽  
Hopkinson Pressure Bar ◽  
Dynamic Stress Intensity Factors ◽  
Static Compression ◽  
Time Dynamic ◽  
Three Point Bending ◽  
Finite Element Software ◽  
Pressure Bar

Three-point bending specimens of MgAl are loaded by MTS material testing equipment and Hopkinson pressure bar. Strength ratio of MgAl subjected to static compression loading is gained. The dynamic response of three-point bending specimen subjected to impact loading is simulated by ABAQUS finite element software. The stress distribution around crack tip is like shape of butterfly. It indicates that stress decreases quickly away from crack tip. Strain gauges are affixed at the swings of butterfly in the experiments and can experience higher strain signal. So the choice of strain gauge position is reasonable. Based on finite displacement method and the least multiplication value theory, dynamic stress intensity factors at different loading velocities are obtained. According to crack initiation time, dynamic initiation toughness is computed. The results indicate that dynamic initiation toughness of MgAl varies at different loading rates and increases with ball velocity.

Quasi-Static and High Strain Rate Uniaxial Compressive Response of Recycled Polycarbonate from Industrial Waste

2020 ◽  
Vol 1012 ◽  
pp. 89-93
Author(s):  
Anderson Oliveira da Silva ◽  
Ricardo Pondé Weber ◽  
Sergio Neves Monteiro
Keyword(s):  
Industrial Waste ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Hopkinson Pressure Bar ◽  
Mechanical Recycling ◽  
Static Compression ◽  
Compressive Response ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Quasi Static Compression

This work evaluates the mechanical and dynamic behavior of recycled polycarbonate (rPC) from industrial waste. This study aims to verify whether the recycled process adopted for polycarbonate promotes both mechanical and dynamic properties values under compressive stress, similar to those found for virgin polycarbonate. The mechanical recycling of the rPC was carried out using the thermoforming technique in a thermal press. Two tests were carried out to evaluate the dynamic response of rPC. The quasi-static compression test was performed on a universal machine. The dynamic in a split Hopkinson pressure bar was performed with three different strain rates. The results showed that the mechanical and primary recycling adopted in this work promoted values of yield stress in compression (77 MPa) and dynamic (up to 118 MPa), close to or superior to those reported so far in the literature.

Numerical Simulation Analysis of the Effect on the One-Dimension Assumption in Different Diameter SHPB Pressure Bar by Two Kinds of Loading Waveform

2013 ◽  
Vol 787 ◽  
pp. 759-764
Author(s):  
Sheng Zhang ◽  
Xiang Hao Yang ◽  
Xin Wen Li
Keyword(s):  
Stress Wave ◽  
Split Hopkinson Pressure Bar ◽  
Simulation Analysis ◽  
Sine Wave ◽  
Stress Waves ◽  
One Dimension ◽  
Hopkinson Pressure Bar ◽  
Finite Element Software ◽  
The One ◽  
Pressure Bar

t is one of precondition of determining rock material dynamic parameters for one-dimension assumption of the elastic pressure bar. In order to analyze its effect by loading wave type, the dynamic stress was simulated with Ls-dynamic finite element software, when SHPB(Split Hopkinson Pressure Bar) pressure bar with diameter of 50 mm, 75 mm and 100 mm were impacted respectively by a cycle rectangular loading wave and half sine loading wave. The stress waves of cross section in different diameter pressure bar and the different distance with pressure bar end were compared and analyzed. The results indicated that the dispersion of stress waves was very serious and the matching ability of stress wave at different distances in pressure bar was poor when the rectangular wave was loaded. However, the dispersion of stress wave was not obvious with the increase of the diameter of pressure bar and the change of pressure bar when the half sine wave was loaded. The half sine loading wave which can strictly meet the one-dimension assumption is one of the ideal loading waveforms of the rocky heterogeneous materials.

Contributory Factors to Accurate Prediction of Rate of Stress Corrosion Cracking in Boiling Water Reactor Under Unexpected Condition During Operation: Part 3—The Effect of High Loading Rate on SCC Growth Behaviour

2010 ◽  
Author(s):  
Yuji Tanabe ◽  
Takeo Tamura ◽  
Kenji Suzuki ◽  
Jiro Kuniya ◽  
Tetsuo Shoji
Keyword(s):  
Loading Rate ◽  
Split Hopkinson Pressure Bar ◽  
Compact Tension ◽  
High Loading ◽  
Hopkinson Pressure Bar ◽  
Growth Behaviour ◽  
Dynamic Stress Intensity Factors ◽  
High Loading Rate ◽  
Split Hopkinson ◽  
Pressure Bar

The goal of the study is to reveal the effect of high loading rate on the stable SCC growth behaviour of nuclear-grade stainless steel, SUS316L. To this end, the Split-Hopkinson pressure bar (SHPB) experiments on SUS316L were performed first to establish the dynamic tensile stress-strain response at strain rates up to 700s−1. The analyses of dynamic stress intensity factors for wedge loading experiments on modified compact tension specimens during SCC test were then performed by the finite element method. The outline of the wedge loading experiments by the use of the Split-Hopkinson pressure bar is briefly mentioned in this paper as well.

Numerical Simulation of Fracture Process of Three-Point Bending Beam of Concrete Based on Modified Mazars Model

2011 ◽  
Vol 295-297 ◽  
pp. 2097-2101
Author(s):  
Ai Min Deng ◽  
Lian Meng Gou ◽  
Dao Yuan Xu
Keyword(s):  
Numerical Simulation ◽  
Failure Process ◽  
Damage Model ◽  
Maximum Load ◽  
Initiation Toughness ◽  
Concrete Fracture ◽  
Three Point Bending ◽  
Finite Element Software ◽  
Fracture Failure ◽  
Accumulation Of Damage

Taking into account the initial damage and the accumulation of damage of concrete, Mazars damage model was modified. Based on the modified Mazars damage model, combined with finite element software ANSYS, the fracture failure process of the three-point bending notched beam of concrete was simulated. The initiation load Pini and maximum load Pmax of the three-point bending beam were determined with the damage criterion, and the full relation curve of the load P versus the loading point displacement Δ of the fracture failure process of the three-point bending beam was obtained. The results show that the method of numerical simulation of concrete fracture failure process is feasible, and based on the initiation load of the crack determined by numerical simulation, the initiation toughness of the beam can be easily calculated, and the problem of calculation of the initiation toughness caused by the initiation load can not be accurately determined in the actual experiment is resolved.

Study on the Constitutive Model of SiCp/Al Composites

2016 ◽  
Vol 693 ◽  
pp. 621-628 ◽  
Author(s):  
Xi Guo Xue ◽  
Li Jing Xie ◽  
Tao Wang
Keyword(s):  
Constitutive Model ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rate Range ◽  
Hopkinson Pressure Bar ◽  
Static Compression ◽  
Split Hopkinson ◽  
Strain Stress ◽  
Pressure Bar ◽  
Quasi Static Compression

By conducting the quasi-static compression and split Hopkinson pressure bar testing,the flow strain - stress curves under strain rate range of 0.0001-1000/s and temperature range of normal-400°C of different volume fraction SiC particles reinforced metal matrix composite SiCp/6063Al were obtained. The commonly used Johnson-Cook constitutive model in metal materials was applied in this research. And on the basis of it, the influence of volume fraction to flow stress was utilized to establish the equivalent and homogeneous constitutive model.

scholarly journals Numerical Simulation of Split-Hopkinson Pressure Bar Tests for the Combined Coal-Rock by Using the Holmquist–Johnson–Cook Model and Case Analysis of Outburst

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Beijing Xie ◽  
Dongxin Chen ◽  
Hao Ding ◽  
Guangyu Wang ◽  
Zheng Yan
Keyword(s):  
Numerical Simulation ◽  
Rock Burst ◽  
Split Hopkinson Pressure Bar ◽  
Tensile Failure ◽  
Hopkinson Pressure Bar ◽  
Finite Element Software ◽  
Split Hopkinson ◽  
Coal Rock ◽  
Pressure Bar ◽  
The Impact

In the coal and rock dynamic disasters, such as the rock burst, dynamic load damage often acts simultaneously on the combined coal and rock mass. Based on the split-Hopkinson pressure bar (SHPB) test of the combined coal and rock with a bullet velocity of 4.590–8.791 m/s, the numerical model of four kinds of combined coal and rock with different sandstone-coal-sandstone ratios, including 1 : 1 : 1, 2 : 1 : 1, 1 : 1 : 2, and 1 : 2 : 1, is investigated. A finite element software (LS-DYNA) and the Holmquist–Johnson–Cook (HJC) constitutive model of rock are employed in these regards. The stress waveform, the oscillation phenomenon of stress wave, and the damage process of the specimen in the impact test of the composite coal and rock are studied. The obtained results show that the compression-shear failure is the main failure mode of the coal body and the tensile failure of the sandstone along the axial direction in the composite coal-rock specimens. Moreover, it is found that combination of coal and rock samples is mainly destroyed by the coal body, which has no correlation with the impact speed and combination mode. Finally, numerical simulation about Hongling coalmine extralarge tunnel malfunction is carried out. Obtained results showed the protruding and stress change processes of the coal seam of the tunnel exposing. It is found that the simulation results are in an excellent agreement with those from the field investigation. The present study may provide a reference for further understanding the mechanism of the coal and rock dynamic disasters, such as the rock burst.

Selecting a Suitable Specimen Shape with Low Constraint Value for Determination of Fracture Parameters of Cementitious Composites

2013 ◽  
Vol 577-578 ◽  
pp. 481-484 ◽  
Author(s):  
Stanislav Seitl ◽  
Sara Korte ◽  
Wouter de Corte ◽  
Veerle Boel ◽  
Jakub Sobek ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Building Materials ◽  
Crack Tip ◽  
Test Configuration ◽  
Three Point Bending ◽  
Finite Element Software ◽  
Splitting Test ◽  
T Stress ◽  
Low Constraint ◽  
Wedge Splitting

The stress intensity factor and the T-stress describing the near-crack-tip fields for selected specimen shapes of a test geometry based on wedge splitting and three point bending tests with several variants of boundary conditions are computed using finite element software ANSYS. The test configuration in question is expected to be a convenient alternative to classical fracture tests (especially the tensile ones) for investigation of the quasi-brittle fracture of building materials, when low constraint is requested. These specimens are investigated within the framework of two-parameter fracture mechanics; near-crack-tip stress field parameters are determined and compared with those of the wedge splitting test due to their shape similarity. The sensitivity of the values of these parameters to the boundary conditions is also shown. Suitable choice of the shape of the specimens is discussed.

scholarly journals Modeling and Design of SHPB to Characterize Brittle Materials under Compression for High Strain Rates

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2191 ◽  
Author(s):  
Tomasz Jankowiak ◽  
Alexis Rusinek ◽  
George Z. Voyiadjis
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Brittle Materials ◽  
Material Strength ◽  
Strain Rates ◽  
Analytical Prediction ◽  
Hopkinson Pressure Bar ◽  
Finite Element Software ◽  
Pressure Bar

This paper presents an analytical prediction coupled with numerical simulations of a split Hopkinson pressure bar (SHPB) that could be used during further experiments to measure the dynamic compression strength of concrete. The current study combines experimental, modeling and numerical results, permitting an inverse method by which to validate measurements. An analytical prediction is conducted to determine the waves propagation present in SHPB using a one-dimensional theory and assuming a strain rate dependence of the material strength. This method can be used by designers of new SPHB experimental setups to predict compressive strength or strain rates reached during tests, or to check the consistencies of predicted results. Numerical simulation results obtained using LS-DYNA finite element software are also presented in this paper, and are used to compare the predictions with the analytical results. This work focuses on an SPHB setup that can accurately identify the strain rate sensitivities of concrete or brittle materials.

Effect of Specimen Width on the Contact State between the Three-Point Bending Specimen and Supports in Hopkinson Bar

2011 ◽  
Vol 462-463 ◽  
pp. 553-558
Author(s):  
Chun Huan Guo ◽  
Rui Tang Liu
Keyword(s):  
Parallel Line ◽  
Critical Value ◽  
Analysis Method ◽  
Hopkinson Pressure Bar ◽  
Contact State ◽  
Three Point Bending ◽  
Specimen Width ◽  
Loss Of Contact ◽  
Pressure Bar ◽  
The Relationship

The effect of specimen width on the contact state between the three-point bending (TPB) specimen and supports has been investigated with the apparatus of Hopkinson pressure bar using the analysis method of the propagation of stress wave. The results indicate that, the time for loss of contact decreases linearly with the increase of specimen width when the specimen width is less than a critical value, and the relationship between the time for loss of contact and the specimen width shows a parallel line to the abscissa when the specimen width is greater than the critical value.

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