scholarly journals Dynamic Response of Rock Containing Regular Sawteeth Joints under Various Loading Rates and Angles of Application

2020 ◽  
Vol 10 (15) ◽  
pp. 5204
Author(s):  
Pei-Yun Shu ◽  
Chen-Yu Lin ◽  
Hung-Hui Li ◽  
Ta-Wui Cheng ◽  
Tzuu-Hsing Ueng ◽  
...  
Keyword(s):  
Loading Rate ◽  
Split Hopkinson Pressure Bar ◽  
Peak Stress ◽  
Hopkinson Pressure Bar ◽  
Failure Type ◽  
Loading Rates ◽  
Fracture Failure ◽  
Type D ◽  
Rate Of Increase ◽  
Pressure Bar

Intact rock-like specimens and specimens that include a single planar joint or triangular sawteeth joint at various angles are prepared for split Hopkinson pressure bar (SHPB) testing at loading rates of 303.1–5233.6 GPa/s. Only results that are associated with an error (eε) of less than 20.0% are utilized in subsequent analyses. The effects of the loading rate and angle of the load applied to various joint patterns on the failure type and dynamic peak stresses/strength of the specimens are investigated. Experimental results demonstrate that failure of each specimen can be classified into the following four types, Type A: integrated with or without tiny flake-off, Type B: slide failure, Type C: fracture failure, and Type D: crushing failure. The results of statistical analysis of variance (ANOVA) indicate that the loading rate, the angles of the base plane (β), and the asperity (α) of the sawteeth joint of the specimen all affect its dynamic peak stress when fracture failure occurs. The loading rate and β are important when the slide failure occurs, and the loading rate is the sole factor that significantly influences its dynamic peak stress when the specimen is crushed to failure. The dynamic peak stress of the specimen increases with the loading rate, while the rate of increase gradually decreases. The β and α of a jointed specimen affect the location of stress concentration during loading, further influencing the dynamic peak stress of such a specimen under slide and fracture failure. When the loading rate is high and the specimen is crushed to failure, the influences of β and α disappear, and the increase of loading rate reduces the efficiency of raising the dynamic peak stress.

Dynamic Behaviors of near β-Type Ti-5Al-5Mo-5V-3Cr Titanium Alloys under High Strain Rate

2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu
Keyword(s):  
Strain Rate ◽  
Titanium Alloys ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Fracture Failure ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Dynamic Loading Conditions

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.

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.

scholarly journals Effects of annealing and specimen geometry on dynamic compression of a Zr-based bulk metallic glass

2007 ◽  
Vol 22 (2) ◽  
pp. 389-401 ◽  
Author(s):  
George Sunny ◽  
John Lewandowski ◽  
Vikas Prakash
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Split Hopkinson Pressure Bar ◽  
Peak Stress ◽  
Specimen Geometry ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Split Hopkinson ◽  
Pressure Bar

High strain-rate compression experiments were performed with a split-Hopkinson pressure bar (SHPB) at 500–4000/s on cylindrical samples of a Zr-based bulk metallic glass (LM-1) in both the fully amorphous and annealed conditions. The effects of changes to the specimen geometry (i.e., L/D ratio) and the material heat treatment [i.e., annealing versus amorphous (as-received)], on the peak stress, strain-to-failure, and failure behavior were determined with the aid of an in situ video obtained by using a high-speed digital camera in conjunction with the split-Hopkinson pressure bar (SHPB). Examination of the in situ video recordings and light optical microscopy showed that the failed samples revealed preferential failure initiating at the sample ends due to stress concentration at the sample-insert interface. A new insert design was developed using transient, elastic-plastic finite-element simulations to reduce the effects of these stress concentrations. SHPB testing, combined with in situ video, subsequently revealed that this new experimental configuration promoted failure within the gage length and away from the sample ends in the samples tested. Significant effects of specimen geometry, insert design, and annealing on the apparent values of the peak stress, strain-to-failure, and fracture behavior were exhibited.

scholarly journals Experimental Study of the Rock Mechanism under Coupled High Temperatures and Dynamic Loads

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Huaming An ◽  
Tongshuai Zeng ◽  
Zhihua Zhang ◽  
Lei Liu
Keyword(s):  
High Temperature ◽  
Rock Strength ◽  
Loading Rate ◽  
Split Hopkinson Pressure Bar ◽  
Strength Test ◽  
Dynamic Loads ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Rock Mechanism ◽  
Pressure Bar

With the development of modern society, geomaterials are widely used for infrastructure. These materials often experience dynamic loading and high temperature, which significantly influences the mechanical behaviour of the materials. This research focuses on the effects of the loading rate and high temperature on rock mass in terms of rock mechanism. A state-of-the-art review of rock mechanism under coupled dynamic loads and high temperatures is conducted first. The rock mechanism under static and dynamic loads is introduced. The marble is taken as the rock material for the test, while the split-Hopkinson pressure bar system is used to take the dynamic tests. In addition, the principles of the split-Hopkinson pressure bar are introduced to obtain the dynamic parameters. The fracture patterns of the uniaxial compressive strength test and the Brazilian tensile strength test are obtained and compared with those well documented in the literature. Some curves for the relationships among the loading rate, strain, temperature, compressive or tensile strengths are explained. It is conduced that with the increase of the loading rate, the rock strength increases, while with the increase of the temperature, the rock strength decreases.

Experiment on Mechanical Behavior of Reinforced Concrete Subjected to Impact Loading

2012 ◽  
Vol 450-451 ◽  
pp. 523-526 ◽  
Author(s):  
Hai Feng Liu ◽  
Wei Wu Yang ◽  
Jian Guo Ning
Keyword(s):  
Reinforced Concrete ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Peak Stress ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Rate Dependent ◽  
Split Hopkinson ◽  
Reinforced Steel ◽  
Pressure Bar

The dynamic compression tests of reinforced concrete with different reinforcement ratios are carried out by split Hopkinson pressure bar (SHPB). Reinforced steel bar is placed along longitudinal and transverse direction. Experimental results show that reinforced concrete is non-linear and rate-dependent. With the enhancement of strain rate, the peak stress of reinforced concrete increases correspondingly

Performance of Anchors in Concrete Controlled by Splitting Failure under Dynamic Push-In Loadings

2017 ◽  
Vol 754 ◽  
pp. 325-328
Author(s):  
Amr A. Nassr ◽  
Wael Khair-Eldeen
Keyword(s):  
Ultimate Load ◽  
Split Hopkinson Pressure Bar ◽  
Embedment Depth ◽  
Hopkinson Pressure Bar ◽  
Noticeable Effect ◽  
Loading Rates ◽  
Load Combination ◽  
Splitting Failure ◽  
Split Hopkinson ◽  
Pressure Bar

Anchors in concrete are widely used to transfer any given load combination into a concrete member. The dynamic behavior of post-installed rebar anchors has been experimentally investigated in this study. The attention was focused on anchors controlled by concrete splitting failure, the case that may occur with anchors and fastenings located close to an edge or to a corner. In this regard, Split Hopkinson Pressure Bar (SHPB) technique has been employed to test the anchorage systems under dynamic push-in loads. The effect of loading rates, concrete compressive strengths, and embedment depths on ultimate splitting load has been studied. The results showed the loading rates had a pronounced effect on the anchor ultimate loads and total absorbed energy by the anchors. Whereas the variation of concrete compressive strength influenced the ultimate load, the increase in embedment depth had no noticeable effect on ultimate load.

Effect of Surface Modification on Rice Husk (RH)/Linear Low Density Polyethylene (LLDPE) Composites under Various Loading Rates

2016 ◽  
Vol 840 ◽  
pp. 3-7 ◽  
Author(s):  
Nur Suhaili Abdul Wahab ◽  
Mohd Firdaus Omar ◽  
Hazizan Md Akil ◽  
Zainal Arifin Ahmad ◽  
N.Z. Noimam
Keyword(s):  
Surface Modification ◽  
Dynamic Loading ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Hopkinson Pressure Bar ◽  
Silane Coupling Agents ◽  
Loading Rates ◽  
Silane Coupling ◽  
Split Hopkinson ◽  
Pressure Bar

The surface modification of RH filler was carried out using silane coupling agents in order to improve the adhesion between LLDPE and RH. RH was treated using silane coupling agent at four different concentrations (1, 3, 5 and 7 %) at room temperature. In this study, both untreated and treated RH/LLDPE composites were tested under static (0.001 s-1, 0.01 s-1 and 0.1 s-1) and dynamic loading rates (650 s-1, 900 s-1 and 1100 s-1) using universal testing machine and split Hopkinson pressure bar apparatus, respectively. Results show that the 5% treated LLDPE/RH composite shows the higher ultimate compressive strength (UCS) and rigidity as compared to untreated LLDPE/RH composites under various loading rates. Overall, it is proved that the surface treatment of RH gives significant contribution towards the UCS and rigidity of LLDPE/RH composites under both static and dynamic loading rates.

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