Impact/Indentation Strength of Iceberg and Artificial Snow Ice

1988 ◽  
Vol 110 (1) ◽  
pp. 87-93 ◽  
Author(s):  
H. El-Tahan ◽  
A. S. J. Swamidas ◽  
M. Arockiasamy
Keyword(s):  
Experimental Study ◽  
Impact Strength ◽  
Uniaxial Compression ◽  
Level Surface ◽  
Strain Rates ◽  
Compression Tests ◽  
Indentation Tests ◽  
The Impact ◽  
Uniaxial Strength

The paper presents an experimental study on the indentation and the impact strengths of iceberg and artificial snow ice. Indentation and uniaxial tests were carried out under various strain rates and confining conditions. Uniaxial compression tests were carried out on cylindrical specimens. Indentation tests were carried out on confined/unconfined rectangular ice blocks through cylindrical/flat-circular indenters. For iceberg ice, the average uniaxial strength varied between 6.6 to 7.5 MPa and the indentation strength between 17.0 to 34.0 MPa, under various strain rates. Impact was achieved by dropping a steel cylindrical indenter, weighing 60.0 kg, onto the level surface of confined/unconfined ice blocks; the velocity of impact was 2.0 m/s. The maximum (average of seven values) impact strength of iceberg ice obtained was 17.35 MPa, while that of artificial snow ice was 20.54 MPa.

A comparative experimental study on the impact strength of standard and asymmetric involute spur gears

Measurement ◽  
2021 ◽  
Vol 172 ◽  
pp. 108950
Author(s):  
Onur Can Kalay ◽  
Oğuz Doğan ◽  
Tufan Gürkan Yılmaz ◽  
Celalettin Yüce ◽  
Fatih Karpat
Keyword(s):  
Experimental Study ◽  
Impact Strength ◽  
Spur Gears ◽  
The Impact

An Experimental Study of Interfacial Friction-Hot Ring Compression

1992 ◽  
Vol 114 (1) ◽  
pp. 13-18 ◽  
Author(s):  
F. Wang ◽  
J. G. Lenard
Keyword(s):  
Experimental Study ◽  
True Strain ◽  
Interfacial Friction ◽  
Strain Rates ◽  
Compression Tests ◽  
Temperature Range ◽  
Ring Compression ◽  
Constant Friction

Ring compression tests were conducted at constant true strain rates in the temperature range of 900–975°C. The constant friction shear factor, m, was determined using a calibration chart. Scaling was permitted during the experiments in which a glass based lubricant was also used. Frictional conditions were affected most by the rate of strain; increasing it led to lower values of m.

scholarly journals A Strain Rate-Dependent Damage Evolution Model for Concrete Based on Experimental Results

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Bin Xu ◽  
Xiaoyan Lei ◽  
P. Wang ◽  
Hui Song
Keyword(s):  
Strain Rate ◽  
Uniaxial Compression ◽  
Damage Evolution ◽  
Damage Model ◽  
Evolution Model ◽  
Experimental Results ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Strain ◽  
Actual Damage

There are various definitions of damage variables from the existing damage models. The calculated damage value by the current methods still could not well correspond to the actual damage value. Therefore, it is necessary to establish a damage evolution model corresponding to the actual damage evolution. In this paper, a strain rate-sensitive isotropic damage model for plain concrete is proposed to describe its nonlinear behavior. Cyclic uniaxial compression tests were conducted on concrete samples at three strain rates of 10−3s−1, 10−4s−1, and 10−5s−1, respectively, and ultrasonic wave measurements were made at specified strain values during the loading progress. A damage variable was defined using the secant and initial moduli, and concrete damage evolution was then studied using the experimental results of the cyclic uniaxial compression tests conducted at the different strain rates. A viscoelastic stress-strain relationship, which considered the proposed damage evolution model, was presented according to the principles of irreversible thermodynamics. The model results agreed well with the experiment and indicated that the proposed damage evolution model can accurately characterize the development of macroscopic mechanical weakening of concrete. A damage-coupled viscoelastic constitutive relationship of concrete was recommended. It was concluded that the model could not only characterize the stress-strain response of materials under one-dimensional compressive load but also truly reflect the degradation law of the macromechanical properties of materials. The proposed damage model will advance the understanding of the failure process of concrete materials.

Workability of ZK60A Alloy Depending on Microstructure

2012 ◽  
Vol 217-219 ◽  
pp. 373-376 ◽  
Author(s):  
K.H. Jung ◽  
Yong Bae Kim ◽  
Byung Min Ahn ◽  
Sang Mok Lee ◽  
Jong Sup Lee ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Uniaxial Compression ◽  
Microstructural Evolution ◽  
Elevated Temperatures ◽  
Electron Backscatter Diffraction ◽  
Strain Rates ◽  
Compression Tests ◽  
Electron Backscatter ◽  
Before And After ◽  
Backscatter Diffraction

In this study, the variation of workability of semi-continuously casted and extruded ZK60A magnesium alloy was investigated. To determine the deformation capability of two different billets, uniaxial compression tests were conducted at elevated temperatures and two different strain rates. In addition, the microstructural evolution was investigated using electron backscatter diffraction (EBSD) to compare the microstructure before and after the extrusion. The formability of ZK60A depending on the microstructure is discussed based on the experimental results obtained in this study, and is compared with earlier research in the literature.

A Theoretical and Experimental Study on the Dynamic Constitutive Model of Aluminum Foams

2010 ◽  
Vol 638-642 ◽  
pp. 1878-1883
Author(s):  
Ji Lin Yu ◽  
Er Heng Wang ◽  
Liu Wei Guo
Keyword(s):  
Experimental Study ◽  
Material Parameter ◽  
Aluminum Foam ◽  
Extended Model ◽  
Strain Rates ◽  
Compression Tests ◽  
Dynamic Tests ◽  
Aluminum Foams ◽  
Open Cell ◽  
Dynamic Experiments

The phenomenological constitutive framework for compressible elasto-plastic solids presented by Chen and Lu [1] is extended to the dynamic cases by assuming that the material parameter curves in the stress potential depend also on the strain rate. To check the applicability of the extended model, three types of dynamic experiments, i.e., uniaxial compression, lateral-constrained compression and side-constrained compression tests, are conducted for an open-cell aluminum foam at different strain rates. The first two types of dynamic tests are used as characteristic tests to determine the material parameter curves at different strain rates which are then used to construct the stress potential function in the model. The results show that the stress-strain curves under side-constrained compression predicted by the model are in agreement with those obtained experimentally.

scholarly journals Constitutive modeling of nonlinear strain and time dependent behaviors of ballistic gelatin at low strain rates

Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 191-196
Author(s):  
Li Liu ◽  
Chuan Ding ◽  
Qianqian Lu
Keyword(s):  
Uniaxial Compression ◽  
Simple Shear ◽  
Constitutive Modeling ◽  
Time Dependent ◽  
Strain Rates ◽  
Compression Tests ◽  
Shear Tests ◽  
Energy Potential ◽  
Nonlinear Strain ◽  
Ballistic Gelatin

The present study is concentrated in constitutive modeling of ballistic gelatin at low strain rates. The relaxation tests, simple shear tests at strain rates ranging from 0.0005/s to 1.245/s and uniaxial compression tests at engineering strain rates ranging from 0.004/s to 0.208/s are carried out, and nonlinear strain and time dependent behaviors of ballistic gelatin are observed. A visco-hyperelastic model is proposed based on the Prony series and the reduced polynomial strain energy potential. The material parameters are obtained by fitting to the data of the relaxation and simple shear tests and validated by predicting the compression stress-strain relationships in the uniaxial compression tests. The nonlinear strain and time dependent behaviors of ballistic gelatin are well captured by the model proposed.

scholarly journals Experimental Study on Acoustic Emission Characteristics of Dry and Saturated Basalt Columnar Joints under Uniaxial Compression and Tensile Damage

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Liu Gang ◽  
Xiao Fu-kun ◽  
Cheng Qian-long ◽  
Qin Tao
Keyword(s):  
Experimental Study ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Failure Modes ◽  
Compression Tests ◽  
Steady Growth ◽  
Columnar Joints ◽  
Ae Location ◽  
Location Map ◽  
Tensile Damage

An experimental study was carried out to investigate the acoustic emission (AE) characteristics of dry and saturated basalt columnar joints under uniaxial compression and tensile damage by using the TAW-2000 rock experiment system and SH-IIAE system for the whole loading. The results show that the softening coefficient of uniaxial compressive strength and the tensile strength was 0.78 and 0.68, respectively, and water increases the sample complexity and has a strong effect on its strength. The dry sample under uniaxial compression at the beginning of loading produced a large number of AE signals, and the AE signal showed steady growth as the load increased, but the sample destruction occurred during the blank period, which can be used as a precursor of instability. From the amplitude-time-energy diagram, it can be found that as amplitude increases with hit, energy decreases, which shows an obvious triangle relation. From the uniaxial compression damage AE location map, we can find that AE events exist disorderly and show scattered distribution in each area. From the failure modes and sections of tension and uniaxial compression tests, it is found that there are many layers and fissures in rock samples, which are consistent with AE location.

Study on the Mechanical Properties of Soft Rock under Dynamic Uniaxial Compression

2004 ◽  
Vol 261-263 ◽  
pp. 277-282 ◽  
Author(s):  
Hai Bo Li ◽  
Jun Ru Li ◽  
Qing Chun Zhou ◽  
Yong Qiang Liu ◽  
X. Xia
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Strain Rate ◽  
Uniaxial Compression ◽  
Hard Rock ◽  
Soft Rock ◽  
Strain Rate Effect ◽  
Strain Rates ◽  
Young’S Moduli

The present paper introduces the experimental study on soft rock (analogized with mortar)under dynamic uniaxial compression at the strain rates from 10-5 to 101s-1. It is indicated that thecompressive strength of the soft rock increase with the increasing strain rate and the rising rates are higher than that of hard rock. The Young's moduli and Poisson's ratio of the soft rock increase with the increasing strain rate, but the rising rates are less than that of compressive strength. In addition, the mechanism of the strain rate effect of the soft rock is primarily analyzed based on the SEM results.

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