scholarly journals Closure to “Discussion of ‘A Method of Making High-Speed Compression Tests on Small Copper Cylinders’” (1949, ASME J. Appl. Mech., 16, p. 98)

1949 ◽  
Vol 16 (1) ◽  
pp. 98
Author(s):  
E. T. Habib
Keyword(s):  
High Speed ◽  
Compression Tests

Failure Process of Rock Sample Observed by AE Source Locating Technique under Uniaxial Compression

2006 ◽  
Vol 324-325 ◽  
pp. 567-570
Author(s):  
Yuan Hui Li ◽  
Rui Fu Yuan ◽  
Xing Dong Zhao
Keyword(s):  
Uniaxial Compression ◽  
High Speed ◽  
Failure Process ◽  
Compression Tests ◽  
Temporal And Spatial Distribution ◽  
Primary Stage ◽  
Brewing Process ◽  
Ae Signal ◽  
Failure Location ◽  
Low Amplitude

A series of uniaxial-compression tests were conducted on some representative brittle rock specimens, such as granite, marble and dolerite. A multi-channel, high-speed AE signal acquiring and analyzing system was employed to acquire and record the characteristics of AE events and demonstrate the temporal and spatial distribution of these events during the rupture-brewing process. The test result showed that in the primary stage, many low amplitude AE events were developed rapidly and distributed randomly throughout the entire specimens. In the second stage, the number of AE increased much slower than that in the first stage, while the amplitude of most AE events became greater. Contrarily to the primary stage, AE events clustered in the middle area of the specimen and distributed vertically conformed to the orientation of compression. The most distinct characteristic of this stage was a vacant gap formed approximately in the central part of the specimen. In the last stage, the number of AE events increased sharply and their magnitude increased accordingly. The final failure location coincidently inhabited the aforementioned gap. The main conclusion is that most macrocracks are developed from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps, and the AE activity usually becomes quite acute before the main rupture occurs.

A Short Fatigue Crack Growth Law for 1Cr18Ni9Ti Weld Metal

2006 ◽  
Vol 324-325 ◽  
pp. 571-578 ◽  
Author(s):  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Wei Hua Zhang
Keyword(s):  
High Speed ◽  
Compression Tests ◽  
Temporal And Spatial Distribution ◽  
Primary Stage ◽  
Second Stage ◽  
Final Failure ◽  
Brewing Process ◽  
Ae Signal ◽  
Failure Location ◽  
Low Amplitude

A series of uniaxial-compression tests were conducted on some representative brittle rock specimens, such as granite, marble and dolerite. A multi-channel, high-speed AE signal acquiring and analyzing system was employed to acquire and record the characteristics of AE events and demonstrate the temporal and spatial distribution of these events during the rupture-brewing process. The test result showed that in the primary stage, many low amplitude AE events were developed rapidly and distributed randomly throughout the entire specimens. In the second stage, the number of AE increased much slower than that in the first stage, while the amplitude of most AE events became greater. Contrarily to the primary stage, AE events clustered in the middle area of the specimen and distributed vertically conformed to the orientation of compression. The most distinct characteristic of this stage was a vacant gap formed approximately in the central part of the specimen. In the last stage, the number of AE events increased sharply and their magnitude increased accordingly. The final failure location coincidently inhabited the aforementioned gap. The main conclusion is that most macrocracks are developed from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps, and the AE activity usually becomes quite acute before the main rupture occurs.

A Method of Making High-Speed Compression Tests on Small Copper Cylinders

1948 ◽  
Vol 15 (3) ◽  
pp. 248-255
Author(s):  
E. T. Habib
Keyword(s):  
High Speed ◽  
Underwater Explosion ◽  
Dynamic Calibration ◽  
Test Apparatus ◽  
Compression Tests ◽  
High Speeds

Abstract In mechanical gages used to measure the pressure from an underwater explosion, small copper cylinders are compressed at high speeds. This paper describes the test apparatus designed for the dynamic calibration of these cylinders, presents the results obtained with this apparatus, and compares these results with those obtained by other experimenters.

scholarly journals Compression, Tension and Shear Testing of Fibrous Composite with the Split Hopkinson Bar Technique

2018 ◽  
Vol 183 ◽  
pp. 02006 ◽  
Author(s):  
Amos Gilat ◽  
Jeremy D. Seidt
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Fibrous Composite ◽  
Hopkinson Bar ◽  
Image Correlation ◽  
Compression Tests ◽  
Strain Rate Effects ◽  
Full Field ◽  
Split Hopkinson Bar ◽  
Split Hopkinson

The Split Hopkinson Bar (SHB) technique is used for high strain rate testing of T800/F3900 composite in compression, tension and shear. Digital Image Correlation (DIC) is used for measuring the full-field deformation on the surface of the specimen by using Shimadzu HPV-X2 high-speed video camera. Compression tests have been done on specimens machined from a unidirectional laminate in the 0°and 90° directions. Tensile tests were done in the 90° direction. Shear tests were done by using a notched specimen in a compression SHB apparatus. To study the effect of strain rate, quasi-static testing was also done using DIC and specimens with the same geometry as in the SHB tests. The results show that the DIC technique provides accurate strain measurements even at strains that are smaller than 1%. No strain rate effect is observed in compression in the 0° direction and significant strain rate effects are observed in compression and tension in the 90° direction, and in shear.

Experimental investigation of the quasi-static and impact tests on the energy absorption characteristics of coupler rubber buffers used in railway vehicles

2018 ◽  
Vol 233 (9) ◽  
pp. 937-950 ◽  
Author(s):  
Shuguang Yao ◽  
Zhixiang Li ◽  
Wen Ma ◽  
Ping Xu ◽  
Quanwei Che
Keyword(s):  
Energy Absorption ◽  
Impact Velocity ◽  
High Speed ◽  
Compression Tests ◽  
Static Compression ◽  
Static Tests ◽  
Impact Tests ◽  
High Speed Trains ◽  
The Impact ◽  
Absorption Characteristics

Coupler rubber buffers are widely used in high-speed trains, to dissipate the impact energy between vehicles. The rubber buffer consists of two groups of rubbers, which are pre-compressed and then installed into the frame body. This paper specifically focuses on the energy absorption characteristics of the rubber buffers. Firstly, quasi-static compression tests were carried out for one and three pairs of rubber sheets, and the relationship between the energy absorption responses, i.e. Eabn  =  n ×  Eab1, Edissn =  n ×  Ediss1, and Ean =  Ea1, was obtained. Next, a series of quasi-static tests were performed for one pair of rubber sheet to investigate the energy absorption performance with different compression ratios of the rubber buffers. Then, impact tests with five impact velocities were conducted, and the coupler knuckle was destroyed when the impact velocity was 10.807 km/h. The results of the impact tests showed that with the increase of the impact velocity, the Eab, Ediss, and Ea of the rear buffer increased significantly, but the three responses of the front buffer did not increase much. Finally, the results of the impact tests and quasi-static tests were contrastively analyzed, which showed that with the increase of the stroke, the values of Eab, Ediss, and Ea increased. However, the increasing rates of the impact tests were higher than that of the quasi-static tests. The maximum value of Ea was 68.76% in the impact tests, which was relatively a high value for the vehicle coupler buffer. The energy capacity of the rear buffer for dynamic loading was determined as 22.98 kJ.

A machining theory for predicting chip geometry, cutting forces etc. from work material properties and cutting conditions

1980 ◽  
Vol 371 (1747) ◽  
pp. 569-587 ◽  
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Cutting Speed ◽  
Carbon Steels ◽  
Cutting Conditions ◽  
Strain Rates ◽  
Compression Tests ◽  
Rate Dependent ◽  
Work Material ◽  
Flow Stress Data

An approximate machining theory is described in which account is taken of the temperature and strain-rate dependent properties of the work material. A feature of the theory is that the strain rates in the zones of intense plastic deformation in which the chip is formed and along the tool/ chip interface are determined as part of the solution. The theory is applied to make predictions for two plain carbon steels and a range of cutting conditions by using flow stress data obtained from high speed compression tests and excellent agreement is shown, for example, between predicted and experimental cutting forces. The values of tool/chip interface plastic zone thickness predicted by assuming a minimum work criterion are shown to agree well with experimental values, both experiment and theory indicating a marked decrease in thickness with increase in cutting speed. It is also shown how the temperatures and strain rates in this zone can be used to determine the conditions that cause a built-up edge to be formed on the cutting tool and good agreement is again shown with experimental results.

scholarly journals Compressive Rheological Behavior and Microstructure Evolution of a Semi-Solid CuSn10P1 Alloy at Medium Temperature and Low Strain

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 143
Author(s):  
Zhangxing Liu ◽  
Rongfeng Zhou ◽  
Wentao Xiong ◽  
Zilong He ◽  
Tao Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
High Strength ◽  
Operating Conditions ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Medium Temperature ◽  
Tin Alloys ◽  
Theoretical Contribution ◽  
Semi Solid

Copper–tin alloys are widely used in the machining and molding of sleeves, bearings, bearing housings, gears, etc. They are a material used in heavy-duty, high-speed and high-temperature situations and subject to strong friction conditions due to their high strength, high modulus of elasticity, low coefficient of friction and good wear and corrosion resistance. Although copper–tin alloys are excellent materials, a higher performance of mechanical parts is required under extreme operating conditions. Plastic deformation is an effective way to improve the overall performance of a workpiece. In this study, medium-temperature compression tests were performed on a semi-solid CuSn10P1 alloy using a Gleeble 1500D testing machine at different temperatures (350−440 °C) and strain rates (0.1−10 s−1) to obtain its medium-temperature deformation characteristics. The experimental results show that the filamentary deformation marks appearing during the deformation are not single twins or slip lines, but a mixture of dislocations, stacking faults and twins. Within the experimental parameters, the filamentary deformation marks increase with increasing strain and decrease with increasing temperature. Twinning subdivides the grains into lamellar sheets, and dislocation aggregates are found near the twinning boundaries. The results of this study are expected to make a theoretical contribution to the forming of copper–tin alloys in post-processing processes such as rolling and forging.

scholarly journals EXPERIMENTAL COMPRESSION TESTS OF COLD-FORMED STEEL (CFS) TO VERIFY ITS CODE-BASED STRENGTH

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Bernardo Lejano ◽  
James Matthew De Jesus ◽  
Arvin Patrick Yu
Keyword(s):  
Axial Compression ◽  
High Speed ◽  
Failure Modes ◽  
Weight Ratio ◽  
The Philippines ◽  
Structural Performance ◽  
Computational Aspect ◽  
Compression Tests ◽  
Flexural Buckling ◽  
Cold Formed Steel

Cold-Formed Steel (CFS) is a good construction material because of its high strength-to-weight ratio, that is, it exhibits efficient load carrying capabilities in combination with its lightweight characteristics. Although CFS is already being used in construction, information on structural performance of locally-produced CFS in the Philippines is scarce. To date, the authors have not found any experimental study done in the Philippines regarding the structural performance of locally-produced CFS. In this study, C-section and Z-section are being studied since these members exhibit buckling failures that may be difficult to predict due to complexity of their section geometry. The objective of this paper is to present the performance of these CFS sections when subjected to concentric axial compression both experimentally and computationally. For the experimental part, the CFS members were subjected to axial compression using a hydraulic jack. High-speed video cameras were used to capture the different failure modes. For the computational aspect, provisions found in the National Structural Code of the Philippines (NSCP) were used to calculate the compression strength of the members. A total of 80 C-section specimens with 5 different lengths and 5 different thicknesses were tested. It was found that the strength calculations using the NSCP provisions were not consistent with the results of the compression tests. For shorter lengths, distortional buckling prevailed as the main failure, while for longer lengths, torsional-flexural buckling occurred. All of the predicted strengths were highly conservative. For the Z-section, a total of 180 specimens with 6 different lengths and 6 different thicknesses were tested. Torsional-flexural buckling was observed in majority of the specimens. Although most of the failure modes were predicted correctly, it was found that the predicted strengths using the NSCP were relatively high compared to the experimental results, thus non-conservative. Finite Element Method (FEM) analyses using ANSYS were conducted. Findings indicate that the experiment results agreed well with the FEM results.

Numerical Modelling of AlSi7 Tubular Components Flowformed at Elevated Temperature

2016 ◽  
Vol 716 ◽  
pp. 753-761 ◽  
Author(s):  
Michele Francesco Novella ◽  
Andrea Ghiotti ◽  
Stefania Bruschi ◽  
Riccardo Capuzzo
Keyword(s):  
Elevated Temperature ◽  
High Speed ◽  
Limiting Factor ◽  
Main Process ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Compression Tests ◽  
Strain Paths ◽  
Constitutive Parameters ◽  
Tubular Components

In small batch manufacturing, flowforming may represent an optimal semi-finishing process for axisymmetric parts, due to its versatility, the reduced material waste, the good geometrical tolerances as well as the improvement of the mechanical characteristics it allows to attain. However, the main limiting factor often lies in the lack of knowledge for the process design, which implies expensive industrial trials often based on trial-and-error approaches. Due to these reasons Finite Element (FE) numerical simulation can provide a significant help in the design and management of the process, but its application is still facing relevant issues, mainly linked to: (i) the complex contact conditions between tooling and part, (ii) the high computation effort due to the 3D geometry rotating at high speed, and (iii) the complex strain paths that the material undergoes.The paper presents an optimized FE model of the flowforming process of AlSi7 alloy tubular components carried out at elevated temperature. An implicit solution scheme and an arbitrary Lagrangian-Eulerian meshing was adopted, while the constitutive parameters of the material model were calibrated on the basis of experimental compression tests carried out in the same thermo-mechanical conditions of the industrial reference process. The influence of the main process parameters, namely thickness reduction, feed rate and mandrel rotation speed were investigated and an algorithm for parametric process charts derivation was finally proposed.

Stress-Strain Characteristics of Various Steels over a Wide Range of Strain-Rates and Temperatures

1973 ◽  
Vol 187 (1) ◽  
pp. 523-533 ◽  
Author(s):  
T. A. Dean ◽  
C. E. N. Sturgess
Keyword(s):  
High Speed ◽  
Strain Rates ◽  
Metal Working ◽  
Compression Tests ◽  
Stress Strain ◽  
Wide Range ◽  
Mechanical Press

Compression tests are described to determine the flow stresses of steel of specifications: En 1A, En 8, En 26, En 30B, En 58 and 6:5:2 and 18:4:1 high-speed steels, which are presented for use in the analysis of metal working operations. Testing temperatures of 600°C, 800°C, 1000°C and 1200°C were employed and using each of two high-speed hammers and a mechanical press, strain-rates ranging from approximately 12/s to 2500/s were obtained.

Sign in / Sign up

Export Citation Format

Share Document