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Mechanical Behavior of Materials
Published in Snehanshu Pal, Bankim Chandra Ray, Molecular Dynamics Simulation of Nanostructured Materials, 2020
Snehanshu Pal, Bankim Chandra Ray
Plastic deformation begins under uniaxial tensile testing when the stress reaches the yield stress. The point at which dislocations depart the grain/crystal, causing plastic deformation, is also an indication for the beginning of yielding. In simple manner, the stress at which material changes its shape is known as the yield stress. The relation between the yield stresses corresponding to temperature as well as strain rate for low carbon steel specimens is shown in Figure 2.13. Slip is a thermally activated process, and thus, a raise in temperature leads to a decrease in flow stress. The rise in material strength is generally consistent with the increase in strain rate, while on the other hand, an increase in the deformation temperature causes yield strength to decrease. The yield strength increases corresponding to an increase in strain rate [10].
Mechanical Properties of Metals
Published in Zainul Huda, Metallurgy for Physicists and Engineers, 2020
The tensile test is conducted by use of a tensile testing machine. In tensile testing, the specimen is gripped in place by holding jaws (see Figure 8.4). One end of the specimen is held firm, while a hydraulic piston forces the other grip away from it thereby increasing the tensile load within the specimen. In modern machines, an electronic device for measuring the specimen extension (extensometer) is mounted on the specimen; which has to be removed once the specimen approaches its proportional limit or it will be damaged when the specimen breaks. Following the failure of the material, the specimen is reassembled; and the gauge length at failure (lf), and the final cross-sectional area (Af) are measured. The force and elongation data recorded during the tensile test are used to calculate stress, strain, strength, and ductility (see Equations 8.1–8.9).
Materials and the Sources of Stresses
Published in Neville W. Sachs, Practical Plant Failure Analysis, 2019
Photo 3.1 shows a miniature tensile test specimen that was cut from a failed piece of equipment and was used to determine the actual properties of the steel. Tensile testing can determine the strengths and the elongation of the material. In the tensile testing machine, the jaws are locked onto the test piece and the sample is slowly and steadily stressed in tension. The yield strength is determined by the applied stress when the separation between the two jaws has increased by 0.2%. The tensile strength is determined when the piece actually fractures and measuring the change in distance between two gage points on the bar after the fracture shows the elongation.
Optimization of gas tungsten arc welding parameters for welding of super duplex stainless steel using factorial design
Published in Cogent Engineering, 2023
Francis Davis, Prince Yaw Andoh, Yesuenyeagbe A. K Fiagbe, Albert Kweku Atsu
The tensile testing procedure involves a mechanical test in which a tensile force is applied to both ends of a material specimen. This test is used to determine a material’s tensile strength and other tensile properties. Tensile tests were conducted at room temperature utilizing the tensile testing instrument, interfaced with a computer software. The specimen to be tested is held between the machine’s two crossheads as depicted in Figure 2. The wedge grip type that is selected is dependent on the material’s geometry and dimensions. The force is gradually increased, and the specimen elongates during the testing process. It is repeated until the specimen fractures. The applied crosshead speed and the initial strain rate were set to 5 mm/min and 0.1/min, respectively, on the computer to determine the specimens’ extension during testing. The resulting ultimate tensile strength and yield strength are determined and recorded. The procedure is repeated for the remaining 15 specimens which are selected at random to avoid bias.
Cotton fibre elongation: a review
Published in The Journal of The Textile Institute, 2022
C. D. Delhom, J. D. Wanjura, E. F. Hequet
Tensile properties of materials are characterized through tensile testing. Tensile testing involves the application of a load on the material and monitoring the elongation of the material and recording the load at which the material either yields or fails. Elastic materials will have a yield strength above which permanent deformation of the material occurs, whereas ultimate strength is where fracture occurs. Cotton is a brittle material, as it does not yield but merely fails after reaching its maximum loading, meaning that the only strength property is ultimate strength.
Tensile strength and elongation of selected Kenaf fibres of Ghana
Published in Cogent Engineering, 2023
George Ansong, Yesuenyeagbe A.K. Fiagbe, Antonia Y. Tetteh, Francis Davis
Tensile testing is a procedure performed to estimate and provides details of the tensile mechanical properties of a material. These properties can be plotted on a graph as a stress–strain curve to show details such as the point at which the material failed. Figure 4 is the sample stress—strain plotted result of the EN31 fibre genotype.