Measuring Nonequibiaxial Residual Stresses and Mechanical Properties Using Knoop Indentation

2018 ◽  
Vol 48 (2) ◽  
pp. 20170730
Author(s):  
A. R. Hosseinzadeh ◽  
A. H. Mahmoudi
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Knoop Indentation

Effect of the Weld Joint Configuration on Stressed Components, Residual Stresses and Mechanical Properties

2014 ◽  
Vol 56 (4) ◽  
pp. 279-284 ◽  
Author(s):  
Bekir Çevik ◽  
Alpay Özer ◽  
Yusuf Özçatalbaş
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Weld Joint ◽  
Joint Configuration

scholarly journals Mechanical properties of rotary swaged steel components

2021 ◽  
Author(s):  
Dhia Charni ◽  
Svetlana Ortmann-Ishkina ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Jérémy Epp
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Strain Curve ◽  
Dynamic Mechanical Properties ◽  
Process Conditions ◽  
Forming Process ◽  
Rotary Swaging ◽  
Surface Residual Stresses ◽  
Near Net Shape ◽  
As Stress

AbstractThe radial infeed rotary swaging is widely used as a diameter reduction forming process of axisymmetric workpieces, improving the mechanical properties with excellent near net shape forming. In the present study, rotary swaging experiments with different parameter setups were performed on steel tubes and bars under different material states and several resulting property modifications were investigated such as stress-strain curve, hardness, fatigue strength and surface residual stresses. The results show a significant work hardening induced by the rotary swaging process and an improvement in the static and dynamic mechanical properties was observed. Furthermore, the hardness distribution was homogenous in the cross section of the rotary swaged workpieces. Moreover, depending on the process conditions, different residual stresses distribution were generated along the surface.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

scholarly journals Effect of Ion Irradiation on Nanoindentation Fracture and Deformation in Silicon Carbide

JOM ◽  
2021 ◽  
Author(s):  
Alexander J. Leide ◽  
Richard I. Todd ◽  
David E. J. Armstrong
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Residual Stresses ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Compressive Residual Stresses

AbstractSilicon carbide is desirable for many nuclear applications, making it necessary to understand how it deforms after irradiation. Ion implantation combined with nanoindentation is commonly used to measure radiation-induced changes to mechanical properties; hardness and modulus can be calculated from load–displacement curves, and fracture toughness can be estimated from surface crack lengths. Further insight into indentation deformation and fracture is required to understand the observed changes to mechanical properties caused by irradiation. This paper investigates indentation deformation using high-resolution electron backscatter diffraction (HR-EBSD) and Raman spectroscopy. Significant differences exist after irradiation: fracture is suppressed by swelling-induced compressive residual stresses, and the plastically deformed region extends further from the indentation. During focused ion beam cross-sectioning, indentation cracks grow, and residual stresses are modified. The results clarify the mechanisms responsible for the modification of apparent hardness and apparent indentation toughness values caused by the compressive residual stresses in ion-implanted specimens.

Process - Property Correlation of Friction Stir Welding of Marine Grade Aluminium Alloy 5083 Using Finite Element Analysis

2021 ◽  
Vol 163 (A2) ◽  
Author(s):  
M Sahu ◽  
A Paul ◽  
S Ganguly
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Finite Element ◽  
Friction Stir Welding ◽  
Residual Stresses ◽  
Process Variables ◽  
Friction Stir ◽  
Stress Region ◽  
Longitudinal Residual Stress ◽  
Process Property

In this article, a 3D finite element based thermo-mechanical model for friction stir welding (FSW) of a marine-grade aluminium alloy 5083 is proposed. The model demonstrates the thermal evaluation and the distribution of residual stresses and strains under the variation of process variables. The temperature profile of the weld joint during the FSW process and the mechanical properties of the joints are also experimentally evaluated. The necessary calibration of the model for the correct implementation of the thermal loading, mechanical loading, and boundary conditions was performed using the experimental results. The model simulation and experimental results are analyses in view of the process-property correlation study. The residual stress was evaluated along, and across the weld, centreline referred as longitudinal and transverse residual stresses, respectively. The magnitude of longitudinal residual stress is noted 60-80% higher than that of the transverse direction. The longitudinal residual stress generated a tensile oval shaped stress region around the tool shoulder confined to a maximum distance of about 25mm from the axis of the tool along the weld line. It encompasses the weld-nugget to thermo-mechanically affected zone (TMAZ), while the parent metal region is mostly experiences the compressive residual stresses. However, the transverse residual stress region appears like wing shaped region spread out in both the advancing and retreating side of the weld and occupying approximately double the area as compared to the longitudinal residual stresses. Overall, the study revealed a corelation between the FSW process variables such as welding speed and the tool rotational speed with the residual stress and the mechanical properties of the joint.

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