scholarly journals Evaluation Method for Residual Stresses Induced by Surface Treatments of Crankshafts and Effect of These Stresses on Fatigue Strength

2020 ◽  
Vol 55 (1) ◽  
pp. 3-10
Author(s):  
Mariko Matsuda ◽  
Hitomi Adachi ◽  
Tomonori Ikegami ◽  
Tatsuhiko Kabutomori ◽  
Toshihiko Sasaki
Keyword(s):  
Fatigue Strength ◽  
Residual Stresses ◽  
Evaluation Method ◽  
Surface Treatments

Fatigue Strength of Metal / FRP Adhesive Joints Under Low Temperature

1995 ◽  
Author(s):  
Toshio Hattori ◽  
Masaaki Iwasa
Keyword(s):  
Fatigue Strength ◽  
Low Temperature ◽  
Residual Stresses ◽  
Adhesive Joint ◽  
Evaluation Method ◽  
Stress Singularity ◽  
Adhesive Joints ◽  
Strength Evaluation ◽  
Thermal Residual Stresses ◽  
Super Conducting

Abstract Fiber reinforced plastics (FRP) have the excellent thermal isolation characteristics, and are used for for cryogenic structures such as super conducting magnets. Generally these FRP materials are connected with metal structures using adhesive joint, as these FRP materials loose strength by the existence of bolt holes. In this metal/FRP adhesive joints high thermal residual stresses occur under cryogenic temperatures as the thermal expansion coefficients of both materials differ large. So, improvement of strength evaluation method of these bi-material adhesive joints under low temperature become indispensable to develop high-reliability super conducting magnet systems such as form Magnetic Levitation Liner Motor Car. In this paper we present a new fatigue strength evaluation method under high thermal residual stresses using following two stress singularity parameters K and λ at bonding edges. τ ( r ) = K / rλ Heat τ(r) is stress (MPa), r is the distance (mm) from the singular point (bonding edge), K is the intensity of stress singularity and λ is the order of stress singularity. And this evaluation method is applied to Stainless-steel/Al2O3 FRP adhesive joint models.

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.

Correlation of Residual Stresses in the Fatigue Strength of Axles

1942 ◽  
Vol 9 (2) ◽  
pp. A85-A90
Author(s):  
O. J. Horger ◽  
H. R. Neifert
Keyword(s):  
Heat Treatment ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
High Surface ◽  
Full Size ◽  
Tensile Stresses ◽  
Compressive Stresses ◽  
Actual Service

Abstract The object of this paper is to present a correlation between residual stresses, obtained by heat-treatment, with fatigue values, determined from an investigation of full-size railroad axles. The axles tested were of both solid and tubular design and represent members which could be used under a car in actual service. It was found from these tests that high axle fatigue strength is associated with high surface residual compressive stresses, and lowest axle strength values with surface residual tensile stresses.

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