Static and fatigue tests of hybrid composite-to-steel butt joints

Differences in Fatigue Strength Between Arc and Laser Hybrid Welded Joints

Journal of Ship Production ◽

10.5957/jsp.2008.24.3.139 ◽

2008 ◽

Vol 24 (03) ◽

pp. 139-146

Author(s):

H. Remes ◽

P. Varsta

Keyword(s):

Fatigue Strength ◽

Welded Joints ◽

Fatigue Tests ◽

Notch Depth ◽

Butt Joints ◽

Fatigue Design ◽

Notch Stress ◽

Notch Geometry ◽

Laser Hybrid ◽

Fatigue Endurance

This paper presents the results of fatigue tests, including tests of laser hybrid and arc welded butt joints, for two plate thicknesses, 6 and 12 mm. Pure laser welded joints were also tested. The S-N curves based on nominal stresses for the different welded joints are presented. The results were further analyzed using the notch stress approach, where the fatigue notch factors were determined from the measured geometries of the welded joints. Unexpected differences in the S-N curves based on the notch stresses were found between the laser hybrid and arc welded joints and between the laser hybrid and pure laser welded joints. The reasons for this difference were studied with the help of extensive measurements of weld notch geometries. Significant differences in the geometries were observed. Taking into account the notch geometry and the notch depth, the notch stress approach partially explains the differences between the fatigue endurance limits of the laser hybrid and arc welded joints. The applicability of the notch stress approach to the fatigue design of laser hybrid welded joints is also discussed.

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Influences of Fiber Orientation on the Progressive Damage in Glass Reinforced Hybrid Composite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.346 ◽

2005 ◽

Vol 486-487 ◽

pp. 346-349

Author(s):

Cheol Woong Kim ◽

Sam Hong Song ◽

Dong Joon Oh

Keyword(s):

Growth Rate ◽

Stress Intensity Factor ◽

Stress Intensity ◽

Hybrid Composite ◽

Fiber Orientation ◽

Fatigue Tests ◽

Stress Intensity Factor Range ◽

Progressive Damage ◽

Loading Patterns ◽

Delamination Behavior

The anisotropy of hybrid composite such as Al/GFRP laminates made it possible to control the fiber orientation according to the loading patterns. Therefore, it is important to study the fatigue and delamination behaviors of Al/GFRP laminates by fiber orientation. Al/GFRP laminates of three different fiber orientations (0°, 45°, 90°) were chosen, and the progressive delamination behavior was examined through the fatigue tests. The effects of the fiber orientation on the crack length, the fatigue life, the delamination, the crack growth rate (da/dN), and the stress intensity factor range ( ΔK) were investigated and discussed. The findings led to a conclusion that the effect of fiber orientation should not be ignored in analyzing the progressive damage of Al/GFRP laminates.

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Fatigue improvement of aluminium welds by means of deep rolling and diamond burnishing

Welding in the World ◽

10.1007/s40194-021-01212-1 ◽

2021 ◽

Author(s):

Jan Schubnell ◽

Majid Farajian

Keyword(s):

Fatigue Strength ◽

Treatment Process ◽

Potential Method ◽

Fatigue Tests ◽

Deep Rolling ◽

Butt Joints ◽

Diamond Burnishing ◽

Life Improvement ◽

Stress States ◽

Mechanical Surface

AbstractDeep rolling is an industrially widely established mechanical surface treatment process for the modification of roughness and fatigue resistance. However, the process has not been considered as a potential method for the mechanical post welded treatment of welded joints yet. Even, the potential of deep rolling for increasing the fatigue strength is comparably well-known in the case of non-welded components. Therefore, the effect of deep rolling (hydrostatic mounted tool) and diamond burnishing (mechanical mounted tool) to increase the fatigue strength of butt joints was approved in this work for aluminium alloy AlMg4,5Mn0,7 (EN AW 5083). For this purpose, fatigue tests under full tensile loading were performed in as-welded and deep rolled, burnished and ultrasonic impact treated conditions. Different residual stress states as well as work hardening states are determined in deep rolled and burnished condition. However, similar and significant fatigue life improvement was determined for both processes.

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Fretting Fatigue Failure in Friction Grip Bolted Joints

Journal of Mechanical Engineering Science ◽

10.1243/jmes_jour_1968_010_065_02 ◽

1968 ◽

Vol 10 (5) ◽

pp. 434-437 ◽

Cited By ~ 2

Author(s):

R. Spiers ◽

M. S. G. Cullimore

Keyword(s):

Fatigue Failure ◽

Fatigue Cracking ◽

Double Cover ◽

Fatigue Tests ◽

Bolted Joints ◽

Cover Plate ◽

Butt Joints ◽

Joint Geometry ◽

Cause Of Failure ◽

Fretting Damage

Fatigue tests on a large number of double cover plate butt joints showed that the cause of failure in the majority of cases was by cracks originating in an annular area of fretting damage around the bolt hole. The nature of the fretting is discussed and the variation with load amplitude of the size of the annular area is described. Several well defined patterns of fatigue cracking were observed. These are described and their associated crack origins classified and related to the joint geometry and load levels.

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Fatigue tests of notched specimens made from butt joints at steel

Fatigue & Fracture of Engineering Materials & Structures ◽

10.1111/ffe.12473 ◽

2016 ◽

Vol 39 (12) ◽

pp. 1526-1541 ◽

Cited By ~ 11

Author(s):

C. Fischer ◽

W. Fricke ◽

C. M. Rizzo

Keyword(s):

Fatigue Tests ◽

Butt Joints ◽

Notched Specimens

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Influence of Weld-Porosity Defects on Fatigue Strength of AH36 Butt Joints Used in Ship Structures

Metals ◽

10.3390/met11030444 ◽

2021 ◽

Vol 11 (3) ◽

pp. 444

Author(s):

Vincenzo Crupi ◽

Gabriella Epasto ◽

Eugenio Guglielmino ◽

Alberto Marinò

Keyword(s):

Fatigue Strength ◽

Welded Joints ◽

Stress Ratio ◽

Infrared Camera ◽

Experimental Tests ◽

Fatigue Tests ◽

Butt Joints ◽

Ship Structures ◽

Weld Porosity ◽

Porosity Defects

Experimental tests were carried out to assess the fatigue strength of four types of welded joints, made of AH36 steel and used for ship structures. The joints differ for the presence of weld defects and for the thickness value. Fatigue tests were carried out applying axial cyclic loads at a frequency of 20 Hz and at a stress ratio R = 0.5. The temperature e increment of the specimen surface was detected during the load application by means of an infrared camera. The analysis of the thermographic images allowed the assessment of both the fatigue strength of the welded joints, applying the rapid thermographic method, and the S-N curve by the energy approach. Moreover, 3D computed tomography was used for the analysis of the defective welded joints.

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Investigation on the Residual Stresses and Fatigue Performance of Riveted Single Strap Butt Joints

Materials ◽

10.3390/ma13153436 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3436

Author(s):

Jintong Liu ◽

Anan Zhao ◽

Zhenzheng Ke ◽

Zhiqiang Li ◽

Yunbo Bi

Keyword(s):

Residual Stresses ◽

Strengthening Mechanism ◽

Fatigue Tests ◽

Fatigue Performance ◽

Butt Joints ◽

Interference Fit ◽

Design And Optimization ◽

Sheet Metal Parts ◽

Aircraft Manufacturing ◽

Riveted Joints

In aircraft manufacturing, riveting is one of the most important connection ways to fasten the sheet metal parts. The riveted single strap butt joints are mainly used in the load-bearing components of the aircraft such as the fuselage and wing panels. The connection quality and fatigue performance of the riveted joints directly affect the reliability and safety of the aircraft. In this paper, under the assumption of constant temperature, the fatigue strengthening mechanism of interference-fit riveting is introduced based on elastic-plastic mechanics and fracture mechanics. On this basis, the finite element (FE) models of the riveted single strap butt joints with various strap thickness and rivet sizes/arrangements are established. The residual stresses distribution around the riveted hole is analyzed. Furthermore, the fatigue tests of the riveted single strap butt joints with cyclic loading are carried out. The experimental results verified the correctness and effectiveness of the simulation model. Finally, the conclusion is drawn that increasing rivet size and strap thickness within the allowable weight range can improve the fatigue performance of the riveted single strap butt joints. The knowledge could be used to guide the structural design and optimization of the riveted butt joints against fatigue.

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Impact of Selected FSW Process Parameters on Mechanical Properties of 6082-T6 Aluminium Alloy Butt Joints

Archives of Metallurgy and Materials ◽

10.2478/v10172-011-0106-9 ◽

2011 ◽

Vol 56 (4) ◽

pp. 965-973 ◽

Cited By ~ 8

Author(s):

K. Krasnowski ◽

P. Sędek ◽

M. Łomozik ◽

A. Pietras

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Aluminium Alloy ◽

Process Parameters ◽

Welded Joints ◽

Fatigue Tests ◽

Butt Joints ◽

Friction Stir ◽

Shoulder Geometry ◽

The Impact

Impact of Selected FSW Process Parameters on Mechanical Properties of 6082-T6 Aluminium Alloy Butt Joints In the friction stir welding (FSW) process a rotating and travelling tool equipped with a specially designed probe is slowly plunged into joined materials, plasticizes and stirs them thus forming a joint. Various geometric shapes of stirring tools make the motion of plasticized material very complex, which, in turn, translates to the structure and mechanical properties of joints. The article presents the results of tests focused on the impact of selected FSW process parameters on the mechanical properties of butt welded joints made of 6082 aluminium alloy. The tests were performed at various linear welding speeds, using singleand double-sided test joints welded with three types of stirring tools, differing in probe and shoulder geometry. The article reveals the results of mechanical and fatigue tests of the FSW joints.

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