Fatigue Strength Of Spot Welded Joints Research Articles

Effect of Sheet Thickness on Fatigue Strength of Spot-Welded Joints

Effect of Sheet Thickness on Fatigue Strength of Spot-Welded Joints

Effect of Scatter Factors on Fatigue Strength of Spot-Welded Joints

Effect of Scatter Factors on Fatigue Strength of Spot-Welded Joints

The effects of sheet spacing on the fatigue life of spot­welded joints

While investigating the fatigue strength of spot-welded joints, the effects of sheet spacing or gap amounts between sheet joints may be considered as one of the most important parameters on the fatigue life duration of the joints. The main goal of the present work is to study the influence of sheet spacing on the fatigue life of 5083-O aluminium alloy spot welded tensile-shear joints. The amounts of sheet spacing are the average values over three measurements of photograph observation of the cut-off surfaces from the nugget centre of the spot-welded joints. The amounts of gap distances between spot weld sheet joints for three different electrode clamping force levels were 0.09mm, 0.11mm and 0.13mm, respectively. The values of notch strength reduction factors have been obtained at all levels of applied loads based on volumetric approach. The fatigue lives of spot welded joints have been obtained according to the volumetric method using the notch strength reduction factors and the available smooth S-N curve of 5083-O aluminium alloy sheets. The results based on the volumetric approach have been compared with the experimental fatigue test data and there is good agreement between numerical predictions and experimental results.

超小型試験片を用いた自動車用薄板スポット溶接継手の疲労強度に関する検討(技術OS1-3 スポット溶接部の衝撃強度・疲労強度,技術OS1 自動車の強度・剛性・疲労信頼性設計と評価)

超小型試験片を用いた自動車用薄板スポット溶接継手の疲労強度に関する検討(技術OS1-3 スポット溶接部の衝撃強度・疲労強度,技術OS1 自動車の強度・剛性・疲労信頼性設計と評価)

Influence of welding parameters on fatigue strength of spot-welded joint considering nugget size

Electrode force, welding current and time are welding parameters in determining the nugget size and the strength of spot-welded joint. The purpose of this study is, first, to evaluate the range of welding parameters under which the strength is robust and, second, to evaluate the relationship between welding parameters and the fatigue life. To achieve these purposes, two kinds of evaluations are made: ( i ) evaluation of the relationship between welding parameters and the nugget size using the heat transfer model; (ii) evaluation of the relationship between the nugget size and the fatigue strength considering the nominal stress at the nugget.

Expert System for Fatigue Design of Spot-welded Joint.

In establishing a long life fatigue design criterion and estimating the reliability of spot-welded thin sheet structure such as the automobile and train, it is necessary to estimate fatigue strength of spot-welded joint. So far, many investigators have numerically and experimentally studied on the method of systematic fatigue strength estimation for various spot-welded joint. Also considerable amount of data on the fatigue strength of spot-welded joint has been accumulated. But, it is difficult to determine the fatigue design criterion based on the existing data when fatigue design is modified. Therefore, many tests were required to determine a new criterion for modified design. Then it takes a lot of money and time. Thus, an expert system was developed to predict the fatigue design criterion including fatigue strength and fatigue life of spot-welded joint. The expert system consists of the material destination database, the spot-welding condition database and the fatigue design module. And this expert system was developed based on the knowledge base, the numerical calculation module, interface engine and user interface. It is expected that the expert system can economically provide the designer and the manufacturer with useful information on the material properties and the fatigue design criterion for a modified design.

9732973 Fatigue strength of spot-welded joints of aluminium alloy sheets with solidification cracking nugget and its improvement Jun Takagi, Nobuyuki Mori, Masao Fujimoto (Toyota Central R&D Labs, Inc.)

9732973 Fatigue strength of spot-welded joints of aluminium alloy sheets with solidification cracking nugget and its improvement Jun Takagi, Nobuyuki Mori, Masao Fujimoto (Toyota Central R&D Labs, Inc.)

Structural stress, notch stress and stress intensity factor approach for assessment of the fatigue strength of spot-welded joints: Radaj, D. Welding in the World 1990 28, (1–2), 29–39

Structural stress, notch stress and stress intensity factor approach for assessment of the fatigue strength of spot-welded joints: Radaj, D. Welding in the World 1990 28, (1–2), 29–39