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Shujun Li

Bio: Shujun Li is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Fractography & Fracture mechanics. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

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TL;DR: In this article, the authors investigated the fatigue behavior of single-lap four-riveted aluminum alloy 7050 joints by using high-frequency fatigue test and scanning electron microscope (SEM).
Abstract: The fatigue behavior of single-lap four-riveted aluminum alloy 7050 joints was investigated by using high-frequency fatigue test and scanning electron microscope (SEM). Stress distributions obtained by finite element (FE) analysis help explain the fatigue performance. The fatigue test results showed that the fatigue lives of the joints depend on cold expansion and applied cyclic loads. FE analysis and fractography indicated that the improved fatigue lives can be attributed to the reduction in maximum stress and evolution of fatigue damage at the critical location. The beneficial effects of strengthening techniques result in tearing ridges or lamellar structure on fracture surface, decrease in fatigue striations spacing, delay of fatigue crack initiation, crack deflection in fatigue crack propagation and plasticity-induced crack closure.

8 citations


Cited by
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TL;DR: In this paper , the relationship between welding quality and energy consumption was investigated by optimizing process parameters during the 2 mm thickness 6061 aluminum alloy laser welding, and the Non-dominated Sorting Genetic Algorithm-III (NSGA-III) was utilized to minimize energy consumption while maintaining good welding quality.
Abstract: Laser welding, a key and competitive technology for advanced industrial manufacturing is powered by energy. With increasing attention to energy management and environmental protection in manufacturing, reducing energy consumption is imperative. However, the traditional optimization of laser welding has been mainly focused on welding quality without considering the total energy consumption of all components. Thus, this paper researches the relationship between welding quality and energy consumption by optimizing process parameters during the 2 mm thickness 6061 aluminum alloy laser welding. Firstly, a three-factor, three-level experiment using Central Composite Design (CCD) is constructed. Secondly, Kriging models are employed to construct the models between process parameters and objectives. Finally, the Non-dominated Sorting Genetic Algorithm-III (NSGA-III) is utilized to minimize energy consumption while maintaining good welding quality. The study shows that compared to the initial scenario, optimization can reduce energy consumption while increasing welding quality.

14 citations

Journal ArticleDOI
TL;DR: In this article, the influence of squeeze force and initial fit tolerance on the fatigue property of a riveted aircraft lap joint was analyzed under six levels of fatigue loads and the results showed that an initially oversized rivet might be detrimental to fatigue-life improvement.

12 citations

Journal ArticleDOI
01 Nov 2020
TL;DR: A practical review on current practice and novel techniques of solid riveting for aircraft applications in order to obtain a thorough understanding of the underlying mechanisms of defect development to assist industrial users to find pragmatic solutions for safe life extension of components.
Abstract: Solid riveting is the most widely used joining technique in aircraft assembly, and the current key problems affecting practical application and reliable lifting are concentrated on static strength and fatigue. This paper aims to present a practical review on current practice and novel techniques of solid riveting for aircraft applications in order to obtain a thorough understanding of the underlying mechanisms of defect development to assist industrial users to find pragmatic solutions for safe life extension of components. At first, the current status of solid riveting processes is reviewed, and the key influencing factors on static/fatigue failure of riveted joints are identified. Effects of solid riveting design parameters, manufacturing parameters, residual stress, load transfer and secondary bending on static and fatigue strengths of riveted lap joints are discussed, followed by a review of the state-of-the-art solutions that deal with static/fatigue failures. Furthermore the new development in solid riveting techniques, including the use of different materials and riveting processes, is addressed. Finally, future research perspective and applications industrial riveting is presented.

11 citations

Journal ArticleDOI
Jian Wang1, Zhiyi Liu1, Song Bai1, Jing Cao1, Juangang Zhao1, Diping Zeng1 
TL;DR: In this paper, the influence of Mg content on the microstructures, tensile properties and three-point bending fatigue behavior of Al-Cu-Mg-Ag alloys was investigated.
Abstract: This paper presents an investigation on the influence of Mg content on the microstructures, tensile properties and three-point bending fatigue behavior of Al-Cu-Mg-Ag alloys. The results indicate that the alloy containing 0.70 wt.% Mg possesses lower tensile properties and higher fatigue performance compared to the one with 1.15 wt.% Mg. Increasing Mg content in Al-Cu-Mg-Ag alloys can enhance the nucleation and precipitation of Ω phase, as well as increase the volume fraction and number density of constituent particles. The investigation of the fatigue crack initiation and growth behavior of Al-Cu-Mg-Ag alloy using interrupted fatigue tests suggests that micro-cracks mainly nucleate on Al2Cu constituent particles and the fatigue life is mainly associated with the density of constituent particles.

5 citations

Journal ArticleDOI
TL;DR: In this article , the authors applied the Christopher-James-Patterson (CJP) model to experimental data obtained by digital image correlation (DIC) and found that the effective value of the CJP stress intensity factors correlated with the ΔK-da/dN curve as obtained with Scanning Electron Microscopy measurements of the depth of striations on the fracture surface.

3 citations