The complicated thermal history of wire + arc additive manufacturing (WAAM) will affect the microstructure variation and mechanical properties as-deposited material. Numerial models Inconel 718 in WAAM deposition were established location-related temperature distribution analyzed. A hybrid method cold rolling was investigated its effect on texture compared to that condition. results show features repeated cycles, high heating rate low cooling rate. trough values cycles first increases then...

For a rolling bearing fault that has nonlinearity and nonstationary characteristics, it is difficult to identify the category. A clustering diagnosis method based on ensemble empirical mode decomposition (EEMD), permutation entropy (PE), linear discriminant analysis (LDA), Gath–Geva (GG) algorithm proposed. Firstly, we decompose vibration signal using EEMD, several inherent modal components are obtained. Then, values of each component calculated get feature vector, vector reduced by LDA be...

The isothermal compression tests of the 2219 Al alloy were conducted at temperature and strain rate ranges 623–773 K 0.01–10 s−1, respectively, deformed microstructures observed. flow curves obtained show that stress decreases with increase in and/or decrease rate. physically based constitutive model is applied to describe behavior during hot deformation. In this model, Young’s modulus lattice diffusion coefficient are temperature-dependent, creep exponent regarded as a variable. predicted...

Finite element (FE) analysis of welding residual stress and deformation is one the essential stages in manufacturing process mechanical structures parts. It aids reducing production cost, minimizing errors, optimizing manufactured component. This paper presents a numerical prediction induced by two-pass TIG Al 2219 plates. The FE model was developed using ABAQUS FORTRAN packages, Goldak's heat source implemented coding nonuniform distributed flux (DFLUX) user subroutine to represent...

Rolling bearing is an important part of mechanical equipment. Timely detection rolling fault one the factors to ensure safe operation In order diagnose accurately, a novel diagnosis method based on adaptive feature selection and clustering proposed. Firstly, vibration signal obtained from decomposed by ensemble empirical mode decomposition(EEMD) extract as much information possible. Feature extraction performed for each intrinsic function(IMF) component original signal, finally 240 features...

Welding is one of the essential stages in manufacturing process mechanical structures. Friction stir welding structure aluminum alloy has been used as a primary supporting member aerospace equipment. However, friction inevitably generates residual stress that promotes initiation and propagation cracks, threatening performance welded structure. Shot peening can effectively change distribution improve fatigue properties materials. In this paper, shot are performed on 2219 plates. The fields...

The inferior mechanical properties of additive-manufactured aluminum components compared to wrought material restrict their application in the aerospace industry. Hybrid additive manufacturing and hot/cold rolling were applied. Hot was achieved using flame heating, larger deformation can be with a small force cold rolling. Both hot increase hardness, hardened depth is 50% than rolled sample. maximum hardness located at position beneath surface, indicating heterogeneous distribution induced...

Aluminum alloy 7075 is one of the materials widely used in manufacture structural components by aviation industries. High precision required producing shapes such due to shape stability and dimensional accuracy being difficult maintain throughout different stages manufacturing. In this work, an experimental study effect VSR (Vibratory Stress Relief) on deformation residual stresses aluminum thin-walled presented. It was concluded that improved size material a significant level relieving...

Aeronautical thin-walled frame workpieces are usually obtained by milling aluminum alloy plates. The residual stress within the workpiece has a significant influence on deformation due to relatively low rigidity of workpiece. To accurately predict milling-induced stress, this paper describes an orthogonal experiment for 7075 at different surface depths workpiece, without initial is obtained. parameters revealed. include speed, feed per tooth, width, and cutting depth. experimental results...

Relieving the residual stress in components is essential to improve their service performance. In this study, a roll-bending process was proposed reduce quenching large-size 2219 Al alloy ring. The effect on evaluated via finite element method (FEM) combined with experiment. of radial feed quantity, friction coefficient, and roller rotational speed during analyzed. A set optimized parameters obtained. results reveal that best reduction rates circumferential axial reached 61.72% 86.24%,...

Regulation of residual stress in a component is the key to improving its service performance. A cold expansion method was proposed for reducing 7050 aluminium alloy curved frame forging after quenching. The effect on and equivalent plastic strain distribution investigated. results showed that maximum at center thickness reduced from 153 MPa 94 expansion, while it decreased 283 120 surface with highest reduction rate 86.2%. uniformity final forming region improved. gradually decreases each...

A novel three-dimensional isolation system consisting of thick rubber bearing (TNRB), disc spring (DSB), and laminated (LRB) in series combination was designed, its composition, principle, effect were comprehensively analyzed. By combining numerical examples, the whole structure method is used to compare analyze dynamic characteristics, response, structural damage large-span structures containing new systems, horizontal based on LRB, corresponding non-isolation under multi-dimensional...