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Recently, a biaxial test method comprising a cruciform specimen design and spatio-temporal method to determine the limit strains has been proposed for the determination of forming limit curves (FLCs) and fracture forming limit curves (FFLCs) for sheet metals. However, this test method has not yet been validated against the existing standard methods. In the present work, this biaxial test method has been applied to the aluminium alloy AA5754 for formability evaluation at room temperature and results from the biaxial test method have been compared with those from the standard Nakajima method. Theoretical analysis has been carried out to compare equi-biaxial tension cases for the two methods; a similar variation of thickness strain with radial distance normalised by the radius of the gauge area is found between the two methods. In the biaxial tests, decreasing the radius of the through-thickness dome profile, with which the gauge area is thinned, leads to fracture nearer the specimen centre but produces a less uniform strain distribution. Importantly, the major strains at necking on the FLC, as determined using the biaxial and the standard test methods, are almost the same in the plane-strain state, while in other strain states, the major strains are slightly lower for the biaxial method than that for the Nakajima method. An FFLC for AA5754 has also been determined using the biaxial test method, in which the major strain at fracture decreases with increasing strain ratio β from −0.5 to 0, while it changes only slightly when β > 0.
Ruiqiang Zhang; Zhusheng Shi; Zhutao Shao; Victoria A. Yardley; Jianguo Lin; Trevor A. Dean. Biaxial test method for determination of FLCs and FFLCs for sheet metals: validation against standard Nakajima method. International Journal of Mechanical Sciences 2021, 209, 106694 .
AMA StyleRuiqiang Zhang, Zhusheng Shi, Zhutao Shao, Victoria A. Yardley, Jianguo Lin, Trevor A. Dean. Biaxial test method for determination of FLCs and FFLCs for sheet metals: validation against standard Nakajima method. International Journal of Mechanical Sciences. 2021; 209 ():106694.
Chicago/Turabian StyleRuiqiang Zhang; Zhusheng Shi; Zhutao Shao; Victoria A. Yardley; Jianguo Lin; Trevor A. Dean. 2021. "Biaxial test method for determination of FLCs and FFLCs for sheet metals: validation against standard Nakajima method." International Journal of Mechanical Sciences 209, no. : 106694.
Stress-relaxation age forming (SRAF) of a component (820 × 300 × 3 \({\mathrm{mm}}^{3}\)) with complex and large curvatures has been simulated and a corresponding SRAF test of an Al–Mg–Si alloy, AA6082-T6, has been carried out in this study. An FE model is established to simulate the stress-relaxation ageing (SRA) behaviour of AA6082-T6 during SRAF at various stress levels, ranging from elastic to plastic regions, and a unified constitutive model for SRA of the material has been implemented in the finite element (FE) software ABAQUS via the user-defined subroutine CREEP. An optimised tool surface was determined from the FE simulation through springback predication and compensation and was used for manufacturing test. A good agreement of the formed shape has been achieved between the FE simulation and the SRAF test, with a maximum shape error below 4 mm, satisfying the industrial requirement. The hardness results from the formed plate showed an insignificant change of strength during SRAF, and are in good agreement with the simulation. The effects of the initial plastic strain and creep strain generated during loading and stress-relaxation stages on the formed shape have also been analysed.
Qi Rong; Zhusheng Shi; Yong Li; Jianguo Lin. Stress-Relaxation Age Forming of a Component with Complex and Large Curvatures: Simulation and Manufacturing. Forming the Future 2021, 921 -934.
AMA StyleQi Rong, Zhusheng Shi, Yong Li, Jianguo Lin. Stress-Relaxation Age Forming of a Component with Complex and Large Curvatures: Simulation and Manufacturing. Forming the Future. 2021; ():921-934.
Chicago/Turabian StyleQi Rong; Zhusheng Shi; Yong Li; Jianguo Lin. 2021. "Stress-Relaxation Age Forming of a Component with Complex and Large Curvatures: Simulation and Manufacturing." Forming the Future , no. : 921-934.
In this study, the austenite transformation behaviour in a medium-Mn (MMn) steel is investigated during heat treatments that replicate those occurring in low-temperature hot stamping (LTHS), with the aim of better understanding this behaviour to optimise heat-treatment design. The austenitisation behaviour and critical phase transformation temperatures during the LTHS heating process and their dependence on heating conditions are investigated using dilatometry with a Gleeble 3800 thermal-mechanical simulator, covering heating rates of 1–25 °C s−1 and soaking temperatures of 630–900 °C. Both a higher heating rate and higher soaking temperature are found to be beneficial to shorten the time required for obtaining a given austenite fraction. The martensite start temperature (Ms) shows a rapid increase with increasing soaking temperatures when austenitisation is partial, and a slower increase after full austenitisation. Excellent ultimate tensile strength values of around 1750 MPa and total elongation values of around 9.3 % are obtained for the material after the LTHS heating process. A physically based model describing the austenitic transformation under these conditions has been adopted and calibrated. The model shows good agreement with austenitic transformation diagrams constructed from experimental data, and thus can function as a guide for selecting optimum heat-treatment parameters for LTHS.
Chenpeng Tong; Guosen Zhu; Qi Rong; Victoria A. Yardley; Zhusheng Shi; Xuetao Li; Jiaming Luo; Jianguo Lin. Investigation of austenitising behaviour of medium-Mn steel in the hot-stamping heating process. Journal of Materials Processing Technology 2021, 297, 117269 .
AMA StyleChenpeng Tong, Guosen Zhu, Qi Rong, Victoria A. Yardley, Zhusheng Shi, Xuetao Li, Jiaming Luo, Jianguo Lin. Investigation of austenitising behaviour of medium-Mn steel in the hot-stamping heating process. Journal of Materials Processing Technology. 2021; 297 ():117269.
Chicago/Turabian StyleChenpeng Tong; Guosen Zhu; Qi Rong; Victoria A. Yardley; Zhusheng Shi; Xuetao Li; Jiaming Luo; Jianguo Lin. 2021. "Investigation of austenitising behaviour of medium-Mn steel in the hot-stamping heating process." Journal of Materials Processing Technology 297, no. : 117269.
A new method has been proposed in this study for the elastic-plastic buckling analysis of stiffened panels under global bending. In this method, a simplified model of the stiffened panels has been built with the application of two theories of plasticity, the incremental theory (IT) and the deformation theory (DT). The effect of transverse shear deformation through the stiffener thickness has been considered using the Mindlin-Reissner plate theory. The governing differential equations have been solved by the differential quadrature (DQ) method and an iteration process has been adopted due to the non-linearity of material properties in the elastic-plastic buckling analysis. Non-linear finite element (FE) modelling of elastic-plastic buckling analysis has been carried out, and the FE results are between those based on DT and IT in general. When the reciprocal of strain hardening exponent mt increases to 20, the FE results are in a good agreement with DT results. Based on the proposed method and FE simulations, the effect of geometric parameters of stiffened panels (stiffener thickness to height ratio, stiffened panel length to height ratio, width to height ratio, and skin thickness to stiffener thickness ratio) on buckling behaviour in the elastic-plastic region has been investigated and discussed. The proposed method provides an efficient way for parameter optimisation in the structure design of stiffened panels for the aerospace applications.
Wenbin Zhou; Zhusheng Shi; Yong Li; Qi Rong; Yuansong Zeng; Jianguo Lin. Elastic-plastic buckling analysis of stiffened panel subjected to global bending in forming process. Aerospace Science and Technology 2021, 115, 106781 .
AMA StyleWenbin Zhou, Zhusheng Shi, Yong Li, Qi Rong, Yuansong Zeng, Jianguo Lin. Elastic-plastic buckling analysis of stiffened panel subjected to global bending in forming process. Aerospace Science and Technology. 2021; 115 ():106781.
Chicago/Turabian StyleWenbin Zhou; Zhusheng Shi; Yong Li; Qi Rong; Yuansong Zeng; Jianguo Lin. 2021. "Elastic-plastic buckling analysis of stiffened panel subjected to global bending in forming process." Aerospace Science and Technology 115, no. : 106781.
A novel process for fabricating cross-sectional shapes of curved profiles in industrial applications, two-billet differential velocity sideways extrusion (DVSE), is proposed in this study. The feasibility of the process is demonstrated by fabricating solid bars of the aluminium alloy AA1070 through the solid-state welding of two billets at elevated temperature. Microstructural examination has shown that the weld formed between the two billets consists of an unsound area in the dead metal zone within the die and a sound bonding area in the welding zone. Along the welding path, the effective and normal strains gradually increase while the shear strain decreases, leading to the transformation of grains from equiaxed to bamboo-like structures and increases in the hardness, average grain size, and fraction of low angle grain boundaries. The shear strength of the welded extrudate is larger than that of the material without welding. The effective strain in the welding zone is larger than that in other zones. Increasing the temperature or speed of extrusion decreases the unsound bonding area length and the shearing angle, thus improving the uniformity of distribution of the shear strain. The grain diameter is refined from ∼500 μm in the initial billet to ∼47 μm in the welding zone of the extrudate formed at 0.05 mm/s and 450 ℃. The hardness of the extrudate formed at 400 °C and 0.1 mm/s is ∼19 % larger than that of the initial billet, and is decreased by decreasing the extrusion speed or increasing the temperature.
Xiaochen Lu; Junquan Yu; Victoria A. Yardley; Hui Liu; Zhusheng Shi; Jianguo Lin. Solid-state welding and microstructural features of an aluminium alloy subjected to a novel two-billet differential velocity sideways extrusion process. Journal of Materials Processing Technology 2021, 296, 117189 .
AMA StyleXiaochen Lu, Junquan Yu, Victoria A. Yardley, Hui Liu, Zhusheng Shi, Jianguo Lin. Solid-state welding and microstructural features of an aluminium alloy subjected to a novel two-billet differential velocity sideways extrusion process. Journal of Materials Processing Technology. 2021; 296 ():117189.
Chicago/Turabian StyleXiaochen Lu; Junquan Yu; Victoria A. Yardley; Hui Liu; Zhusheng Shi; Jianguo Lin. 2021. "Solid-state welding and microstructural features of an aluminium alloy subjected to a novel two-billet differential velocity sideways extrusion process." Journal of Materials Processing Technology 296, no. : 117189.
High-resolution (HR) high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) has revealed the atomic lattice defects in different types of η precipitates in the Al–Zn–Mg–Cu aluminium alloy subjected to creep-age forming treatment (with a constant stress lower than its room-temperature yield strength during ageing). Along the zone axes of [110]Al//[21‾1‾0]η of η1 and η12, [112]Al//[21‾1‾0]η of η2 and [100]Al//[21‾1‾0]η of η13, atomic projections of (21‾1‾0)η have been investigated. In those types of η, elongated hexagonal lattice defects (labelled as Type I defects) can be found; they are apparently related to local disorder in atomic stackings. Furthermore, in η12, elongated hexagonal lattice defects with a much higher aspect ratio (labelled as Type II defects) are uniquely observed. These atomic lattice defects are presumably pertinent to the lattice accommodation in the course of creep-age forming. Additionally, in η1 and η12, the features of a Penrose tiling defect connecting with Type I defects are observed, and these complex defects obviously affect the growth direction of the precipitate, resulting in a nearly spherical morphology. Alternatively, several entirely-passed faulted layers in a new type of precipitate, η14, consequently bring about a new orientation relationship: (513‾)Al//(0001)η14 and [112]Al//[21‾1‾0]η14. Moreover, in an atomic STEM image of η14, the significant Z-contrast gradient adjacent to the transformation front of η14 elucidates the Zn/Cu diffusion from the matrix to the precipitate along {11‾1‾}Al planes at the interface.
Tsai-Fu Chung; Yo-Lun Yang; Cheng-Ling Tai; Makoto Shiojiri; Chien-Nan Hsiao; Cheng-Si Tsao; Wei-Chih Li; Zhusheng Shi; Jianguo Lin; Hsueh-Ren Chena; Jer-Ren Yang. HR-STEM investigation of atomic lattice defects in different types of η precipitates in creep-age forming Al–Zn–Mg–Cu aluminium alloy. Materials Science and Engineering: A 2021, 815, 141213 .
AMA StyleTsai-Fu Chung, Yo-Lun Yang, Cheng-Ling Tai, Makoto Shiojiri, Chien-Nan Hsiao, Cheng-Si Tsao, Wei-Chih Li, Zhusheng Shi, Jianguo Lin, Hsueh-Ren Chena, Jer-Ren Yang. HR-STEM investigation of atomic lattice defects in different types of η precipitates in creep-age forming Al–Zn–Mg–Cu aluminium alloy. Materials Science and Engineering: A. 2021; 815 ():141213.
Chicago/Turabian StyleTsai-Fu Chung; Yo-Lun Yang; Cheng-Ling Tai; Makoto Shiojiri; Chien-Nan Hsiao; Cheng-Si Tsao; Wei-Chih Li; Zhusheng Shi; Jianguo Lin; Hsueh-Ren Chena; Jer-Ren Yang. 2021. "HR-STEM investigation of atomic lattice defects in different types of η precipitates in creep-age forming Al–Zn–Mg–Cu aluminium alloy." Materials Science and Engineering: A 815, no. : 141213.
A novel constitutive model has been proposed in this study that predicts the different stress-relaxation ageing (SRA) behaviour of AA6082-T6 with elastic and plastic loading strains, extending the applications of stress-relaxation age forming (SRAF) from conventional elastically loaded panels to complex-shaped panels under plastically loaded conditions. The particular contributions of loading strain levels in elastic or plastic regions on the evolution of microstructural variables (i.e., inter-particle spacing, dislocation density, and precipitate length), yield strength and stress-relaxation behaviour during SRA process are concurrently modelled. The decreasing creep threshold stress and the increasing dislocation recovery effect from annealing with increasing initial strain in the plastic region have been proposed and introduced in the model. TEM analysis has been performed to quantify the effect of loading strain and ageing time on the evolution of β″ precipitates, and further calibrate the material model. Furthermore, the established model has been implemented into FE simulation to optimise the tool surface design of a train body panel component with complex and large curvatures, and corresponding SRAF tests have been conducted with the optimised tool surface. The maximum shape deviation from the objective shape of a component with a dimension of 820*300*3 mm3 has been controlled within 3 mm, demonstrating the feasibility of the developed material model for SRAF in industrial applications, especially for highly demanded complex-shaped components.
Qi Rong; Zhusheng Shi; Yong Li; Jianguo Lin. Constitutive modelling and its application to stress-relaxation age forming of AA6082 with elastic and plastic loadings. Journal of Materials Processing Technology 2021, 295, 117168 .
AMA StyleQi Rong, Zhusheng Shi, Yong Li, Jianguo Lin. Constitutive modelling and its application to stress-relaxation age forming of AA6082 with elastic and plastic loadings. Journal of Materials Processing Technology. 2021; 295 ():117168.
Chicago/Turabian StyleQi Rong; Zhusheng Shi; Yong Li; Jianguo Lin. 2021. "Constitutive modelling and its application to stress-relaxation age forming of AA6082 with elastic and plastic loadings." Journal of Materials Processing Technology 295, no. : 117168.
The titanium powder embedded with 2.5 vol% TiB was in-situ fabricated by gas atomization and applied for direct laser deposited (DLD) titanium matrix composites. Consistent with the network distributed boron-rich zone in composite powder, a three-dimensional (3D) in-situ ultrafine network structure, consisting of nano-TiB whiskers (TiBw), was characterized throughout the as-fabricated composite (DLDed TiB–Ti). Both the dendritic and equiaxed network, attributed to the boron-induced constitutional supercooling and subsequent nucleation and growth of primary β-Ti, existed in the composite. The addition of boron (B) had a positive effect on the equiaxial transition and grain refinement of both primary β-Ti grains and α grains. Tensile tests showed an enhancement of strength compared with conventionally fabricated homogeneous TiB–Ti composites and selective laser melted CP-Ti. Analyzing the strength mechanism of the DLDed TiB–Ti, apart from the fine-grain strengthening and load-bearing effect of TiBw, the TiB network was found to have an additional contribution to the improvement of strength. Fracture morphology and in situ tensile observation showed the role of network structure in plastic deformation limitation, crack deflection and blunting, which was mainly attributed to the ultrafine cell size and revealed the significance of network structure.
MinHan Fang; Yuanfei Han; Zhusheng Shi; Guangfa Huang; Jingwen Song; Weijie Lu. Embedding boron into Ti powder for direct laser deposited titanium matrix composite: Microstructure evolution and the role of nano-TiB network structure. Composites Part B: Engineering 2021, 211, 108683 .
AMA StyleMinHan Fang, Yuanfei Han, Zhusheng Shi, Guangfa Huang, Jingwen Song, Weijie Lu. Embedding boron into Ti powder for direct laser deposited titanium matrix composite: Microstructure evolution and the role of nano-TiB network structure. Composites Part B: Engineering. 2021; 211 ():108683.
Chicago/Turabian StyleMinHan Fang; Yuanfei Han; Zhusheng Shi; Guangfa Huang; Jingwen Song; Weijie Lu. 2021. "Embedding boron into Ti powder for direct laser deposited titanium matrix composite: Microstructure evolution and the role of nano-TiB network structure." Composites Part B: Engineering 211, no. : 108683.
Sheet metal forming technologies have been intensively studied for decades to meet the increasing demand for lightweight metal components. To surmount the springback occurring in sheet metal forming processes, numerous studies have been performed to develop compensation methods. However, for most existing methods, the development cycle is still considerably time-consumptive and demands high computational or capital cost. In this paper, a novel theory-guided regularization method for training of deep neural networks (DNNs), implanted in a learning system, is introduced to learn the intrinsic relationship between the workpiece shape after springback and the required process parameter, e.g., loading stroke, in sheet metal bending processes. By directly bridging the workpiece shape to the process parameter, issues concerning springback in the process design would be circumvented. The novel regularization method utilizes the well-recognized theories in material mechanics, Swift's law, by penalizing divergence from this law throughout the network training process. The regularization is implemented by a multi-task learning network architecture, with the learning of extra tasks regularized during training. The stress-strain curve describing the material properties and the prior knowledge used to guide learning are stored in the database and the knowledge base, respectively. One can obtain the predicted loading stroke for a new workpiece shape by importing the target geometry through the user interface. In this research, the neural models were found to outperform a traditional machine learning model, support vector regression model, in experiments with different amount of training data. Through a series of studies with varying conditions of training data structure and amount, workpiece material and applied bending processes, the theory-guided DNN has been shown to achieve superior generalization and learning consistency than the data-driven DNNs, especially when only scarce and scattered experiment data are available for training which is often the case in practice. The theory-guided DNN could also be applicable to other sheet metal forming processes. It provides an alternative method for compensating springback with significantly shorter development cycle and less capital cost and computational requirement than traditional compensation methods in sheet metal forming industry.
Shiming Liu; Yifan Xia; Zhusheng Shi; Hui Yu; Zhiqiang Li; Jianguo Lin. Deep Learning in Sheet Metal Bending With a Novel Theory-Guided Deep Neural Network. IEEE/CAA Journal of Automatica Sinica 2021, 8, 565 -581.
AMA StyleShiming Liu, Yifan Xia, Zhusheng Shi, Hui Yu, Zhiqiang Li, Jianguo Lin. Deep Learning in Sheet Metal Bending With a Novel Theory-Guided Deep Neural Network. IEEE/CAA Journal of Automatica Sinica. 2021; 8 (3):565-581.
Chicago/Turabian StyleShiming Liu; Yifan Xia; Zhusheng Shi; Hui Yu; Zhiqiang Li; Jianguo Lin. 2021. "Deep Learning in Sheet Metal Bending With a Novel Theory-Guided Deep Neural Network." IEEE/CAA Journal of Automatica Sinica 8, no. 3: 565-581.
Materials modelling plays an important role for sprinback compensation and tool surface design in creep age forming (CAF). This review aims to provide perspective on the development and trend of materials modelling for CAF of aluminium alloys. Recently proposed unified constitutive equations for creep-ageing behaviour of aluminium alloys during CAF by integrating microstructural evolution and hardening effects are reviewed. The modelling methods and developing trend to quantitively reflect the relationship between the microstructural evolutions and macro creep-ageing behaviour of materials during CAF are discussed.
Xi Wang; Yong Li; Baoguo Chen; Zhusheng Shi. Development and trend of unified mechanism-based materials modelling for creep age forming of aluminium alloys. IOP Conference Series: Materials Science and Engineering 2021, 1024, 012021 .
AMA StyleXi Wang, Yong Li, Baoguo Chen, Zhusheng Shi. Development and trend of unified mechanism-based materials modelling for creep age forming of aluminium alloys. IOP Conference Series: Materials Science and Engineering. 2021; 1024 (1):012021.
Chicago/Turabian StyleXi Wang; Yong Li; Baoguo Chen; Zhusheng Shi. 2021. "Development and trend of unified mechanism-based materials modelling for creep age forming of aluminium alloys." IOP Conference Series: Materials Science and Engineering 1024, no. 1: 012021.
Biaxial tensile testing methods using cruciform specimens have been developed in the last few decades for the determination of forming limit diagrams (FLDs) and fracture forming limit diagrams (FFLDs) for sheet metals. One of the difficulties associated with this test geometry is the lack of a widely accepted method to determine the necking and fracture strains which are necessary to construct these diagrams. In this study, a novel spatio-temporal method has been proposed for the determination of necking and fracture strains. In the method, two rectangular zones: the base zone (BZ) and the reference zone (RZ) are selected at the location where fracture initiates. The zone RZ includes the zone BZ and both zones have the same side length in the direction parallel to the necking band but different side length in the perpendicular direction. By plotting the thickness reduction within RZ against that in BZ, the onset of localised necking can be determined by finding the intersection of the two straight lines fitted separately using the data in the initial and final stages of deformation. The corresponding limit strains are then determined using the strains within the zone BZ. The method has been successfully applied to uniaxial tensile tests on AA6082 and boron steel dog-bone specimens, and to equi-biaxial tensile tests on AA5754 cruciform specimens. • Compared to widely used existing methods, the novel spatio-temporal method has greater simplicity, stability and accuracy with regard to the determination of localised necking strains. • The spatio-temporal method has good potential to become a standard method for the determination of limit strains for sheet metals.
Ruiqiang Zhang; Zhusheng Shi; Zhutao Shao; Victoria A. Yardley; Jianguo Lin. An effective method for determining necking and fracture strains of sheet metals. MethodsX 2021, 8, 101234 .
AMA StyleRuiqiang Zhang, Zhusheng Shi, Zhutao Shao, Victoria A. Yardley, Jianguo Lin. An effective method for determining necking and fracture strains of sheet metals. MethodsX. 2021; 8 ():101234.
Chicago/Turabian StyleRuiqiang Zhang; Zhusheng Shi; Zhutao Shao; Victoria A. Yardley; Jianguo Lin. 2021. "An effective method for determining necking and fracture strains of sheet metals." MethodsX 8, no. : 101234.
Additive Manufacturing (AM) processes, also known as 3D printing, enable geometrically complex parts to be produced layer by layer on the basis of three-dimensional (3D) data generated either by scanning physical objects or using design software. Compared to conventional manufacturing processes, AM offers the elimination of production steps, allowing rapid and relatively easy prototyping of physical objects from 3D model designs, and reproduction of existing objects. Over the last two decades, AM processes have become widespread for the manufacturing of complex-shaped components in numerous industrial sectors, one of their main areas of application being in the aerospace industry. This sector makes extensive use of high-strength aluminium alloys because of their high strength-to-weight and stiffness-to-weight ratios and excellent machinability. However, the applicability of AM processes to high-strength aluminium alloys is still limited by the presence of several types of non-negligible issues and defects in additively manufactured (AMed) aluminium components. Over the years, significant research efforts have been directed at minimising or eliminating these defects and thereby expanding the range of applications of AM in high-strength aluminium alloys. This paper reviews the state of the art in AM of high-strength aluminium alloys for aerospace. The focus is on defects and issues in AMed 2xxx and 7xxx series alloys and recent developments in novel hybrid AM processes to minimise or eliminate the defects.
Sadettin C. Altıparmak; Victoria A. Yardley; Zhusheng Shi; Jianguo Lin. Challenges in additive manufacturing of high-strength aluminium alloys and current developments in hybrid additive manufacturing. International Journal of Lightweight Materials and Manufacture 2020, 4, 246 -261.
AMA StyleSadettin C. Altıparmak, Victoria A. Yardley, Zhusheng Shi, Jianguo Lin. Challenges in additive manufacturing of high-strength aluminium alloys and current developments in hybrid additive manufacturing. International Journal of Lightweight Materials and Manufacture. 2020; 4 (2):246-261.
Chicago/Turabian StyleSadettin C. Altıparmak; Victoria A. Yardley; Zhusheng Shi; Jianguo Lin. 2020. "Challenges in additive manufacturing of high-strength aluminium alloys and current developments in hybrid additive manufacturing." International Journal of Lightweight Materials and Manufacture 4, no. 2: 246-261.
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.
Hongwei Zhao; Jiangjing Xi; Kailun Zheng; Zhusheng Shi; Jianguo Lin; Kamran Nikbin; Shihui Duan; Binwen Wang. A review on solid riveting techniques in aircraft assembling. Manufacturing Review 2020, 7, 40 .
AMA StyleHongwei Zhao, Jiangjing Xi, Kailun Zheng, Zhusheng Shi, Jianguo Lin, Kamran Nikbin, Shihui Duan, Binwen Wang. A review on solid riveting techniques in aircraft assembling. Manufacturing Review. 2020; 7 ():40.
Chicago/Turabian StyleHongwei Zhao; Jiangjing Xi; Kailun Zheng; Zhusheng Shi; Jianguo Lin; Kamran Nikbin; Shihui Duan; Binwen Wang. 2020. "A review on solid riveting techniques in aircraft assembling." Manufacturing Review 7, no. : 40.
Improvement of the hot stamping process is important for reducing processing costs and improving the productivity and tensile properties of final components. One major approach to this has been to conduct all or part of the process at lower temperatures. The present paper reviews the state of the art of hot stamping techniques and their applications, considering the following aspects: (1) conventional hot stamping and its advanced developments; (2) warm stamping approaches in which complete austenitisation is not attained during heating; (3) hot stamping with a lower forming temperature, i.e., low-temperature hot stamping (LTHS); (4) advanced medium-Mn steels with lower austenitisation temperatures and their applicability in LTHS. Prospects for the further development of LTHS technology and the work required to achieve this are discussed.
Chenpeng Tong; Qi Rong; Victoria A. Yardley; Xuetao Li; Jiaming Luo; Guosen Zhu; Zhusheng Shi. New Developments and Future Trends in Low-Temperature Hot Stamping Technologies: A Review. Metals 2020, 10, 1652 .
AMA StyleChenpeng Tong, Qi Rong, Victoria A. Yardley, Xuetao Li, Jiaming Luo, Guosen Zhu, Zhusheng Shi. New Developments and Future Trends in Low-Temperature Hot Stamping Technologies: A Review. Metals. 2020; 10 (12):1652.
Chicago/Turabian StyleChenpeng Tong; Qi Rong; Victoria A. Yardley; Xuetao Li; Jiaming Luo; Guosen Zhu; Zhusheng Shi. 2020. "New Developments and Future Trends in Low-Temperature Hot Stamping Technologies: A Review." Metals 10, no. 12: 1652.
Additive Manufacturing (AM) provides almost infinite design flexibility enabling the fabrication of intricate components. This study proposes a Design for AM (DfAM) method for hot stamping dies which exploits the benefit of lattice structures’ reduced thermal conductivity. The term effective cooling area of a cooling channel is introduced and is used for lattice structure integration into a hot stamping die. Four hot stamping dies with 4 different effective cooling areas were AMed using selective laser melting and subsequently tested in the hot stamping of AA7075 aluminum alloy blanks under cyclic loading conditions. Temperature evolutions, for both the blank and die, are presented with associated computed cooling rates. The analysis of the results shows that the proposed lattice structure AMed stamping dies significantly improve the cooling performance of a hot stamping die with printing times reduced by at least 12% compared to traditionally manufactured AM dies.
Dimitrios Chantzis; Xiaochuan Liu; Denis J. Politis; Zhusheng Shi; Liliang Wang. Design for additive manufacturing (DfAM) of hot stamping dies with improved cooling performance under cyclic loading conditions. Additive Manufacturing 2020, 37, 101720 .
AMA StyleDimitrios Chantzis, Xiaochuan Liu, Denis J. Politis, Zhusheng Shi, Liliang Wang. Design for additive manufacturing (DfAM) of hot stamping dies with improved cooling performance under cyclic loading conditions. Additive Manufacturing. 2020; 37 ():101720.
Chicago/Turabian StyleDimitrios Chantzis; Xiaochuan Liu; Denis J. Politis; Zhusheng Shi; Liliang Wang. 2020. "Design for additive manufacturing (DfAM) of hot stamping dies with improved cooling performance under cyclic loading conditions." Additive Manufacturing 37, no. : 101720.
Microstructural evolution during hot forming of aluminium alloys plays a critical role in both the material flow behaviour during the deformation and the post-form mechanical properties in service. This paper presents a comprehensive review on the recrystallisation mechanisms, the interrelations between microstructures and macroscopic responses, and the associated modelling methods for aluminium alloys under hot forming conditions. Particular attention is focused on dynamic recrystallisation (DRX), which occurs during hot forming. The mechanisms, key features, and conditions of occurrence (forming temperature, strain rates, etc.) during hot forming for each type of DRX type are classified. The relationships between microstructures and macroscopic responses, including the flow behaviour, the post-form strength and ductility, are summarised based on existing experimental results. Most importantly, the associated modelling work, describing the recrystallisation and the viscoplastic behaviour under hot forming conditions, is grouped into four types, to enable a clear and concise understanding of the existing quantitative micro–macro interactions, which are particularly valuable for the future development of advanced physically based multi-scale modelling work for hot-forming processes in aluminium alloys.
Jiaxin Lv; Jing-Hua Zheng; Victoria A. Yardley; Zhusheng Shi; Jianguo Lin. A Review of Microstructural Evolution and Modelling of Aluminium Alloys under Hot Forming Conditions. Metals 2020, 10, 1516 .
AMA StyleJiaxin Lv, Jing-Hua Zheng, Victoria A. Yardley, Zhusheng Shi, Jianguo Lin. A Review of Microstructural Evolution and Modelling of Aluminium Alloys under Hot Forming Conditions. Metals. 2020; 10 (11):1516.
Chicago/Turabian StyleJiaxin Lv; Jing-Hua Zheng; Victoria A. Yardley; Zhusheng Shi; Jianguo Lin. 2020. "A Review of Microstructural Evolution and Modelling of Aluminium Alloys under Hot Forming Conditions." Metals 10, no. 11: 1516.
Hot stamping technologies require new methods for evaluating formability of sheet metal under various forming conditions. Biaxial tensile testing method using a cruciform specimen has been used for the applications, but a suitable cruciform specimen design has not yet been accepted. One of the challenges in designing a specimen for formability tests is to ensure proportional equi-biaxial strain paths arise at the location of fracture initiation. In this study, after reviewing existing cruciform specimen designs, three different geometries of cruciform specimen, named Type I, Type II and Type III, were proposed. Using numerical analysis and practical experiments, fracture initiation locations and corresponding strain paths in the specimens were investigated under equi-biaxial tension. Numerical simulations were performed to optimise the dimensions of Type I specimen to achieve a relatively high strain level near the centre point of the specimen. Based on the optimised dimensions, equi-biaxial tensile tests were carried out on cruciform specimens with different geometries, and strain paths at the fracture initiation locations were compared and analysed. It was found that in all cruciform specimens, equi-biaxial strain state appears only near the centre point. In the Type I and Type II specimens, fracture never initiates near the centre point, but at a location in the fillet transition zone where major strain is higher than that at the centre point. The Type III specimens have the ability to initiate fracture near the centre point, and to produce proportional strain paths with strain ratio β close to 1 in equi-biaxial tension, 0 in plane-strain tension, and -0.5 in uniaxial tension at the locations of fracture initiation. The research provides a cruciform specimen design, Type III, which has high potential to be used for evaluating formability for sheet metal.
Ruiqiang Zhang; Zhutao Shao; Zhusheng Shi; Trevor A. Dean; Jianguo Lin. Effect of cruciform specimen design on strain paths and fracture location in equi-biaxial tension. Journal of Materials Processing Technology 2020, 289, 116932 .
AMA StyleRuiqiang Zhang, Zhutao Shao, Zhusheng Shi, Trevor A. Dean, Jianguo Lin. Effect of cruciform specimen design on strain paths and fracture location in equi-biaxial tension. Journal of Materials Processing Technology. 2020; 289 ():116932.
Chicago/Turabian StyleRuiqiang Zhang; Zhutao Shao; Zhusheng Shi; Trevor A. Dean; Jianguo Lin. 2020. "Effect of cruciform specimen design on strain paths and fracture location in equi-biaxial tension." Journal of Materials Processing Technology 289, no. : 116932.
This research is devoted to modelling the viscoplastic deformation behaviour and microstructure evolution of particle reinforced titanium matrix composites (TMCs) at hot working conditions. A series of Gleeble hot compression tests were conducted to obtain the stress-strain curves. According to the dominant mechanisms of TMCs during deformation, a set of mechanism-based constitutive equations was developed and fitted based on the experiment data. Lamellar alpha globularisation, dynamic recrystallization and damage were considered and incorporated into the constitutive equations to describe the viscoplastic flow behaviour.
Lihua Du; Zhusheng Shi; Yuanfei Han; Jie Shao; Kailun Zheng; Yong Li; Weijie Lu. Development of constitutive equations for hot working of titanium matrix composites. MATEC Web of Conferences 2020, 321, 03033 .
AMA StyleLihua Du, Zhusheng Shi, Yuanfei Han, Jie Shao, Kailun Zheng, Yong Li, Weijie Lu. Development of constitutive equations for hot working of titanium matrix composites. MATEC Web of Conferences. 2020; 321 ():03033.
Chicago/Turabian StyleLihua Du; Zhusheng Shi; Yuanfei Han; Jie Shao; Kailun Zheng; Yong Li; Weijie Lu. 2020. "Development of constitutive equations for hot working of titanium matrix composites." MATEC Web of Conferences 321, no. : 03033.
In-plane biaxial tensile test is an alternative to determine the forming limit diagram (FLD) for evaluating the formability of metal sheets, in which cruciform specimens are deformed under the plane stress condition. Given that strong dependence of an FLD on both the strain state and the strain path, it is critical to realise the deformations under various proportional strain paths in the in-plane biaxial tensile test. In this study, three different stretching modes in a previously developed planar biaxial tensile rig, called stretching model-I, stretching model-II and stretching model-III, were applied to deform one type of cruciform specimen for AA5754 under an expected strain state of the equi-biaxial tension, the plane-strain tension and the uniaxial tension, respectively. The digital image correlation (DIC) technique was adopted for strain field measurement. By analysing the ratio and the linearity of the strain paths in the different zones within the gauge area of the cruciform specimens, it was found that, by using the stretching mode-I, the equi-biaxial strain state was obtained only in the central zone, and the corresponding strain path is linear. The plane-strain states were not achieved in any zones within the gauge area by using the stretching mode-II, and the corresponding strain paths are nonlinear. By using the stretching mode-III, the fracture occurred in a zone within the gauge area where the strain state is uniaxial and the corresponding strain path is linear, while the strain state in the central zone is close to the pure shear and the strain path is nonlinear.
Ruiqiang Zhang; Zhutao Shao; Zhusheng Shi; Jianguo Lin. A study on ratio and linearity of strain path in in-plane biaxial tensile test for formability evaluation. Procedia Manufacturing 2020, 50, 584 -588.
AMA StyleRuiqiang Zhang, Zhutao Shao, Zhusheng Shi, Jianguo Lin. A study on ratio and linearity of strain path in in-plane biaxial tensile test for formability evaluation. Procedia Manufacturing. 2020; 50 ():584-588.
Chicago/Turabian StyleRuiqiang Zhang; Zhutao Shao; Zhusheng Shi; Jianguo Lin. 2020. "A study on ratio and linearity of strain path in in-plane biaxial tensile test for formability evaluation." Procedia Manufacturing 50, no. : 584-588.
Differential velocity sideway extrusion (DVSE) process is a cutting-edge technology to manufacture curved profiles with solid or hollow cross-sections. Extrusion welding is inevitable to form hollow cross-section profiles during DVSE. In the present work, two billets (AA1070) were welded into a bar in the chamber of an extrusion die through DVSE. The material flow behaviour, grain structure and its development in the extruded bar were studied. Based on material flow behaviour, the flow plane of material in the chamber of extrusion die can be divided into metal dead zone (MDZ), shearing intensive zone (SIZ), and metal flow zone (MFZ, including the welding zone). A sound weld without any bonding interface can be obtained by DVSE welding at 500 ℃ and 0.1 mm/s. Before material arrives at the exit of extrusion die, banded structures form along the metal flow direction with the increase of deformation and the mean grain size continually decreases due to dynamic recrystallisation (DRX). Grains significantly grow after exiting from the extrusion die.
Xiaochen Lu; Junquan Yu; Jianguo Lin; Zhusheng Shi. Investigation of material flow behaviour and microstructure during differential velocity sideway extrusion. Procedia Manufacturing 2020, 50, 226 -230.
AMA StyleXiaochen Lu, Junquan Yu, Jianguo Lin, Zhusheng Shi. Investigation of material flow behaviour and microstructure during differential velocity sideway extrusion. Procedia Manufacturing. 2020; 50 ():226-230.
Chicago/Turabian StyleXiaochen Lu; Junquan Yu; Jianguo Lin; Zhusheng Shi. 2020. "Investigation of material flow behaviour and microstructure during differential velocity sideway extrusion." Procedia Manufacturing 50, no. : 226-230.