bluuebunny/crossref_metadata_2025 huggingface dataset:
One health ethics: “What then must we do?”
Authors: Lindenmayer Joann M. , Kaufman Gretchen E. , Baker Liv , Coghlan Simon , Koontz Fred W. , Nieuwland Joachim , Stewart Kristin L. , Lynn William S.
Published: December 2022

One Health, as proclaimed by the United Nations Quadripartite, is “an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals, and ecosystems.” As such, it recognizes that the health of people, other animals, and nature is closely linked and interdependent. A great deal of One Health education, research, and practice is grounded in science, while ethical considerations are addressed infrequently. Yet ethical issues are inherent to each stage of One Health. They include which aspects of interdependencies to study, how to extend health and well-being beyond humans, and what trade-offs to consider when optimizing the health of people, other animals, and nature. In this article, we call for an active debate on the ethical considerations that should underpin every stage of One Health. We propose four tenets for discussion that, if adopted, could serve as springboards from which to consider how we “ought” to teach, investigate, and practice One Health.

One Health Impact Statement

While science helps us to better understand and explain how humanity’s actions affect our planet, ethics helps us evaluate those actions—past, present, and future. Working toward engaging with questions of ethics in conferences and peer-reviewed publications will help to establish guidelines for the conceptualization, design, implementation, and evaluation of One Health teaching, research, policy, and practice. Integrating ethical considerations and debate into every aspect of One Health will support a multispecies understanding of the term “One Health” and move us forward by building a common point of departure for dialogue, deliberation, and decisions inherent in One Health.
Regulation of the alveolar regenerative niche by amphiregulin-producing regulatory T cells
Authors: Kaiser Katherine A. , Loffredo Lucas F. , Santos-Alexis Kenia de los , Ringham Olivia R. , Arpaia Nicholas
Published: December 2022

Following respiratory viral infection, regeneration of the epithelial barrier is required to preserve lung function and prevent secondary infections. Lung regulatory T (Treg) cells are critical for maintaining blood oxygenation following influenza virus infection through production of the EGFR ligand amphiregulin (Areg); however, how Treg cells engage with progenitors within the alveolar niche is unknown. Here, we describe local interactions between Treg cells and an Areg-responsive population of Col14a1+EGFR+ lung mesenchymal cells that mediate type II alveolar epithelial (AT2) cell-mediated regeneration following influenza virus infection. We propose a mechanism whereby Treg cells are deployed to sites of damage and provide pro-survival cues that support mesenchymal programming of the alveolar niche. In the absence of fibroblast EGFR signaling, we observe impaired AT2 proliferation and disrupted lung remodeling following viral clearance, uncovering a crucial immune/mesenchymal/epithelial network that guides alveolar regeneration.
Study of temporal dissociation and atomic excitation rates in a flowing N2 DC discharge and post-discharge
Authors: Levaton J , Klein A N , Amorim J , Severo J H F
Published: December 2022

In this work, we experimentally and theoretically study mechanisms of molecular dissociation and atomic excitation occurring in a flowing nitrogen DC discharge and its post-discharge. A specific discharge experimental condition for the pink afterglow plasma occurrence in the post-discharge tube is analyzed. We employ optical emission spectroscopy (OES) and Langmuir probes to measure the reduced electric field (E/N), electron density (n
e), gas temperature (T
g) and N2(X1Σ+
g) vibrational temperature (T
v) in the positive column. OES was also employed in the post-discharge for measurements of relative densities of N(4S) and N(2D) atoms in the pink afterglow. Two well-established numerical kinetic models, one for the positive column and another one for the post-discharge, were used to calculate the rates of molecular dissociation and atomic excitation as a function of gas residence time in the positive column and also in the nitrogen post-discharge. We analyzed the role of 13 molecular dissociation mechanisms, and 8 atomic excitation mechanisms in the positive column and pink afterglow. Results demonstrate that the positive column dissociation processes are dominated by the direct electron impact mechanism in the earlier discharge gas residence times and that, for longer times, reactions between electronically excited states and N2(X1Σ+
g, v) vibrational states become the dominant dissociation mechanisms. It is also observed that dissociation processes occurring in the pink afterglow present relevant rates as compared to the same processes occurring in the positive column, demonstrating the high effectiveness of such processes in the post-discharge. The N(2D) and N(2P) excitation mechanisms are also examined. We observe that molecular dissociation and atomic excitation mechanisms strongly depend on the N2(X1Σ+
g) vibrational distribution function of the discharge and post-discharge.
Isotope shifts in cadmium as a sensitive probe for physics beyond the standard model
Authors: Ohayon B , Hofsäss S , Padilla-Castillo J E , Wright S C , Meijer G , Truppe S , Gibble K , Sahoo B K
Published: December 2022

Isotope shifts (ISs) of atomic energy levels are sensitive probes of nuclear structure and new physics beyond the standard model. We present an analysis of the ISs of the cadmium atom (Cd I) and singly charged cadmium ion (Cd II). ISs of the 229 nm, 326 nm, 361 nm and 480 nm lines of Cd I are measured with a variety of techniques; buffer–gas-cooled beam spectroscopy, capturing atoms in a magneto-optic-trap, and optical pumping. IS constants for the D1 and D2 lines of Cd II are calculated with high accuracy by employing analytical response relativistic coupled-cluster theory in the singles, doubles and triples approximations. Combining the calculations for Cd II with experiments, we infer IS constants for all low-lying transitions in Cd I. We benchmark existing calculations via different many-body methods against these constants. Our calculations for Cd II enable nuclear charge radii of Cd isotopes to be extracted with unprecedented accuracy. The combination of our precise calculations and measurements shows that King plots for Cd I can improve the state-of-the-art sensitivity to a new heavy boson by up to two orders of magnitude.
Two-step photoionization of barium atoms through excited

P11,3

levels in optical dense approximation
Authors: Kosarev N I
Published: December 2022

The kinetics of two-step photoionization of barium atoms through excited

P
1

1
,
3

levels was studied by numerical simulation method in the optically dense approximation. The first laser at wavelength

λ

1

=
553.5

nm (

λ

1

=
791

nm) pumps transition

S
0

1

↔

P
1

1

(

S
0

1

↔

P
1

3

). The second laser with

λ

2

=
266

nm (

λ

2

=
310

nm) ionizes atoms from the level

P
1

1

(

P
1

3

). The third probe laser with wavelength

λ

i

=
493.41

nm causes resonant fluorescence of barium ions. It is shown that the metastable

D
2

3

from the

D

1
,
2
,
3

3

triplet in barium is strongly populated through

P
1

1
,
3

levels. Therefore, the applying of the ionizing laser tuned to a continuum from this metastable

D
2

3

can yield a significant increase in the ionization efficiency. The laser-induced fluorescence method makes it possible to estimate the photoionization yield of barium ions with an error of up to 8%. The loading rate of the barium ion beam into the ion trap, obtained numerically, is consistent with the experimental data [Opt. Exp. 19(17), 16438 (2011)]. The deceleration of ultracold plasma recombination due to the heating of electrons in superelastic collisions for the characteristic times of a two-stage process is predicted.
Tuning the electronic properties of molybdenum di-sulphide monolayers via doping using first-principles calculations
Authors: Hussain Akhtar , Asif Qurat Ul Ain , Nabi Azeem Ghulam , Asim Hamayl , Rafique Hafiz Muhammad
Published: December 2022

In 2D semiconductors, doping offers an effective approach for modulating their structural and electronic properties-owing to the creation of newly formed chemical bonds and bond relaxation. By means of density functional theory (DFT), we systematically explored the electronic properties of monolayer MoS2 doped with X-atoms (X comprises of metals Li, Be, Al; metalloids B, Si; non-metals (NMs) C, N, P, O and the NM atoms belonging to halogen group (F, Cl)). The bonding nature of the host structures with the doped elements have been determined using electron localization function (ELF). Phonon spectra calculations are performed to distinguish between the dynamically stable and unstable systems. The band gap of MoS2 stands divided into smaller values in a variety of magnitude depending on the dopant site and the nature of the substituted atom. The results show that halogen non-metals exhibit n-type conduction in both the (Mo- and S-rich) environments. Thus, substitutional doping of impurity atoms belonging to different groups can successfully tune the band gap of MoS2 to the desired level for its useful applications in semiconducting electronic devices in addition to other interesting information on the nature of doping, which could be adopted to dope other 2D-TMDs to tailor their electronic and optical characteristics for more efficient electronic devices.
Lorentz-covariant sampling theory for fields
Authors: Pye Jason
Published: December 2022

Sampling theory is a discipline in communications engineering involved with the exact reconstruction of continuous signals from discrete sets of sample points. From a physics perspective, this is interesting in relation to the question of whether spacetime is continuous or discrete at the Planck scale, since in sampling theory we have functions which can be viewed as equivalently residing on a continuous or discrete space. Further, it is possible to formulate analogues of sampling which yield discreteness without disturbing underlying spacetime symmetries. In particular, there is a proposal for how this can be adapted for Minkowski spacetime. Here we will provide a detailed examination of the extension of sampling theory to this context. We will also discuss generally how spacetime symmetries manifest themselves in sampling theory, which at the surface seems in conflict with the fact that the discreteness of the sampling is not manifestly covariant. Specifically, we will show how the symmetry of a function space with a sampling property is equivalent to the existence of a family of possible sampling lattices related by the symmetry transformations.
Tracking ALMA System Temperature with Water Vapor Data at High Frequency
Authors: He Hao , Dent William R. F. , Wilson Christine
Published: December 2022

As the world-leading submillimeter telescope, the Atacama Large Millimeter/submillimeter Array observatory is now putting more focus on high-frequency observations at Band 7–10 (frequencies from 275 to 950 GHz). However, high-frequency observations often suffer from rapid variations in atmospheric opacity that directly affect the system temperature T
sys. Current observations perform discrete atmospheric calibrations (Atm-cals) every few minutes, with typically 10–20 occurring per hour for high frequency observation and each taking 30–40 s. In order to obtain more accurate flux measurements and reduce the number of atmospheric calibrations (Atm-cals), a new method to monitor T
sys continuously is proposed using existing data in the measurement set. In this work, we demonstrate the viability of using water vapor radiometer (WVR) data to track the T
sys continuously. We find a tight linear correlation between T
sys measured using the traditional method and T
sys extrapolated based on WVR data with scatter of 0.5%–3%. Although the exact form of the linear relation varies among different data sets and spectral windows, we can use a small number of discrete T
sys measurements to fit the linear relation and use this heuristic relationship to derive T
sys every 10 s. Furthermore, we successfully reproduce the observed correlation using atmospheric transmission at microwave modeling and demonstrate the viability of a more general method to directly derive the T
sys from the modeling. We apply the semi-continuous T
sys from heuristic fitting on a few data sets from Band 7 to Band 10 and compare the flux measured using these methods. We find the discrete and continuous T
sys methods give us consistent flux measurements with differences up to 5%. Furthermore, this method has significantly reduced the flux uncertainty due to T
sys variability for one data set, which has large precipitable water vapor fluctuation, from 10% to 0.7%.
Static properties and semileptonic transitions of lowest-lying double heavy baryons*
Authors: Ghalenovi Zahra , Moazzen Sorkhi Masoumeh
Published: December 2022

The static properties and semileptonic decays of ground-state doubly heavy baryons are studied in the framework of a non-relativistic quark model. Using a phenomenological potential model, we calculate the ground-state masses and magnetic moments of doubly heavy Ω and Ξ baryons. In the heavy quark limit, we introduce a simple form of the universal Isgur-Wise function used as the transition form factor and then investigate the exclusive

semileptonic decay widths and branching fractions for

baryon transitions. Our obtained results are in agreement with other theoretical predictions.
Axial chiral vortical effect in a sphere with finite size effect*
Authors: Yang Shu-Yun , Fang Ren-Hong , Hou De-Fu , Ren Hai-Cang
Published: December 2022

We investigate the axial vortical effect in a uniformly rotating sphere subject to finite size. We use the MIT boundary condition to limit the boundary of the sphere. For massless fermions inside the sphere, we obtain the exact axial vector current far from the boundary that matches the expression obtained in cylindrical coordinates in literature. On the spherical boundary, we find both the longitudinal and transverse (with respect to the rotation axis) components with magnitude depending on the colatitude angle. For massive fermions, we derive an expansion of the axial conductivity far from the boundary to all orders of mass, whose leading order term agrees with the mass correction reported in literature. We also obtain the leading order mass correction on the boundary, which is linear and stronger than the quadratic dependence far from the boundary. The qualitative implications on the phenomenology of heavy ion collisions are speculated.
Towards practical Quantum Credit Risk Analysis
Authors: Dri Emanuele , Giusto Edoardo , Aita Antonello , Montrucchio Bartolomeo
Published: December 2022

In recent years a CRA (Credit Risk Analysis) quantum algorithm with a quadratic speedup over classical analogous methods has been introduced [1]. We propose a new variant of this quantum algorithm with the intent of overcoming some of the most significant limitations (according to business domain experts) of this approach. In particular, we describe a method to implement a more realistic and complex risk model for the default probability of each portfolio’s asset, capable of taking into account multiple systemic risk factors. In addition, we present a solution to increase the flexibility of one of the model’s inputs, the Loss Given Default, removing the constraint to use integer values. This specific improvement addresses the need to use real data coming from the financial sector in order to establish fair benchmarking protocols.

Although these enhancements come at a cost in terms of circuit depth and width, they nevertheless show a path towards a more realistic software solution. Recent progress in quantum technology shows that eventually, the increase in the number and reliability of qubits will allow for useful results and meaningful scales for the financial sector, also on real quantum hardware, paving the way for a concrete quantum advantage in the field.

The paper also describes experiments conducted on simulators to test the circuit proposed and contains an assessment of the scalability of the approach presented.
Characterization of Quantum Grade Interconnects
Authors: Ferguson R , Hall S.R.G , Smith J , Pitwon R , Lee B
Published: December 2022

Quantum grade interconnects, which includes quantum grade optical fibre links and Quantum Photonic Integrated Circuits (QPICs), are rapidly developing components central to the successful development of the Quantum Internet and Quantum Key Distribution (QKD). These interconnects will present new metrological challenges that need to be addressed to ensure key support of future scientific and industrial development. Potential metrological solutions evolving alongside associated standardisation will ensure success and reliability of this advanced technology and provide key support to future scientific research and industrial manufacturing.
Continuous Variable Based Quantum Random Number Generator with Observable Assumptions
Authors: Tebyanian Hamid
Published: December 2022

This paper presents a semi-device independent protocol for quantum randomness generation constructed on the prepare-and-measure scenario based on the on-off-keying encoding scheme and homodyne and heterodyne detection schemes. Additionally, we introduce a straightforward optical implementation utilizing commercial off-the-shelf components.
Metrology Challenges in Quantum Key Distribution
Authors: Gui Y , Unnikrishnan D , Stanley M , Fatadin I
Published: December 2022

The metrology of the QKD devices and systems grows increasingly important in recent years not only because of the needs for conformance and performance testing in the standardization, but more importantly, imperfect implementation of the devices and systems or deviations from the theoretical models, which could be exploited by eavesdropper, should be carefully characterised to avoid the so-called side channel attack. In this paper, we review the recent advances in many aspects of the QKD metrology in both fibre based QKD and free space QKD systems, including a cutting edge metrology facility development and application, traceable calibration methods, and practical device characterising technologies, all of which have been contributed by the metrology communities and relative institutions.
In situ EBSD studies of the selection of stress-induced martensitic variants in NiTi alloy
Authors: Li C , Luo J , Pang H Y , Li M Q
Published: December 2022

In situ EBSD investigations were conducted to polycrystalline NiTi alloy during tensile deformation to study the variation selection of martensitic transformation and its effect on pseudoelasticity. Experiments show that more than one martensite variants are formed in most grains, and the directions of traces for some variants are close to the direction of macroscopic Lüders band. Then the Schmid factors of activated variants in each grain were calculated, the results show that Schmid factors of activated shear systems can be divided into three categories, I: maximum Schmid factor; II: sub-maximum Schmid; III: small Schmid factor. The appearance of the latter two categories is mainly influenced by constraints of neighboring grains and variety of local stress state caused by Lüders band. And the Schmid factors of residual martensites belong to the third category. It is mainly because dislocations are easily introduced at the front of the Lüders band during the transformation process, which decrease the order degree of B2 phase and increase the difficulty of reverse phase transformation, and the sample shows poor pseudoelasticity.
Improving the formability during ultrasonic-assisted multi-stage incremental sheet forming
Authors: Ghafoor S , Li Y L , Zhao G L , Li F Y
Published: December 2022

Multi-stage sheet forming is an encouraging technique to obtain complex geometries by change of the design of intermediate stages. Due to the occurrence of stepped feature during multi-stage forming, the final geometry shape is affected and the formability is deteriorated. To eliminate fracture and enhance formability, ultrasonic assistance is integrated with the multi-stage sheet forming process. The present work aims to investigate the effect of ultrasonic-vibrations (UV) on formability and thickness evolution using two multi-stage strategies through experiments. A frequency of 29 kHz and an amplitude of 10 μm are taken for the ultrasonic-assisted incremental forming process. Firstly, two distinct strategies are compared by experiments. Secondly, thorough investigation of formability experiments is performed by applying the UV at only one or two stages instead of the complete multi-stage forming process. The results show that formability of the part is increased while applying UV at intermediate stages. Similarly, it is confirmed that UV is more advantageous during latter stage of experiment. This work provides an effective strategy to improve the formability of the incremental sheet forming process by using the ultrasonic vibrations in a smart way.
Effect of solution treatment on static recrystallization of a post-deformed GH4586 superalloy
Authors: Chen K , Luo J , Yang J , Li M Q
Published: December 2022

Solution treatment was carried on a post-deformed GH4586 superalloy in the solution temperature range of 1020°C to 1100°C and solution time of 2 h and 4 h. The results showed that the static recrystallization (SRX) occurred due to the residual distortion energy caused by high temperature deformation. With increasing solution temperature from 1020°C to 1100°C, the average grain size of γ matrix firstly decreased and then increased. With increasing solution time from 2 h to 4 h, the average grain size of γ matrix gradually increased from 24.2±3.2 μm to 30.9±3.8 μm. Grain boundaries and twinning boundaries are the main nucleated site for SRX. And when solution treated at 1020°C for 2 h, carbides can also become the preferential nucleation position. In addition, by analysing the relative deviation (v/vm
) distributions of Σ3 boundaries, it could be found that the higher solution temperature would lead to the increasing fraction of coherent Σ3 boundaries and the decreasing fraction of incoherent ones. Besides, the annealing twins nucleated and grew gradually during the migration of recrystallized grain boundaries, and their length fraction increased from 10.0% to 54.9% with increasing solution temperature.
Significant analysis of the influence of process parameters on the wrinkling of aluminum alloy double-wall gap tube in rotary draw bending
Authors: Hao X C , Liu Y L , Gong F K
Published: December 2022

Aluminum alloy double-wall gap tube is prone to wrinke in the rotary draw bending because the rigidity of the inner and outer tubes of the thin-walled structure is low, the mechanical properties between the tubes and the polymer filling medium are different greatly, and the bending forming is a complex nonlinear process of multi-mold coordination and multifactor coupling. While the process parameters are the main factors that affect the wrinkling of inner and outer tube, there are many process parameters and there are interactions among them. Therefore, based on the platform of ABAQUS/Explicit, elastic-plastic 3D-FE model of double-wall gap tube’s bending is established to study the influence mechanism of process parameters on the wrinkling aluminum alloy double-wall gap tube in rotary draw bending. The results show that the clearance between mandrel and inner tube, clearance between pressure die and outer tube, the anti-wrinkle die and the outer tube have significant effects on the wrinkling of the inner tube. The clearance between inner tube and core die, filling medium and inner tube and clearance between anti-wrinkle die and outer tube have significant effects on the wrinkling of inner tube. The wrinkling of the outer tube is more obvious than that of the inner tube. The results can provide a theoretical basis for optimizing the process parameters to suppress the wrinkling of aluminum alloy double-wall gap tube in the rotary-draw bending.
Wrinkling behavior of the ultra-thin components with complex polygonal-sections during tube hydro-pressing process
Authors: Han C , Zhuang Y P
Published: December 2022

The wrinkling behavior of the ultra-thin components during the tube hydro-pressing process was investigated by finite element analysis and confirmed by hydro-pressing experiment and the causes of various typical defects were explored. There are three typical wrinkle defects appearing on the part during the tube hydro-pressing process: transverse wrinkles, longitudinal wrinkles and oblique wrinkles. The transverse wrinkles are mainly caused by compressive stress perpendicular to wrinkles. The longitudinal wrinkles are mainly caused by tensile stress parallel to wrinkles. While, the oblique wrinkles are mainly due to shear stress.
An efficient numerical integration system for stiff unified constitutive equations for metal forming applications
Authors: Dear J , Shi Z , Lin J
Published: December 2022

Unified constitutive equations have been developed in recent years to predict viscoplastic flow and microstructural evolution of metal alloys for metal forming applications. These equations can be implemented into commercial FE code, such as ABAQUS and PAMSTAMP, to predict mechanical and physical properties of materials in a wide range of metal forming processes. These equations are normally stiff and need significant computer CPU time to solve. In this research, a series of numerical analyses are performed to investigate the difficulties within MATLAB of solving these stiff unified constitutive equations. A metric is introduced to allow evaluation of the numerical stiffness to assess the most appropriate numerical integration method. This metric is based on the ratio of maximum to minimum eigenvalue. This metric allows for an appropriate numerical method to be chosen giving more effective modelling of deformation and plasticity processes. Based on the theoretical work described above, a user-friendly system, based on MATLAB, is then developed for numerically integrating these types of stiff constitutive equations. This is particularly useful for metal forming engineers and researchers who need an effective computational tool to determine constitutive properties well based on numerical integration theories.
Aluminum/steel rolled composite finite element secondary development simulation and experimental study
Authors: Gao B X , Yu C , Xiao H
Published: December 2022

Given the significant difference in the properties of the two metals, the rolled composite has a severe problem of uncoordinated deformation and low bond strength. The effect of the same diameter and different diameters of the rolls and single roll drive on the composite plate’s coordinated deformation and bond strength is investigated. Simulation modeling employs finite element (FE) secondary development, and the plate warpage mechanism is analyzed by combining synchronous and asynchronous rolling experiments. The aluminum side is subjected to compressive stresses in the rolling direction during the rolling process. The steel side is subjected to tensile stresses in the rolling direction. The roll diameter in contact with the aluminum plate is reduced, the rolling pressure is distributed more evenly along the vertical plate section direction, improving deformation coordination. The side of the roll that touches the aluminum is driven, and the bimetal starts to bond closer to the exit of the roll. The frictional stresses and bending moments between the bimetallic interface are smaller, resulting in better deformation coordination and higher bond strength.
Digitization of roll forming and its application
Authors: Ren Y , Dong J , Sun Y , Sedlmaier A , Guo Q , Zhang D , Yang J
Published: December 2022

With the rapid development of metaverse and intelligent manufacturing, the requirement for the digitization of the traditional manufacturing process is a challenging task for industries. Roll forming is a highly efficient sheet metal forming process which can be widely been applied in a wide range of sectors, such as automotive, transportation, building other key sectors. However, this forming process is highly dependent on the experience of the on-site engineers. This paper presents a highly intelligent, flexible and self-adaption roll forming machine co-developed by the University of Electronic Science and Technology of China and data M. The machine consists of several flexible moving units controlled by codded stepper motors with a decent control system. Moreover, a high-performing artificial intelligence algorithm achieved from a systematic machine learning training process is integrated into this machine. The algorithm has already been use to predict and control the forming process to achieve a high-quality product. Data collection on a large scale and integrated sensors lead to an increased understanding of the process and provide the basis to develop self-optimizing roll forming machines, increasing the productivity, quality and predictability of the roll forming process. The application of digital twin and machine learning techniques is used to predict and reduce the amount of springback in the product. The first high-strength steel parts successfully manufactured with this new forming concept are presented.
Process parameters impact on the forming quality of conical rotary parts during power spinning
Authors: Xiang Y X , Shu X D , Lu Q Y , Zheng J B , Cen Z W
Published: December 2022

The conical rotary part with variable wall thickness is a typical aircraft engine sheet metal casing, which requires high forming quality. In this paper, the hot power spinning process of conical rotary part with continuously variable wall thickness of superalloy GH4169 was simulated by DEFORM-3D FE (finite element) software. The equivalent stress, equivalent strain and temperature distribution characteristics were analysed to explore the forming mechanism. The single factor variable method was used to explore the influence of three process parameters, namely, the mandrel speed, the roller feed ratio and the spinning temperature, on the forming quality. The wall thickness deviation and the roundness error of the cone outer surface were taken as the evaluation indexes. Excessive thinning rate will produce large equivalent strain, which may lead to work piece fracture. Therefore, appropriate roller feed ratio should be selected to reduce the generation of defects. The results provide a theoretical basis for improving the service life of aero-engine sheet metal casing.
Feasibility study on straightening process of rotating bending for small and medium-sized shaft and pipe parts
Authors: Meng Q D , Zhao J , Mu Z K , Yu G C
Published: December 2022

Shaft and pipe parts are an important steel product. Due to various factors, their straightness often exceeds the standard, which seriously affects their performance and life. In view of the limitations of the existing straightening processes, this paper proposes a rotating bending straightening process. The two ends of the workpiece are clamped by the fixtures, and the bending and rotation are realized by controlling the movement of the fixtures. In the process, the workpieces undergo multiple reciprocating bending and is finally straightened. The feasibility of the process is verified by numerical simulation and experiments. The deflection of the shaft with an initial deflection of 1 mm is less than 0.1 mm after straightening. This process can improve the straightening efficiency and accuracy, and is suitable for mass straightening.
Influence of local reinforcement on the collision performance of B-pillar
Authors: Li F F , Tian H B , Lin J P
Published: December 2022

The B-pillar is one critical structural component pertinent to automobile safety under side impact. Local reinforcement is an effective approach to enhance the energy absorption capability of the B-pillar without causing excessive deformation. In this paper, impact simulation of a B-pillar part was carried out with five different strength distribution schemes, including all low strength, all high strength, upper 1/3 reinforced, upper 2/3 reinforced, and rounded corners reinforced. The amount of deformation, the absorbed energy, and the stress distribution over the B-pillar were analyzed. It is observed that local reinforcement effectively reduced the deformation of B-pillar under impact while maintaining sufficient energy absorption ability.
Experimental study on laser peen forming of aluminium alloy 2024-T351 plate
Authors: Huang X , Zeng Y S , Wang M T , Zou S K
Published: December 2022

Laser peen forming technology LPF is proposed on the basis of laser peen strengthening technology and mechanical peen forming technology. It is an advanced high-efficiency and long-life manufacturing technology for panels. This forming technology has a wide application prospect in the field of aerospace manufacturing. In the forming process, there are many factors affecting the forming process, such as laser pulse energy, shot peening times, shot peening path, material, structure and so on. At present, there are few studies on the influence of laser peen forming process parameters on the shape of parts, which can not meet the technical requirements of forming process. In this paper, based on the single curvature bending forming of al2024-T351 aluminum alloy, the elastic-plastic deformation of metal surface formed by laser shot peening is investigated. The spot morphology formed by laser shot peening is analyzed. The influence law of different forming process parameters on the forming shape of parts is established. The results show that the thickness is the main influencing factor for the curvature radius of the impact area. The radius of curvature increases with the increase of thickness, and decreases with the increase of pulse energy and coverage. Using the regression analysis method, the mathematical model of laser peen forming curvature radius is established. The predicted results are consistent with the experimental results, and the maximum relative deviation is 2.6%.
Increase in ironing limit of stainless steel cups with lubricants containing ceramic particles
Authors: Abe Y , Yamashita T , Mori K
Published: December 2022

The seizure resistance in the ironing process of stainless steel cups was improved with lubricants containing Al2O3 particles, and the ironing limit of the cups was increased. The effects of suspending different concentrations of Al2O3 particles in paraffin based oils on increasing the ironing limit of SUS430 cylindrical cups before seizure were investigated using a lapped tungsten carbide die. By containing c = 2vol% of Al2O3 particles having nominal diameter d between 0.02 to 4 micrometres in an oil with a kinematic viscosity of 500 mm2/s, the ironing limit of the cup was 8% under a punch speed of 100 mm2/s. The limit was similar to the limit using a commercial low-viscosity oil with chlorine additive. The kinematic viscosity of the base oil was reduced. In d = 0.2 μm and c = 0.5vol%, the limit of the oil more than kinematic viscosity of 180 mm2/s was similar to the limit by the commercial oil. In d = 4 μm and c = 1vol%, the limit of the oil having more than kinematic viscosity of 100 mm2/s was effective. It was found that the seizure resistance in the ironing process was improved by the proper ironing conditions with lubricants containing particles.
Analysis of the properties and microstructure of ultra-thin tube
Authors: Yan J P , Zhao R , Meng B , Wan M , Wang Z X
Published: December 2022

In order to satisfy the requirement of the engine heat exchangers, ultra-thin tubes with higher dimensional accuracy and better performance are required. Inconel 718, as the basic material of ultra-thin tube, is one of the materials that can meet the requirements of the engine heat exchanger. In this study, ultra-thin tubes with diameters and thicknesses of 1.50mm and 0.050mm were prepared by floating plug drawing process. The results showed that the yield strength increased and the corresponding elongation decreased with the increase of drawing passes. The wall thickness of the ultra-thin tube can be controlled by floating plug drawing. And the inner surface quality was greatly improved compared with the initial tube. The inner surface roughness can be controlled below 1.7μm. The average grain size after drawing can be reduced from 4.9μm to 2.1μm.
Crystal plasticity modeling on the selective laser melted AlSi10Mg alloy
Authors: Luo Z X , He J P , Li D Y , Peng Y H
Published: December 2022

Additive manufacturing (AM) has been developing into a revolutionary technique, in which parts are created by additive processing as opposed to the conventional subtractive manners. AM components possess the characterization of special microstructure and porosity. In this paper, a computational method is developed to investigate the mechanical property of selectively laser melted (SLM) AlSi10Mg alloy. The DREAM.3D software is utilized to generate a polycrystal model based on electron backscatter diffraction (EBSD) results. The investigated alloy shows a weak texture that the grain preferential grows along the <100> orientation. The real defect geometries are reconstructed from X-ray Computed Tomography (XCT) experimental slices and embedded into a representative volume element (RVE) model. Furthermore, a crystal plasticity (CP) model integrated fast Fourier transform method (FFT) in Düsseldorf Advanced Material Simulation Kit (DAMASK) package is implemented to simulate the mechanical response for the RVE model. The effect of porosity on tensile strength is studied, and result shows the defects degrade tensile strength.
Evaluation on dimensional stability of Cf/AZ91D composite based on the micro-yield strength
Authors: Zhou J M , Yun K , Chen Z , Qi L H
Published: December 2022

The dimensional instability caused by irreversible micro-plastic deformation can be evaluated with the micro-yield strength. Cf/Mg composite material prepared by liquid-solid extrusion following vacuum infiltration(LSEVI) process was taken as testing material and its dimensional stability was evaluated. The load-unload cycle test method is used to explore the stress range for the Cf/Mg composite to generate residuals plastic strain in static conditions. The results show that micro-plastic deformation for Cf/Mg composite material occurred in the stress range between 35 and 45 MPa. When the micro-plastic strain reaches 10−5, the micro-yield strength of the Cf/Mg composite material is evaluated as 79MPa. Compared with matrix alloy, the micro-yield strength has increased by more than 89%, which is the same level as beryllium alloy. This paper provides an effective strategy for characterize the dimensional stability of continuous fibre reinforced metal matrix composites.
A study on electric pulse treatment of stainless steel constructive forming process
Authors: Deng J D , Han T , Li W T , Wang F , Qian D S
Published: December 2022

The constructive forming process is a new plastic forming process of manufacturing heavy forgings from small blank units. In this process, first, the surfaces of the blank units are cleaned, and then the blank units are packaged into a whole blank, finally, the whole blank is deformed into a heavy forging by thermal deformation in a vacuum. In order to solve the key problem of constructive forming which is bonding interface healing, electric pulse treatment was introduced to regulate and control bonding interface healing. Through the electric pulse treatment experiments of stainless steel blanks before and after high temperature deformation, the effects of electric pulse treatment on the geometric morphology, microstructure and chemical composition of stainless steel bonding interface were revealed. The results indicate that using electrical pulse treatment before high temperature deformation can pre-connect the bonding interface and promote the thermal deformation healing of the bonding interface, using electrical pulse treatment after high temperature deformation can promote the healing of micro-voids in the bonding interface area and further improve the healing effect of the bonding interface. The research results provide a new idea for solving the problem of interfacial traceless bonding technology in metal constructive forming.
Key technologies of cooling and lubrication for closed hot extrusion automatic production line
Authors: Guo Y Q , Cui J H , Pan L D , Li S
Published: December 2022

For the problems that the stability problem that affects the fully automated production of precision extrusion of cylindrical parts, the cooling and lubrication of the die under high temperature and high pressure is the key technology that affects the production stability. During the hot extrusion process, the punch die has a short life under high temperature and high pressure, and cannot be Achieving continuous production and maintaining the life of the punch is the key technology to realize high-efficiency unmanned production of hot extrusion automation. First, the temperature rising and cooling formula for die especially for punch was obtained by theoretical calculation. The convective heat transfer coefficient on the surface of the internal cooling pipe was calculated and punch cooling device was made based on the forced convection heat transfer of cooling water. The changing law of the temperature field after punch extrusion was obtained by the infrared temperature measuring device and the test results were consistent with the theoretical calculation results.
Research on the edge effect of 7075 aluminium alloy damaged aircraft component strengthened by laser shock peening
Authors: Cheng X Q , Zhang J H , Cheng S Z , Xia Q X
Published: December 2022

Laser shock peening (LSP) is a promising surface strengthening process in the field of aircraft maintenance. However, unreasonable residual stress distribution often exists at the edge of the damaged aircraft component strengthened by LSP, which results in a significant decrease in strengthening effect of LSP. To explore the residual stress distribution after LSP in the edge region of components and reveal the influence of edge effects on deformation and inducing residual stress, the finite element (FE) models of LSP on 7075 aluminum alloy was established based on ABAQUS. The reliability of the FE model was verified by comparing the experiment and simulation results. The residual stress distribution in the edge and center region after LSP were analyzed. The results show that the edge effect enhances the flow of material to the edge and introduces tensile stress in this direction, thereby reducing the overall residual compressive stress level in the edge region. The influence range of edge effect on residual stress distribution is about 70% of the laser spot diameter. Besides, edge effects reinforce the phenomenon of residual stress holes, which results in a reduction of the maximum value by 109.2MPa. The influence of edge effect can be solved by multi surfaces LSP.
Prevention of peeling of Al-Si coated layer in hot stamping using corner thickening by planar compression
Authors: Maeno T , Ohtsuka Y , Talebi-Anaraki A , Watanabe R
Published: December 2022

Hot-stamped products are widely used for the body in white of an automobile to enable lightweight design and improve crashworthiness. Al-Si coated 22MnB5 steel sheets are applied to prevent oxide scale and adhere to a painting in hot stamping. To strengthen the bent member, corner thickening by planar compression in hot stamping was applied. However, the Al-Si coating layer peels off by large deformation due to corner thickening. The effect of corner thickening on the peeling of the Al-Si coating layer was investigated in hat-shaped bending. The coating layer on the outer corner was cracked by tensile deformation and the peel of the coating layer was observed above 5% in the thickening ratio. Deformability of the coating layer without crack was investigated in V-shaped bending. The sidewall angle was changed to taper to prevent peeling failure. In addition, to improve the elongation of the coating layer during hot stamping, the heating temperature was increased. The peeling and crack of the coating layer were reduced by heating at 1050 °C for 4 min.
Study on anti-barrel deformation of ultrasonic-assisted upsetting
Authors: Zhu N Y , Chen J L , Lai W K , Zuo S B
Published: December 2022

Anti-barrel shape is a typical phenomenon for a cylinder deformed in the upsetting process superimposed with sufficiently high intensity of ultrasound. In this paper, the cylindrical specimens of aluminum 6061, ϕ 4.08mm×4.8mm, were performed as the experimental object. With the different temperatures of 350°C, 400°C and 500°C and the longitudinal vibration amplitudes of 6μm and 10μm, the anti-barrel forming law of cylindrical specimens was studied, as well as the material flow law in the forming process. Results show that, the anti-barrel profiles may show up elliptic and hyperbolic curves, as well as the circular arc. The forming process of anti-barrel profile consists of multiple processes of high-speed collision, low-speed collision, high-speed compression and low-speed compression. The formation of anti-barrel profile may effectively promote the uniform flow of the end material and avoid upward-moving of the lateral material which is inevitable in conventional upsetting. The barrel and anti-barrel profiles perform almost opposite types of hot-working streamline, of which the layout of arcs opening inward and outward respectively.
Plastic deformation behavior of bending aluminum fiber porous material under compressive load
Authors: Li J , Peng Y H , Zhang Y X , Zhang Z R , Wu F
Published: December 2022

The 6061 aluminum alloy wires with diameters of 0.15 mm and 0.20 mm were cut into different structural sizes of 5 × 10 mm and 10 × 15 mm by a spring machine to bend the aluminum alloy fibers, one is 5 mm short side, 10 mm long side, and 1 mm arc radius, and the other is 10 mm short side, 15 mm long side, and 1 mm arc radius. Special cylindrical molds are used to prepare folding sheets with different porosities using vacuum hot pressing sintering technology. Bent aluminum fiber porous material. The gas displacement method was used to detect the pore size and pore size distribution, and the Plastic Deformation Behavior were analyzed by quasi-static uniaxial compression test. Research shows that the material presents a three-stage stress-strain curve, from the initial nonlinear elastic deformation stage to the pseudo-platform stage and the densification stage, the wire diameter and structure of the material The smaller the size, the more conducive to the densification of the silk skeleton, and the smaller the average pore size formed, the higher the compressive strength.
Spinning deformation mechanism of aluminum alloy cylinder with multi-level stiffeners based on numerical simulation
Authors: Meng Y H , Yu X P , Lai Z L , Zhao Y X , Yu Z Q
Published: December 2022

This paper focuses on the deformation mechanism of aluminum alloy cylinder with multi-level stiffeners in flow spinning. A flow spinning finite element model is established based on ABAQUS software, and the material flowing and damage behavior between different width stiffeners were analyzed. The research results can provide guidance for spinning process of aluminum alloy cylinder with multi-level stiffeners.