Search

Purpose The purpose of this paper is to predict the response and perforation of fibre metal laminates (FMLs) subjected to impact by projectiles at different velocities. Design/methodology/approach A finite element (FE) model is constructed in which recently proposed dynamic constitutive models for fibre reinforced plastic (FRP) laminates and metals are used. Moreover, a recently developed dynamic cohesive element constitutive model is also used to simulate the debonding between FRP laminates and metal sheets. The FE model is first validated against the test data for glass laminate aluminum reinforced epoxy (GLARE) both under dropped object loading and ballistic impact, then used to perform a parametric study on the influence of projectile nose shape on the perforation of FMLs. Findings It is found that the present model predicts well the response and perforation of GLARE subjected to impact loading in terms of load-time history, load-displacement curve, residual velocity and failure pattern. It is also found that projectile nose shape has a considerable effect on the perforation of GLARE FMLs and that the ballistic limit is the highest for a flat-ended projectile whilst for a conical-nosed missile the resistance to perforation is the least. Originality/value Recently developed constitutive models for FRPs and metals, together with cohesive element model which considers strain rate effect, are used in the FE model to predict the behaviour of FMLs struck by projectiles in a wider range of impact velocities; the present model is advantageous over such existing models as Johnson-Cook (JC) + Chang-Chang and JC (+BW) + MAT162 in terms of failure pattern though they produce similar results for residual velocity.

The measurements of K-shell ionization cross sections for Fe, Ni, and Zn were performed using 7–29 keV electron impact on thick targets. Monte Carlo simulations were employed to correct the effects due to the multiple-scattered electrons and bremsstrahlung photons as well as other secondary particles within the thick targets. The so-called Tikhonov regularization method was adopted to deal with the ill-posed inverse problem involved in the thick-target method. The experimental results were compared with the DWBA and PWBA-C-Ex predictions as well as existing experimental data from the literature. It is observed that our experimental data are in better agreement with the theoretical results based on the DWBA model developed by Bote et al.

The Lα, Lβ, and Lγ x-ray production cross sections and M-shell x-ray yields by 5–29 keV electrons bombarding a thick Pb target were measured. The effects of multiple-scattered electrons, from the bremsstrahlung and other secondary particles within the thick sample were corrected using the Monte Carlo simulations. The experimental results are compared with the DWBA predictions of Bote et al., and also with the experimental data from the literature. The results indicate that the measurements of the production cross sections for the L subshells of the elements with higher atomic numbers using the thick-target method are feasible and reliable.

This study investigated the effects of shading on photosynthesis in 3-year-old potted apple trees. The trees were grown either in full sunlight or in a shade environment with about 50% of sunlight filtered through black plastic nets. Under the shade conditions, the net photosynthetic rate (PN), the stomatal conductance, the transpiration rate, and the intercellular CO2 concentration decreased before midday, which was due to low light energy but the PN of the shaded trees increased relative to the control trees during the afternoon. In addition, the concentrations of chlorophyll (Chl) a, b, and total Chl increased in the shaded trees. In shaded apple trees, the photochemical efficiency increased. There was a lower content of reactive oxygen species and activities of antioxidant enzymes. The results showed that moderate shading can improve the total photosynthetic efficiency, which is mainly attributed to alleviation of photodamage and low accumulation of reactive oxygen species.

The I-mode is a promising operation mode for fusion in the future, featuring high-temperature and low-density confinement, but the reason why the temperature and density are decoupled remains an important aspect to be explored. The experimental results from the experimental advanced superconducting tokamak (EAST) showed that the weakly coherent mode (WCM) is directly related to sustaining the I-mode and that the peak amplitude of the WCM is proportional to the temperature in the pedestal. Simulating the experimental data from EAST with the six-field model of BOUT++, we find a density perturbation close to the frequency of the WCM observed in the experiment. By testing all the physical terms in this model, we find that the density perturbation and particle transport are directly related to the drift Alfvén wave (DAW) mode. We also use the SymPIC program (Xiao et al Plasma Sci. Technol. 20 110501; Phys. Plasmas 22 112504; Plasma Sci. Technol. 23 055102) to simulate the same experimental data and find that the frequency range of the WCM is close to both experimental and BOUT++ results. Therefore, the WCM of the I-mode can be considered to be driven by the DAW, which helps improve the transport of the I-mode.

We report crystal growth, magnetic properties and electron spin resonance (ESR) study of the one dimensional zigzag-chain compound FeNbO4. The single crystals were grown by the flux method using Na2WO4·12H2O and Na2W2O7 as the flux. Magnetic susceptibility and specific heat data show an antiferromagnetic ordering below 44 K. High-field magnetization data reveal a spin-flop transition at 12 T when magnetic field is applied along the magnetic easy axis. Multi-frequency ESR study on the single crystals reveal three resonance modes which can be understood by the molecule-field theory. Using a simple model with easy-axis type anisotropy, we estimate that the anisotropy field HA and the exchange field HE are 2.67 T and 27 T, respectively. The zero-frequency resonance field at 11 T corresponds to the spin-flop transition, demonstrating a close correlation between the high-field magnetization and the ESR spectra.

As further progress in the accurate and efficient computation of coupled partial differential equations (PDEs) becomes increasingly difficult, it is highly desired to develop new methods for such computation. In deviation from traditional approaches, this short communication paper explores a computational paradigm that couples numerical solutions of PDEs via machine-learning (ML) based methods. Particularly, it solves PDEs in subdomains as in a conventional method but develops and trains artificial neural networks (ANN) to couple the PDEs at their interfaces, leading to their solutions in the whole domains. The concepts and algorithms for the ML coupling are discussed via computation of coupled Poisson equations and coupled advection-diffusion equations. Unlike in a conventional method, Schwarz iteration may not be necessary for the ML coupling in computation of the latter. Numerical examples show that the coupling can generate solutions to these equations with acceptable accuracy. They also illustrate that it exhibits predictability; ML algorithms trained with a set of initial and boundary conditions still work in computation when the conditions are modified. Although preliminary, this exploratory study indicates that the ML paradigm is promising in terms of feasibility and performance and deserves further research.

A group of Ti-25Nb-xMn-ySn (in wt%; x = 2, 4 and y = 1, 5) alloys were designed using the "BF-d-electron superelasticity" empirical relationship and subsequently were cast in order to investigate their microstructure, deformation and superelastic behaviors. Monolithic β phase is found in all investigated alloys except in Ti-25Nb-2Mn-1Sn alloy which exhibits α"+β dual-phase microstructure. During compression testing, the Ti-25Nb-2Mn-1Sn alloy fails and demonstrates sufficient plasticity of ~ 41% and ultimate compressive strength of ~ 1800 MPa, where other alloys do not fail within the load capacity of 100 kN. Among all the investigated alloys, Ti-25Nb-4Mn-1Sn alloy exhibits the highest yield strength (~ 710 MPa) while Ti-25Nb-2Mn-1Sn alloy possesses the highest hardness (~ 244 HV). In this work, yield strength is influenced by solid solution and grain boundary strengthening while hardness is affected by the amount of constituent phases in each alloy. Additionally, Ti-25Nb-4Mn-1Sn shows highest recoverable strain (2.35%) and superelastic recovery ratio (90%) during cyclic loading-unloading up to 3% strain level, with highest total energy absorption among the investigated alloys. Moreover, all the Ti-25Nb-xMn-ySn alloys display shear bands except that Ti-25Nb-2Mn-1Sn alloy displays shear bands together with some cracks on the outer surface of compressively deformed morphologies.

In this work, a novel serial of Ti-33Zr-xFe-yCr (x = 3, 5, 7 wt% and y = 2, 4 wt%) alloys was designed first with an expectation to obtain Laves phase in microstructure and then these alloys were produced using cold crucible levitation melting. Microstructure and phase analyses suggest the precipitation of a C15 type Laves phase with a dominating β phase in all the Ti-33Zr-xFe-yCr alloys except in Ti-33Zr-3Fe-2Cr alloy which has a single β phase microstructure. The volume fraction of the Laves phase increases upon increasing the Fe and Cr concentrations in Ti-Zr-Fe-Cr alloys. Mechanical properties evaluation reveals the highest ultimate compressive strength (~2 GPa) and superior plastic strain (33.6%) in Ti-33Zr-3Fe-4Cr alloy. Moreover, all the studied alloys exhibit extraordinarily high yield strength above 1 GPa and hardness exceeding 8 GPa. Embrittlement in Laves phase alloys, which is a common problem, is not encountered in this work as all the studied alloys display plastic strain including maximum elongation of 40%. The fracture behaviour of each studied alloy is also discussed in terms of the influence of Laves phase on a fracture, shear banding pattern and plastic deformation. Keywords: Titanium alloy, Laves phase, Intermetallic compound, Mechanical strength, Plasticity

Cu 3 Nb 2 O 8 belongs to a new multiferroic family with coexisting structure and magnetic chiralities. In this work, we report on the flux growth of Cu 3 Nb 2 O 8 single crystals using a V 2 O 5 -K 2 MoO 4 mixture as the flux with a 5:1 ratio. The obtained crystals have an average size of 3 × 3 × 2 mm 3 and high quality determined from X-ray diffraction, specific heat and susceptibility measurements. The experimental results on the single crystals reveal robust anomalies at 26.2 K and 24.5 K in specific heat and magnetic anisotropy along different crystallographic axes, which provide a better understanding of this fascinating multiferroic compound.

Based on the Froude similarity law, a small-scale tunnel model (1/14) was built based in this study to investigate critical velocities of tunnels. Critical velocity is the minimum air velocity required to resist the spread of smoke from a fire upstream in a tunnel. A set of experiments was conducted to investigate the critical velocities under different experimental conditions by varying the heat release rate of the fire, ambient temperature, operating pressure and arrangement of the nozzles. The results of the tests with no spray indicated that the ambient temperature has little impact on the critical velocity. Moreover, based on the dimensionless analysis method, a new correlation was established to predict the critical velocities in the tunnel without Water spray-based Fixed Fire Fighting Systems (WFFFS). The accuracy of the correlation was illustrated by the results of the present tests and a number of tests on different scales published by other scholars. Furthermore, 60 tests with WFFFS activation were carried out. The results show that the critical velocity is significantly reduced after the water spray discharged from the nozzles. The maximum reduction of the critical velocity is approximately 31%. The reduction of the critical velocity strongly depends on the number, positions and operating pressures of the nozzles. The mechanisms of the reduction of the critical velocity caused by spraying were discussed. The cooling effect of the water droplets on hot gas is not the only mechanism for decreasing the critical velocity caused by spraying. Spraying increases the inertial force of the longitudinal airflow and is the other mechanism for the reduction.

NiWO 4 exhibits a spin chain structure built by magnetic Ni 2+ ions, which may be considered as a one dimensional S = 1 system. In this work, large-sized single crystals of NiWO 4 were successfully synthesized by a flux method and the crystal quality was confirmed by X-ray diffraction. Magnetic properties of obtained single crystals were studied by means of magnetic susceptibility and high field magnetization along crystallographic axes. The results demonstrate that NiWO 4 is highly magnetic anisotropic and possesses a three-dimensional long range ordering below 60 K, where a spin flop transition can be observed at 17.5 T in applied magnetic fields along the magnetic easy axis (c-axis).

Numerical analysis of slab heating characteristics in a reheating furnace was accomplished using fluid dynamics software FLUENT. The complicated geometry of the mesh using finite volume method (FVM) simulation was built based on the practical aspects of the reheat furnace. The effect of slab of flow field and temperature distribution inside the furnace on heating efficiency and uniformity in heating was studied. The phenomena in the furnace were periodically transient when slabs were heated with controlled time interval. A user-defined function (UDF) program was developed to process the sequence pulse combustion because FLUENT cannot handle the movement using its default functions. The numerical results were in good agreement with the corresponding experimental data. In order to improve the heating efficiency, the heating precision and the temperature uniformity of the medium and heavy slab, a basic model is proposed. The study is directly applicable in optimizing the process.

In this study, the removal performance of a hybrid ozonation-coagulation (HOC) process using AlCl36H2O (Al-HOC) and FeCl36H2O (Fe-HOC) as coagulants for the treatment of wastewater treatment plant (WWTP) effluent and ibuprofen (IBP) was investigated. Compared with the conventional coagulation process and pre-ozonation-coagulation process, much better organic matter removal performance can be achieved for both the Al-HOC and Fe-HOC processes. The Fe-HOC process showed an obviously higher dissolved organic carbon (DOC) removal efficiency than that of the Al-HOC process. Surface hydroxyl groups were determined to be the active sites in generating OH in the HOC process, and the hydrolysed Fe species possessed a higher content of surface hydroxyl groups than the hydrolysed Al species according to fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectra (XPS) analyses. In addition, the hydrolysed Fe species contained a higher portion of tetrahedral sites that were more likely to be stronger Lewis acid sites to react with ozone to generate OH. Furthermore, peroxone reactions in the HOC process were other possible way to enhance the OH generation, and higher H2O2 generation was observed in the Fe-HOC process due to higher O2- generation. Therefore, better removal performance of the Fe-HOC process can be obtained due to the increased OH generation in the Fe-HOC process.

This study evaluated the effects of sodium selenite (SS) and coated SS (CSS) addition on performance, ruminal fermentation, nutrient digestibility and hepatic gene expression related to lipid metabolism in dairy bulls. Thirty-six Holstein bulls were randomly divided into three groups: without Se addition, addition of 0.3 mg/kg dry matter (DM) of Se from SS and addition of 0.3 mg/kg DM of Se from CSS, respectively. Dietary Se addition increased DM intake. Higher average daily gain and lower feed conversion ratio was observed for CSS addition. Ruminal pH and acetate to propionate ratio decreased, total volatile fatty acids concentration increased but ammonia-N concentration was unchanged with dietary Se addition. Apparent total-tract digestibility of DM, organic matter and crude protein was highest for CSS addition, followed by SS addition and then control. Bulls receiving Se addition had higher digestibility of ether extract, neutral detergent fibre and acid detergent fibre. Serum glucose and glutathione peroxidase and hepatic expression of peroxisome proliferator-activated receptor-α, sterol regulatory element-binding protein-1, carnitine palmitoyl transferase-1 and acetyl-CoA carboxylase-α was highest for CSS addition, followed by SS addition and then control. Bulls receiving CSS addition had higher serum total protein, albumin, triglyceride and total antioxigenic capacity. Addition of Se increased serum cholesterol, insulin and Se. Hepatic expression of stearoyl-CoA desaturase and 3‑hydroxy‑3-methylglutaryl-CoA reductase and Se content increased but content of total lipid and triglyceride was unchanged with Se addition. The data indicated that addition of Se increased performance and hepatic expression of gene related to lipid metabolism in bulls.

In order to improve the dissolved organic matter removal efficiency, an electro-hybrid ozonation-coagulation (E-HOC) system was developed in this study, in which the electro-coagulation (EC) and ozonation occurred simultaneously in one integrated unit. Higher removal efficiency was observed for the E-HOC process compared with those of EC, ozonation and pre-ozonation-EC process for the treatment of wastewater treatment plant (WWTP) effluent and ibuprofen (IBP). 58.6% dissolved organic carbon (DOC) removal efficiency was achieved in the E-HOC process for the treatment of WWTP effluent at optimal operational condition (current density 15 mA/cm2, initial pH 5 and ozone dosage 1.5 mg O3/mg DOC). Based on the reactive oxygen species (ROS) detection and reactions on the electrodes, the synergistic effects between ozone and coagulants (SOC) were found to be involved in the E-HOC process. According to pseudo-first-order rate constant analyses, the contribution of five possible organic removal pathways was quantified. It was revealed that the peroxone and SOC effects exhibited almost equal contribution to IBP removal at initial pH 5 under different current densities, both of which played the dominant role in the E-HOC process. However, the contribution of the SOC effects decreased significantly when the initial pH increased to 7 and 9. As an important pathway for organic removal in the E-HOC process at initial pH 5, the mechanism of the SOC effects was analysed at initial pH 5. It was revealed the SOC effects can further improve hydroxyl radicals (•OH) generation, and the surface hydroxyl groups of the hydrolysed Al species generated from anode electrolysis were determined to be the active sites to generate ROS in the SOC effects.

In order to achieve an effective balance between plasticity and strength, a group of Ti-26Nb-xZr-yMn (x = 4, 7, 10 wt% and y = 3, 5 wt%) alloys were designed to evaluate the effects of Mn and Zr on the microstructures, mechanical properties and strengthening effects of the Ti Nb system. All the investigated alloys illustrate a monolithic β phase in their microstructure and they all possess substantial true plasticity (~160%) and true maximum strength (~ 950 MPa) without fracture during the compression tests within the load capacity of 100 kN. The contribution of solid-solution, grain-boundary and dislocation strengthening mechanisms have been evaluated using the strengthening model for β Ti alloys for all the investigated alloys. Among the investigated alloys, Ti-26Nb-4Zr-5Mn demonstrates the highest true yield strength (654 MPa), dislocation density (2.45 × 1015 m−2) and hardness (242 HV) along with improved strain hardening ability in terms of strain hardening indices (0.42 and 0.09). Furthermore, based on the superior mechanical properties among the investigated alloys, the electrochemical performance of Ti-26Nb-4Zr-3Mn and Ti-26Nb-4Zr-5Mn have also been analyzed in this work. The electrochemical measurements show that both alloys have almost similar corrosion potential and corrosion current density in simulated body fluid, i.e., −0.45 V and 0.838 nA/cm2 for Ti-26Nb-4Zr-3Mn, −0.48 V and 0.839 nA/cm2 for Ti-26Nb-4Zr-5Mn, respectively.

AIM To analyse the outcomes of oesophageal stenting for malignant strictures and to study the correlation between the follow-up time and major complications. MATERIALS AND METHODS Patients with oesophageal malignancy who underwent stent placement between 2011 and 2016 for dysphagia were included. The data included age, sex, dysphagia, length and location of stenosis, date of stent placement, complications, follow-up time, and survival. RESULTS Two hundred and ninety-eight patients were included in the study. Minor complications occurred in 113 patients (37.9%) including chest pain (17.1%), foreign body sensation (25.5%), hiccups (1.68%), and reflux symptoms (27.5%). Major adverse events occurred in 93 (31.1%) patients including pneumonia (25.5%), migration (3%), perforation (0.67%), bleeding (1.68%), and restenosis (22.5%). oesophago-airway fistula occurred in 45 (15.1%) patients. The incidence of recurrent dysphagia, pneumonia, and oesophago-airway fistula increased over 3 months and decreased after another 3 months. The incidence of major complications as a percentage of survivors remained high after 3 months (>40%). Spearman analysis revealed a significant positive correlation between the incidence and the follow-up time over this period (rs=0.907, p CONCLUSION The major complications of oesophageal stenting increased with time over 3 months and remained high for another 3 months. Therefore, stenting should be considered for palliation in patients with short expected survival (usually

A series of Ti-25Nb-8Zr-xCr (x = 0, 2, 4, 6, 8 wt%) alloys were designed based on DV-Xα cluster method and e/a¯-Δr¯ diagram with an anticipation to obtain high plasticity and significant strain hardening. The designed alloys were produced through cold crucible levitation melting technique in order to effectively investigate their microstructures and mechanical properties. The addition of Cr significantly enhances the β stability in the microstructures of the Ti-25Nb-8Zr-xCr alloys. Both yield strength and hardness of the studied alloys increase due to the effect of solid-solution strengthening. By constrast, the plasticity, maximum strength and strain hardening rate are influenced by the β stability as well as the distinct deformation mechanisms. None of the alloys comprising Cr fail up to 100 kN (the load capacity used) and all show impressive plasticity (~75%) and superior maximum compressive strength (~4.5 GPa) at 100 kN. Moreover, the deformation bands, which are found around the hardness indentations, are analyzed for all the investigated alloys. The fracture behaviors of the Ti-25Nb-8Zr-xCr alloys are also studied to observe the characteristics related to crack propagation, plastic deformation and the formation of shear bands. Keywords: Titanium alloy, Plasticity, Strength, Strain hardening, Deformation band, Shear band

An impressive strengthening ability of Laves phases is favorable to develop titanium alloys with an improved trade-off between strength and plasticity. Therefore, the Ti-xZr-7Fe-ySn (x = 25, 30, 35 wt% and y = 1, 2 wt%) alloys were first designed in such a manner that a Laves phase would precipitate in these alloys and then the investigated alloys were produced by cold crucible levitation melting. A hexagonal close-packed C14 type Laves phase along with a dominant fraction of body-centered cubic β phase are formed in all the as-cast Ti-xZr-7Fe-ySn alloys except in Ti-25Zr-7Fe-2Sn. The volume fraction of the Laves-C14 phase is found to be sensitive to the quantities of Zr and Sn. Amongst all the investigated alloys, Ti-35Zr-7Fe-2Sn shows a better dislocation-pinning ability in terms of dislocation density (3.96 × 1015 m−2), yield strength (1359 MPa) and hardness (437 HV), whereas Ti-25Zr-7Fe-1Sn shows a better deformation ability in terms of compressive strain at failure (36.2%) and plastic strain (31.9%). Crack propagation, regions of dimples and deformation bands are examined in the fracture analyses. Moreover, in this work, Ti-25Zr-7Fe-1Sn exhibits the best strength and plasticity trade-off in terms of a product of ultimate strength and compressive strain at failure (77.4 GPa %).

To study the fatigue damage of a cutter used for cutting cashew nut, the integratedsimulation platform is established with Hypermesh, LS-Dyna, LS-PrePost, and nCode GlyphWorks.The simulation model is established by Hypermesh. LS-Dyna is used to calculate the k file.LS-PrePost is used as the post-processing software. The rain-flow counting, load superposition andextrapolation are executed using Rainflow module in nCode GlyphWorks. The analysis of thefatigue damage of the cutter is executed using Stress Life module in nCode GlyphWorks. Theequivalent stress time history of different elements in the upper and lower cutters, rain-flowcounting histogram after load spectrum superposition, rain-flow counting histograms after loadspectrum extrapolation, and damage histogram of the cutter are obtained. The results show that thecutter has excellent mechanical properties, and the minimum fatigue life of the cutter is about 495days, which is a conservative solution.

The curvelet transform is a known tool used in the attenuation of coherent and incoherent noise in seismic data. It utilises the fact that signal and noise are usually better separated in the curvelet domain than in the time-space (TX) domain. Coefficients of the transform are not independent and neighbouring coefficients are strongly correlated, which existing curvelet-based noise attenuation algorithms do not fully utilise. In this work we propose to use a data structure called a ‘dip map’ to describe dip information in seismic data. This information links local curvelet coefficients together in adaptive thresholding or subtraction of curvelet coefficients in seismic denoising algorithms. We used the dip map to improve curvelet multiple subtraction algorithm and the results show significant improvement over traditional methods with real data.

Recent house price variation has strongly affected households’ housing wealth and debt, yet the non-economic consequences of these changes in housing wealth are still poorly understood. Using a sample of 19,000 individuals from the Household, Income and Labour Dynamics in Australia Survey (HILDA) for 2001–2015, we examine the relationship between house price fluctuations and individual health by exploiting large exogenous changes in house prices in Australia. We find that an increase in local house prices is associated with a positive effect on the physical health of outright owners and a negative effect on the physical and mental health of renters. Improvements in physical health for outright owners can be partially attributed to health-related investments and behaviours such as a reduction in weight, an increase in physical exercise and an increase in time allocated to home production. These findings support the presence of a health-wealth gradient through the wealth mechanism distinct from the effects of local area amenities and macroeconomic conditions. Our findings highlight some of the often-overlooked social impacts – both positive and negative – of fluctuations in the housing market.

The invariance of the standard model (SM) under the CPT transformation predicts equality of particle and antiparticle masses. This prediction is tested by measuring the mass difference between the top quark and antiquark (Δmt=mt−mt‾) that are produced in pp collisions at a center-of-mass energy of 8 TeV, using events with a muon or an electron and at least four jets in the final state. The analysis is based on data corresponding to an integrated luminosity of 19.6 fb−1collected by the CMS experiment at the LHC, and yields a value of Δmt=−0.15±0.19(stat)±0.09(syst) GeV, which is consistent with the SM expectation. This result is significantly more precise than previously reported measurements. © 2017 The Author(s)

A non-intrusive global/local algorithm with non-matching (incompatible) interface is proposed to evaluate the durability of large-scale structures with local nonlinearity both on the basis of local multigrid strategy and the domain decomposition (DD) method, which can serve as an intermediate way to perform analyses of complex structures. The proposed algorithm couples a global linear elastic analysis (on coarse mesh) with a local nonlinear analysis (on fine mesh), which extends the iterative global/local method to treat non-matching partition interfaces. Furthermore, to deal with non-matching interface the framework of localized Lagrange multiplier (LLM) method is introduced, and a feasible but robust data transfer method is established with radial basis function (RBF) interpolation. Aitken’s acceleration method is adopted to increase the convergence rate. The convergence property and accuracy of this non-intrusive algorithm are investigated for a two-dimensional model with different interface geometries and interface node allocations. The effect of reduced integration on the convergence rate is also concerned in verification. Then, it is further verified with a three-dimensional model. Numerical results reveal that this non-intrusive algorithm is robust in the non-matching interface data transfer procedure, which is significant in error control during iterations, and it has good performance in both convergence and accuracy.

To improve the accuracy of impact failure prediction of ductile material under complex stress states, a novel multi-parameters dynamic ductile fracture model with constitutive relation and fracture criterion is proposed by involving the effects of hydrostatic pressure, Lode angle and strain rate. This novel dynamic fracture model is based on our proposed ductile fracture model under quasi-static loading. Furthermore, the corresponding material calibration strategy with some simple quasi-static and dynamic tests is also presented. In order to verify the present dynamic fracture model under complex stress states, both hydrostatic pressure and Lode angle, a plate specimen with notch made from Al 7075 was designed and the split Hopkinson bar (SHPB) tension tests with elevated loading forces were conducted. Meanwhile, parallel numerical simulations were performed with two fracture models, i.e., the Johnson–Cook model and the present novel model, implemented into the commercial finite element platform ABAQUS/explicit through user material subroutine VUMAT. By comparing with the numerical results and the SHPB experimental data, it is demonstrated that the novel dynamic ductile fracture model can predict favorably well with the SHPB experimental data. Furthermore, local strain rates and stress states of the specimen in the notch region during deformation were also studied.

The Ising-like antiferromagnet α-CoV2O6 has received considerable interests because of stabilized 1/3 magnetization plateau around 5 K under magnetic field applied along magnetic easy c-axis. In this work, this magnetization plateau was studied by varying temperature or rotating magnetic field. As temperature decreased, this stabilized plateau collapsed, and additional magnetic transitions were observed. As a result, a rich magnetic phase diagram was constructed and extended to temperature lower than previously reported. When magnetic field moved from the c to b (or a) axis, the magnetization plateau developed with field directions and vanished finally when the field was restricted in the ab plane. An impressive observation is that this 1/3-plateau can be stabilized and remain robust even when magnetic field deviated from the c axis, accompanied by the evolutions of the magnetic moments and the critical transition fields. We suppose that the origins of these temperature and angular dependences of the 1/3 magnetization plateau are related to strong spin-orbital coupling. Indeed, electron spin resonance (ESR) measurement gives large Lande factor of 8.9, evidencing that there exists strong spin-orbital coupling.