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Deep Learning Predicts Stress–Strain Relations of Granular Materials Based on Triaxial Testing Data

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Computer Modeling in Engineering & Science. 2021年第7期128卷 129-144页

作者： Tongming Qu Shaocheng Di y.T.Feng Min Wang Tingting Zhao Mengqi Wang Zienkiewicz ce.tre for Computational Engineering College of EngineeringSwansea UniversitySwanseaWalesSA18EPUK College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of TechnologyTaiyuan030024China Fluid Dynamics and Solid Mechanics Group Theoretical DivisionLos Alamos National LaboratoryLos AlamosNM 87545USA

This study presents an AI-based constitutive modelling framework wherein the prediction model directly learns from triaxial testing data by combining discrete element modelling(DEM)and deep learning.A constitutive learning strategy is proposed based on the generally acce.ted frame-indifference.assumption in constructing material constitutive *** low-dimensional principal stress-strain sequence.pairs,measured from discrete element modelling of triaxial testing,are used to train recurrent neural networks,and then the predicted principal stress sequence.is augmented to other high-dimensional or general stress tensor via coordinate *** detailed hyperparameter investigations,it is found that long short-term memory(LSTM)and gated recurrent unit(GRU)networks have similar prediction performance.in constitutive modelling problems,and both satisfactorily predict the stress responses of granular materials subjected to a given unseen strain ***,the unique merits and ongoing challenges of data-driven constitutive models for granular materials are discussed.

关键词： Deep learning granular materials constitutive modelling discrete element modelling coordinate transformation LSTM GRU

Review of fast methods for point-based computer-generated holography [Invited]

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Photonics Research 2018年第9期6卷 837-846页

作者： P.W.M.TSANG T.-C.POON y.M.WU Department of Electronic Engineering City University of Hong Kong Bradley Department of Electrical and Computer Engineering Virginia Tech

Computer-generated holography(CGH) is a technique for converting a three-dimensional(3D) object sce.e into a two-dimensional(2D), complex-valued hologram. One of the major bottlenecks of CGH is the intensive computation that is involved in the hologram generation proce.s. To overcome this problem, numerous research works have been conducted with the aim of reducing arithmetic operations involved in CGH. In this paper,we shall review a number of fast CGH methods that have been developed in the past decade. These methods,which are commonly referred to as point-based CGH, are applied to compute digital Fresnel holograms for an object space.that is represented in a point cloud model. While each method has its own strength and weakness,trading off conflicting issues, such as computation efficiency and memory requirement, they also exhibit potential grounds of synergy. We hope that this paper will bring out the essence.of each method and provide some insight on how different methods may crossover into better ones.

关键词：全息术计算机技术发展现状三维技术

Isovector pairing and particle-number fluctuation effects on the spectroscopic factors of one-proton stripping and one-neutron pick-up reactions in proton-rich nuclei

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Chinese Physics C 2018年第8期42卷 137-158页

作者： y.Benbouzid N.H.Allal M.Fellah M.R.Oudih Laboratoire de Physique Theorique-Facultéde Physique-USTHB BP32 El-Alia16111 Bab-Ezzouar-Alger-Algeria

Expressions of the spectroscopic factors（SFs） corresponding to one-particle transfer reactions have been established using a schematic *** expressions have been derived by taking into account the isovector neutron-proton（np） pairing correlations and a particle-number projection in the framework of the generalized SharpBCS（SBCS） *** proposed expressions of the projected wave-functions of odd-mass nuclei have been used for this *** formalism has first been tested using the single-particle energies of the schematic picketfence.*** is shown that the np pairing and particle-number fluctuation effects are far from negligible and they depend on the pairing gap parameter *** behavior is not the same when the parent nuclei are even-even or *** dealing with the SFs corresponding to one-proton stripping and one-neutron pick-up reactions in proton-rich nuclei have then been established within the framework of the realistic Woods-Saxon *** is shown that the np pairing effect as well as the particle-number projection effect are important and thus have to be included in future calculations of the SF corresponding to these kinds of reactions.

关键词： neutron-proton pairing particle-number projection spectroscopic factor

PREPARATION OF PEROVISKITE-TyPE La_(1-x)Sr_xMnO_3 AT LOW TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 153-156页

作者： Z.B. Shao, L.J. Zhang, y. Wang and y. T. Gu (Department of Chemistry, Northeastern University, Shenyang 110004, China) (Shenyang College of Education, Shenyang 110015, China) Dept. of Chem. Northeastern Univ. Shenyang 110004 China

Peroviskite-type Lal-xSrxMnO3 (0≤x≤0.3) was prepared through the solgel proce.s at low temperature (1100℃). The ethylene glycol and citric acid were used to make a sol-gel from an aqueous solution of lanthanum strontium and manganese nitrated. The particle-diameter distribution of powders is from 10 to 50urn, the mean particle size is about 35urn and the specific surface.area is about 92.5 to 98.5m2g-1 .Peroviskite type ***3 was synthesized at 1100℃, and the electronic conductivity of La1-xSrxMnO3 is 104-105S.m-1 from room temperature to 1000℃.

关键词： sol-gel nanometer size peroviskite-type conductivity

Impact of ce.tralization of pancreaticoduodenectomy coupled with fast track recovery protocol:a comparative study from India

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Hepatobiliary & Pancreatic Diseases International 2016年第5期15卷 546-552页

作者： Omar J Shah Sadaf A Bangri Manmohan Singh Reyaz A Lattoo Mohammad y Bhat Feroze A Khan Department of Surgical Gastroenterology Sher-i-Kashmir Institute of Medical Sciences

BACKGROUND: Fast track strategy in the management of patients undergoing intra-abdominal surgery of various types has emerged as a landmark approach to reduce.surgical stress and acce.erate recovery. This study was to evaluate the effect of fast track strategy on patients subjected to pancreaticoduo-denectomy (PD) from an individual unit during transit from low to a high volume ce.ter. METHODS: A total of 142 PD patients who had been subjected to fast track strategy between June 2008 and September 2012 were compared with 46 patients who had rece.ved convention-al surgery between January 2006 and May 2008. Comparative analysis was made of postoperative complications, postopera-tive recovery, length of hospital stay and patient readmission requirement. RESULTS: The patients subjected to fast track strategy had a faster recovery and a shorter hospital stay than those who were treated conventionally (7.8 vs 12.1 days). The intraoperative events like operative blood loss (417.9±83.8 vs 997.4 ±151.8 mL, Py lower in the fast track group. The frequency of pancreatic ifstula (4.9% vs 13.0%) and delayed gastric empty-ing (7.0% vs 17.4%) was also signiifcantly reduce. with fast track treatment. Nevertheless, the readmission rate (11.3% vs 6.5%) was found relatively higher within the fast track group. However, increased readmission rates in this study seem to be independent of fast track protocol. CONCLUSIONS: This preliminary analysis suggests that the fast track approach might be beneifcial to the well-being of the patients after PD, for it acce.erates the immediate clinical recovery of patients and signiifcantly shortens their length of hospital stay.

关键词： fast track recovery pancreaticoduodenectomy

MICROSTRUCTURE AND INCLUSION CHARACTERIZATION IN THE SIMULATED COARSE-GRAIN HEAT AFFECTED ZONE WITH LARGE HEAT INPUT OF A Ti-Zr-MICROALLOyED HSLA STEEL

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Acta Metallurgica Sinica(English Letters) 2005年第2期18卷 96-106页

作者： y.T.Chen X.Chen Q.F.Ding J.Zeng Technologyce.ter WuhanIronandSteel（group）CooperationWuhan430080China

The microstructure and the characteristics of the inclusions embedded in ferrite matrix in simulated coarse-grain heat affected zone (CGHAZ) of a Ti-Zr-treated high strength low alloy (HSLA) steel have been investigated. The microstructure of the simulated CGHAZ dominantly consisted of intragranular acicular ferrite (IAF) combining with a small amount of polygonal ferrite (PF), widmanst tten ferrite (WF), bainite ferrite (BF), pearlite and martensite-austenite (M-A) islands. The PF, WF and BF were generally observed at the prior austenite grain boundaries and the interlocking acicular ferrite was usually found intragranularly. It was found that the inclusions were composed of Ti2O3, ZrO2, Al2O3 locating at the ce.ter of the particles and MnS lying on the surface.layer of the inclusions. The intragranular complex inclusions promoted the acicular ferrite formation and the refinement of microstructure whilst those at prior austenite grain boundaries caused PF formation on the inclusions. The simulated CGHAZ consisting of such complicated microstructure exhibited desired mechanical properties.

关键词： microalloyed HSLA steel heat affected zone microstructure mechanical property inclusion acicular ferrite titanium zirconium

Harvesting,sensing and regulating light based on photo-thermal effect of Cu@CuO mesh

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Green Energy & Environment 2017年第4期2卷 387-392页

作者： Xuan Wu Jie Xu George y.Chen Rong Fan Xiaokong Liu Haolan Xu Future Industries Institute University of South Australia Mawson Lakes Campus Laser Physics and Photonic Device. Laboratories School of Engineering University of South Australia Mawson Lakes Campus School of Natural and Built Environments University of South Australia Mawson Lakes Campus

A system of light harvesting, sensing and regulating was designed based on the photo-thermal and Seebeck effect of flexible CuO nanostructures. Cu@CuO meshes were prepared via self-oxidation of Cu mesh and utilized as the photo-thermal material. Upon irradiation by visible light, the temperature of the Cu@CuO mesh dramatically increases. The temperature difference.between the irradiated and non-irradiated parts of the Cu@CuO mesh produce. a measurable voltage output due to the Seebeck effect. The generated voltage was then converted into a digital signal to control a rotary neutral-density disc to filter the rece.ved light. This enabled regulation of the intensity of the incident light at a selected region. This system is cost effective and has potential applications in greenhouses, factories and smart buildings to minimize energy consumption and improve wellbeing.

关键词： Photothermal Light CuO Nanostructure

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使用知识库系统的自动防空系统

情报指挥控制系统与仿真技术 1992年第2期14卷 17-24,49页

作者：林,ce.成文彩

DEFORMATION BEHAVIOR OF AA6063 ALUMINIUM ALLOy AFTER REMOVING FRICTION EFFECT UNDER HOT WORKING CONDITIONS

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 451-458页

作者： Z. y. Chen S. Q. Xu X.H. Dong National Die ＆ Mold CAD Engineering Research ce.ter Shanghai Jiaotong University Shanghai 200030 China College of Materials Science.and Engineering Taiyuan University of Technology Taiyuan 030024 China

The hot deformation behavior of AA6063 aluminium alloy has been investigated by means of compression tests at temperatures between 400 and 520℃, and strain rates ranging from 2.5 to 10 s^-1. Owing to the barreling, the theoretical model on the basis of Hills general method is used to calculate the flow stress of a cylindrical specimen under uniaxial simple compression so as to consider the friction effect at the die-specimen interface. A method of evaluating the friction coefficient by combining compression tests with the finite element method is presented. The real flow behavior of AA6063 aluminium alloy can be described with sinh-Arrhenius equation. The hot deformation activation energy Q derived from the corrected stress and strain data is 232. 350 kJ/mol.

关键词： Barreling Compression test Friction Flow stress Aluminium alloy Activation energy