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Structural mass prediction in conceptual design of blended-wing-body aircraft

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Chinese Journal of Aeronautics 2019年第11期32卷 2455-2465页

作者： Wensheng ZHU Zhouwei fan Xiongqing yu College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

The Blended-Wing-Body(BWB) is an unconventional configuration of aircraft and considered as a potential configuration for future commercial aircraft. One of the difficulties in conceptual design of a BWB aircraft is structural mass prediction due to its unique structural feature. This paper presents a structural mass prediction method for conceptual design of BWB aircraft using a structure analysis and optimization method combined with empirical calibrations. The total BWB structural mass is divided into the ideal load-carrying structural mass, non-ideal mass, and secondary structural mass. Structural finite element analysis and optimization are used to predict the ideal primary structural mass, while the non-ideal mass and secondary structural mass are estimated by empirical methods. A BWB commercial aircraft is used to demonstrate the procedure of the BWB structural mass prediction method. The predicted mass of structural components of the BWB aircraft is presented, and the ratios of the structural component mass to the Maximum TakeOff Mass(MTOM) are discussed. It is found that the ratio of the fuselage mass to the MTOM for the BWB aircraft is much higher than that for a conventional commercial aircraft, and the ratio of the wing mass to the MTOM for the BWB aircraft is slightly lower than that for a conventional aircraft.

关键词： Aircraft conceptual design Blended-Wing-Body Finite element method Mass prediction Structural optimization

Molybdenum based amorphous and nanocrystalline coatings prepared by high velocity oxy-fuel spraying

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Rare Metals 2012年第4期31卷 355-361页

作者： fan, Zishuan yu, Hongying Wang, Xudong Center for Corrosion and Protection University of Science and Technology BeijingBeijing 100083China

The high velocity oxy-fuel(HVOF) based thermal spray process has developed as a potential advantageous approach for fabricating various kinds of functional *** this article,the coatings of Mo-based alloy were synthesized using the HVOF *** microstructure and the mechanical properties of the HVOF-processed coatings were investigated using SEM,TEM,XRD,and hardness and wear *** treatment was applied to the as-sprayed coatings to develop the microstructure and its effect on the microstructure and mechanical properties of the coatings was *** is found that the HVOF-processed Mo-based alloy coatings are comprised of an amorphous splat matrix embedded with nano-sized crystalline *** at temperatures over 950 ℃ results into crystallization of the amorphous *** mechanical properties of the as-sprayed coatings are enhanced with annealing temperature up to 750 ℃ and from 950 to 1050 ℃,keeps constant between 750 and 950 ℃,and reduce over 1050 ℃.The change of the mechanical property with the microstructure was illustrated in the study.

关键词： molybdenum based alloy coating amorphous and nanocrystalline phases hardness and tribology anealling high velocity oxy-fuel spraying

Fresh human amniotic membrane effectively promotes the repair of injured common peroneal nerve

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Neural Regeneration Research 2019年第12期14卷 2199-2208页

作者： Zhong-yuan Zhang Jin Yang Zhen-Hai fan Da-Li Wang yu-Ying Wang Tao Zhang Li-Mei yu chang-Yin yu Key Laboratory of Cell Engineering in Guizhou Province The Affiliated Hospital of Zunyi Medical University Zunyi Guizhou Province China Department of Thyroid and Breast Surgery Fifth People’s Hospital of Chengdu Chengdu Sichuan Province China The Team of Scientific and Technological Innovation Talents on The Basic and Clinical Research of Amniotic Membrane and Bone Marrow Stem Cells in Guizhou Province Zunyi Guizhou Province China Department of Burn and Plastic Surgery The Affiliated Hospital of Zunyi Medical University Zunyi Guizhou Province China Department of Neurology The Affiliated Hospital of Zunyi Medical University Zunyi Guizhou Province China

Suture and autologous nerve transplantation are the primary therapeutic measures for completely severed nerves. However, imbalances in the microenvironment and adhesion of surrounding tissues can affect the quality of nerve regeneration and repair. Previous studies have shown that human amniotic membrane can promote the healing of a variety of tissues. In this study, the right common peroneal nerve underwent a 5-mm transection in rats. Epineural nerve repair was performed using 10/0 non-absorbable surgical suture. The repair site was wrapped with a two-layer amniotic membrane with α-cyanoacrylate rapid medical adhesive after suture. Hindlimb motor function was assessed using footprint analysis. Conduction velocity of the common peroneal nerve was calculated by neural electrical stimulation. The retrograde axoplasmic transport of the common peroneal nerve was observed using fast blue BB salt retrograde fluorescent staining. Hematoxylin- eosin staining was used to detect the pathological changes of the common peroneal nerve sputum. The mRNA expression of axon regeneration-related neurotrophic factors and inhibitors was measured using real-time polymerase chain reaction. The results showed that the amniotic membrane significantly improved the function of the injured nerve;the toe spread function rapidly recovered, the nerve conduction velocity was restored, and the number of fast blue BB salt particles were increased in the spinal cord. The amniotic membrane also increased the recovery rate of the tibialis anterior muscle and improved the tissue structure of the muscle. Meanwhile, mRNA expression of nerve growth factor, growth associated protein-43, collapsin response mediator protein-2, and brain-derived neurotrophic factor recovered to near-normal levels, while Lingo-1 mRNA expression decreased significantly in spinal cord tissues. mRNA expression of glial-derived neurotrophic factor did not change significantly. changes in mRNA levels were more significant in amniot

关键词： nerve regeneration human amniotic membrane axonal Schwann cells α-cyanoacrylate rapid medical adhesive neural suture tibial anterior muscle neuronal growth factor common peroneal nerve injury neural regeneration

AN ASSIGNMENT METHOD FOR GROUP DECISION MAKING WITH UNCERTAIN PREFERENCE ORDINALS

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Journal of Systems Science and Systems Engineering 2012年第2期21卷 174-183页

作者： Tianhui YOU Zhiping fan Zhuchao yu School of Business Administration Northeastern UniversityShenyang110819China

This paper presents an assignment method to solve the group decision making problem with uncertain preference information. The uncertain preference information is given as uncertain preference ordinals by decision makers. We first address the concept and calculation formulae of preference ordinal frequency, and then, uncertain preference ordinals are transformed into preference ordinal frequencies accordingly. Furthermore, a linear assignment model is built based on the derived preference ordinal frequencies, and the ranking of alternatives can be obtained by solving the model. Finally, a numerical example is used to illustrate the use of the proposed method.

关键词： Group decision making (GDM) uncertain preference ordinal preference ordinal frequency,linear assignment model ranking of alternatives

Dynamic characteristics of a cyclic-periodic structure with a piezoelectric network

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Chinese Journal of Aeronautics 2015年第5期28卷 1426-1437页

作者： Li Lin Deng Pengcheng fan yu School of Energy and Power Engineering Beihang University Collaborative Innovation Center for Advanced Aero-Engine Laboratoire de Tribologie et Dynamique des Systemes Ecole Centrale de Lyon – 36Avenue Guy de Collongues Ecully 69134 France

This paper deals with a cyclic-periodic structure with a piezoelectric network. In such a system, there is not only mechanical connection but also electrical connection between adjacent periodic sectors. The objective is to learn whether the presence of a piezoelectric network would change the dynamic characteristics of the system. The background of the research is about vibration reduction of a bladed disk in an aero-engine, and the system is simulated by a lumped parameter model. The dynamic equations of the system are derived, and then the analytical solution corresponding to the eigenvalue problem is given. The vibration responses to single traveling wave excitations （EO excitations） and multiple traveling wave excitations （NEO excitations） are studied. The results show that the presence of a piezoelectric network would change the natural frequencies of the system compared with those of the system with the piezoelectric shunt circuit. The forced response is sensitive to the connection type and the elements of the network. An energy analysis of the electro-mechanical coupling system has been performed to understand its dynamic behavior, and the following conclusion is obtained： a vibration reduction to excitations whose primary har- monic component is not zero can be achieved by a parallel piezoelectric network, while a reduction to other excitations should be based on a series piezoelectric network.

关键词： Cyclic-periodic structures Electro-mechanical dynamicbehavior Energy analysis Piezoelectric networks Vibration reduction

Enhanced Crystallization of Poly(butylene adipate-co-terephthalate)by a Self-assembly Nucleating Agent

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Chinese Journal of Polymer Science 2024年第5期42卷 663-674,I0010页

作者： Cheng Zhou Kun Chen Zi-Heng Zhang Meng-fan Jing Chun-Tai Liu chang-yu Shen Ya-Ming Wang State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Poly(butylene adipate-co-terephthalate)(PBAT)is a promising biodegradable flexible polymer but suffers from slow crystallization rate,making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene(LDPE).This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide(OMBH).PBAT/OMBH composites with various OMBH contents(0 wt%,0.5 wt%,0.7 wt%,1 wt%,2 wt%,3 wt%and 5 wt%)were prepared through *** effect of OMBH on the crystallization behavior,morphologies and mechanical properties of PBAT was *** highest nucleation efficiency value of 59.6%was achieved for PBAT with 0.7 wt%OMBH,much higher than that of 22.7%for PBAT with 0.7 wt%*** force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of *** transform infrared spectroscopy(FTIR)combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N—H…O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of *** presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical *** work is essential for preparing PBAT with high crystallization rate,enhancing its potential applications in injection-molded products.

关键词： Poly(butylene adipate-co-terephthalate) Biodegradable Self-assembly nucleating agent Crystallization

Accelerated glacier mass loss in the mid-latitude Eurasia from 2019 to 2022 revealed by ICESat-2

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Advances in Climate change Research 2024年第5期15卷 815-829页

作者： Gen-yu WANG chang-Qing KE yu-Bin fan Xiao-Yi SHEN yu CAI Vahid NOURANI Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural ResourcesSchool of Geography and Ocean ScienceNanjing UniversityNanjing 210023China Collaborative Inovation Centerof Novel Sofiware Technology and Industrialization Nanjing 20023China Collaborative Innovation Center of South China Sea Studies Nanjing 210023China School of Earth Sciences and Engineering Hohai UniversityNanjing 210024.China Center of Excellence in Hydroinformatics and Faculty of Civil Engineering University of TabrizTabriz 51368Iran Faculty of Civil and Environmental Engineering Near East UniversityNicosia 99138Turkey

The dynamics of glaciers serve as one of the most important indicators of climate *** current research has primarily concentrated on long-term interannual glacier mass balance and its response to climate change,glaciers may respond more rapidly to climate change,highlighting the urgent need for intra-annual mass balance *** seasonal or short-term variations in glacier mass balance not only enhances our understanding of the interactions between glaciers and the climate system but also provides crucial data for water resource management and ecological *** ICESat-2 and NASADEM datasets were used to estimate the inter-and intra-annual glacier mass balance changes in the mid-latitude Eurasia from 2019 to ***,the response of glacier mass balance to regional air temperature and precipitation values was analysed using ERA5-Land data and multiple regression analysis,*** 2019 to 2022,glacier mass loss in mid-latitude Eurasia reached-45.02±34.21 Gt per year,contributing to a global sea-level rise of 0.12±0.09 mm per *** glacier melt rate in the study area from 2019 to 2022 was 2.33 times higher than that from 2000 to *** the exception of the Western Kunlun region,which experienced a weak accumulation rate of 0.04±0.35 m *** year,all other areas experienced ablation *** mass balance responds differently to temperature and precipitation variations across seasons:higher temperatures in different seasons lead to more negative mass balances,while increased winter and spring precipitation can slow down glacier *** temperature dominates the glacier mass balance changes in the study *** intense heat in 2022 raised average glacier temperatures by 1.04°C compared to 2019-2021,resulting in a more negative mass balance and an increased ice loss of-0.34±1.01 m *** year(-35.07±103.22 Gt per year).This analysis indicates that glacier mass balance is highly sensitive to climate chan

关键词： Glacier mass balance ICESat-2 NASADEM The mid-latitude Eurasia Temperature

Robust Collaborative Optimization Method Based on Dual-response Surface

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 169-176页

作者： WANG Wei fan Wenhui chang Tianqing yuAN yuming National CIMS Engineering Research Center Tsinghua University Beijing 100084 China Department of Control Engineering Academy of Armored Force Engineering Beijing 100072 China

A novel method for robust collaborative design of complex products based on dual-response surface （DRS-RCO） is proposed to solve multidisciplinary design optimization （MDO） problems under uncertainty. Collaborative optimization （CO） which decomposes the whole system into a double-level nonlinear optimization problem is widely accepted as an efficient method to solve MDO problems. In order to improve the quality of complex product in design process, robust collaborative optimization （RCO） is developed to solve those problems under uncertain conditions. RCO does optimization on the linear sum of mean and standard deviation of objective function and gets an optimal solution with high robustness. Response surfaces method is an important way to do approximation in robust design. DRS-RCO is an improved RCO method in which dual-response surface replaces system uncertainty analysis module of CO. The dual-response surface is the approximate model of mean and standard deviation of objective function respectively. In DRS-RCO, All the information of subsystems is included in dual-response surfaces. As an additional item, the standard deviation of objective function is added to the subsystem optimization. This item guarantee both the mean and standard deviation of this subsystem is reaching the minima at the same time. Finally, a test problem with two coupled subsystems is conducted to verify the feasibility and effectiveness of DRS-RCO.

关键词： multidisciplinary design optimization robust design dual-response surface

Room temperature compressive properties and strengthening mechanism of Mg96.17Zn3.15Y0.50Zr0.18 alloy solidified under high pressure

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Journal of Rare Earths 2020年第6期38卷 657-664页

作者： Xiaoping Lin Zhibin fan chang Xu Kunyu Guo chang Xu Shiqi Guo School of Materials and Engineering Northeast UniversityShenyang 110819China School of Resources and Materials Northeast University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Qinhuangdao 066004China

The microstructures of Mg96.17Zn3.15Y0.50Zr0.18 alloys solidified under 2-6 GPa high pressure were investigated by employing SEM(EDS) and *** strengthening mechanism of experimental alloy solidified under high pressure is also discussed by analyzing the compressive properties and compression fracture *** results show that the microstructure of experimental alloy becomes significantly fine-grained with increasing GPa level high pressure during solidification process,and the secondary dendrite arm spacing reduces from 40 μm at atmospheric pressure to 10 μm at 6 GPa *** morphology of the second phases changes from the net structure by the lamellar-type eutectic structure at atmospheric pressure to discontinuous thin rods or particles at 6 GPa ***,the solid solubility of Zn in the Mg matrix is improved with the increase of the solidification *** with atmospheric-pressure solidification,high-pressure solidification can improve the strength of the experimental *** compressive stre ngth is improved from 263 to 437 MPa at 6 *** fracture mechanism of the experimental alloy changes from cleavage fracture at atmospheric pressure to quasi-cleavage fracture at high *** main mechanism of the strength improvement of the experimental alloy includes the grain refinement strengthening caused by the refinement of the solidification microstructure,the second phase strengthening caused by the improvement of the morphology and distribution of the second phases,and solid solution strengthening caused by the increase of the solid solubility of Zn in the Mg matrix.

关键词： High-pressure solidification Mg96.17Zn3.15Y0.50Zr0.18 alloys Secondary dendrite arm spacing Solid solubility Rare earths