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Chinese Journal of Aeronautics 2024年第6期37卷 392-409页

作者： Ziang JIN Shouzheng SUN Sunil Chandrakant JOSHI zhenyu han Hongya FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in *** the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is *** influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is *** results show that the overall temperature increases and then decreases as the gas flow rate *** the increase in heat transfer distance and laying speed,the overall temperature ***,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer ***,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.

关键词： Fiber reinforced plastics Thermoplastics Heating temperature Automated fiber placement CF/PEEK

Effect of deformation parameters on the austenite dynamic recrystallization behavior of a eutectoid pearlite rail steel

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 833-841页

作者： Haibo Feng Shaohua Li Kexiao Wang Junheng Gao Shuize Wang Haitao Zhao zhenyu han Yong Deng Yuhe Huang Xinping Ma Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China Institute for Steel Sustainable Technology Liaoning Academy of MaterialsShenyang 110004China Pangang Group Panzhihua Iron and Steel Research Institute Co.Ltd. Panzhihua 617000China

Understandings of the effect of hot deformation parameters close to the practical production line on grain refinement are crucial for enhancing both the strength and toughness of future rail *** this work,the austenite dynamic recrystallization(DRX)behaviors of a eutectoid pearlite rail steel were studied using a thermo-mechanical simulator with hot deformation parameters frequently employed in rail production *** single-pass hot deformation results reveal that the prior austenite grain sizes(PAGSs)for samples with different deformation reductions decrease initially with an increase in deformation ***,once the deformation temperature is beyond a certain threshold,the PAGSs start to *** can be attributed to the rise in DRX volume fraction and the increase of DRX grain with deformation temperature,***-pass hot deformation results show that the accumulated strain generated in the first and second deformation passes can increase the extent of *** the case of complete DRX,PAGS is predominantly determined by the deformation temperature of the final *** suggests a strategic approach during industrial production where part of the deformation reduction in low temperature range can be shifted to the medium temperature range to release rolling mill loads.

关键词： eutectoid pearlite rail steel prior austenite grain size dynamic recrystallization single-pass hot deformation three-pass hot deformation

Dynamic mechanical properties and wave propagation of composite rock-mortar specimens based on SHPB tests

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International Journal of Mining Science and Technology 2022年第4期32卷 793-806页

作者： zhenyu han Diyuan Li Xibing Li School of Resources and Safety Engineering Central South UniversityChangsha 410083China School of Civil Engineering Southeast UniversityNanjing 210096China Department of Civil Engineering Monash UniversityMelbourneVictoria 3800Australia

Filled inclusions in rock discontinuities play a key role in the mechanical characteristics of the rock and thereby influence the stability of rock engineering. In this study, a series of impact tests were performed using a split Hopkinson pressure bar system with high-speed photography to investigate the effect of interlayer strength on the wave propagation and fracturing process in composite rock-mortar *** results indicate that the transmission coefficient, nominal dynamic strength, interlayer closure, and specific normal stiffness generally increase linearly with increasing interlayer stiffness. The cement mortar layer can serve as a buffer during the deformation of composite specimens. The digital images show that tensile cracks are typically initiated at the rock-mortar interface, propagate along the loading direction, and eventually result in a tensile failure regardless of the interlayer properties. However, when a relatively weaker layer is sandwiched between the rock matrix, an increasing amount of cement mortar is violently ejected and slight slabbing occurs near the rock-mortar interface.

关键词： Rock dynamics Wave propagation Rock-mortar Stiffness Energy Fracturing

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涡流冷却静电润滑复合干式钻削技术研究

机床与液压 2024年第6期52卷 74-80页

作者：张晏晴吕海峰韩占龙韩振宇陈桂涛中北大学机械工程学院山西太原030051 上海凌云工业科技有限公司上海201708

为降低机械加工过程中切削液对环境造成的污染以及处理切削液时高昂的成本,提出一种兼有涡流冷却效应和静电润滑效应的干式钻削技术与装置。将气体离子化、臭氧化后吹到切削加工区域,代替切削液实现润滑、冷却的作用,获得良好的断屑效果... 详细信息

为降低机械加工过程中切削液对环境造成的污染以及处理切削液时高昂的成本,提出一种兼有涡流冷却效应和静电润滑效应的干式钻削技术与装置。将气体离子化、臭氧化后吹到切削加工区域,代替切削液实现润滑、冷却的作用,获得良好的断屑效果,同时延长刀具的寿命。基于结构参数对系统放电性能、臭氧浓度以及冷却效果的影响规律,优化装置结构,形成干式辅助钻削装置。实验结果表明:当电极锥度为15°、电极直径为1 mm、铜帽内径为3 mm、气体流量为20 L/min、驱动电压为6 kV时,臭氧浓度达到峰值34.2×10^(-6)。通过与纯干式切削对比发现:所提技术的切削温度降低40.9%,刀具刃口基本没有损伤,切屑微观表面切痕分布清晰、条理均匀。所设计的涡流冷却静电润滑干式钻削技术在切削效应、冷却效果、刀具磨损以及切屑形态等方面均优于传统的干式钻削技术,可以用于六系铝材的钻削加工。

关键词：静电润滑涡流冷却干式钻削技术

Fire and Corrosion Resistances of Intumescent Nano-coating Containing Nano-SiO_2 in Salt Spray Condition

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Journal of Materials Science & Technology 2010年第1期26卷 75-81页

作者： zhenyu Wang Enhou han Fuchun Liu Wei Ke State Key Laboratory for Corrosion and Protection Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China

The nano-concentrates and flame retardant nano-coating were prepared in thhis study. The effect of nano-SiO2 on the corrosion resistance and fire resistance of ammonium polyphosphate-pentaerythritol-melamine （APP- PER-MEL） coating was investigated by differential thermal analysis （DTA）, scanning electron microscopy （SEM）, effective thermal conductivity （λ/d）, X-ray photoelectron spectroscopy （XPS） and fire protection test. The chemical action and endothermic effect of ammonium polyphosphate, pentaerythritol and melamine in traditional flame retardant coating were damaged by salt spray condition, whereas the flame-retardant additives in the nano-coating demonstrated the good chemical interaction in salt spray condition. The uniformly dispersed nano-SiO2 particles could improve corrosion resistance of the coating, and hence nano-coating could remain the good fire-resistant properties even after 500 h salt spray test.

关键词： Nano-SiO2 APP-PER-MEL coating Nano-coating Salt spray test Fire-resistant property

Abnormal Shape Mould Winding

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Chinese Journal of Aeronautics 2007年第6期20卷 552-558页

作者： Fu Hongya Wang Xianfeng han zhenyu Fu Yunzhong School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China

A theory of composite material patch winding is proposed to determine the winding trajectory with a meshed data model. Two different conditions are considered in this study. One is Bridge condition on the concave surface and the other is Slip line condition in the process of patch winding. This paper presents the judgment principles and corresponding solutions by applying differential geometry theory and space geometry theory. To verify the feasibility of the patch winding method, the winding control code is programmed. Furthermore, the winding experiments on an airplane inlet and a vane are performed. From the experiments, it shows that the patch winding theory has the advantages of flexibility, easy design and application.

关键词： filament winding fiber technology composite material airplane inlet vane

Realization Methodology of a 5-axis Spline Interpolator in an Open CNC System

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Chinese Journal of Aeronautics 2007年第4期20卷 362-369页

作者： Wang Yongzhang Ma Xiongbo Chen Liangji han zhenyu School of Electromechanical Engineering Harbin Institute of Technology Harbin 150001 China

By making use of the advantages of non-uniform rational B-spline （NURBS） curves to represent spatial curves, an instruction format with double NURBS curves suitable for 5-axis coordinated real-time interpolation is presented to replace the current 5-axis coordinated linear interpolation method defective in low-speed, low-accuracy and enormous numerical control （NC） files in sculptured surface machining. A generation procedure of the NC files with the presented format is introduced and the method to realize the interpolation in an open computer numerical control （CNC） system is developed by ourselves. These illustrated the feasibility of the proposed method and its capability of avoiding all the shortages of 5-axis linear interpolation method.

关键词： open CNC system sculptured surface 5-axis machining NURBS interpolation

Thermal Behavior of Nano-TiO_2 in Fire-Resistant Coating

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Journal of Materials Science & Technology 2007年第4期23卷 547-550页

作者： zhenyu WANG Enhou han Fuchun LIU Wei KE Environmental Corrosion Center Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The dispersion state of nano-TiO2 particles was studied by using transmission electron microscopy （TEM）and Fourier transform infrared spectroscopy （FT-IR）. Nanoparticles can be fully dispersed by specific hyperdispersant. The improvement of nano-TiO2 in thermal behavior and flame retardation of acrylic polymer and fire-resistant coating was investigated by differential thermal analysis （DTA）, thermogravimetry （TG）and fire-resistant time test. It is demonstrated that nano-TiO2 is helpful for enhancing the thermal stability,anti-oxidation and fire-resistant properties of acrylic polymer and fire-resistant coating.

关键词： Nano-TiO2 Fire-resistant coating Thermal stability Fire-resistant properties

CMIP6 Evaluation and Projection of Temperature and Precipitation over China

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Advances in Atmospheric Sciences 2021年第5期38卷 817-830页

作者： Xiaoling YANG Botao ZHOU Ying XU zhenyu han Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China National Climate Center China Meteorological AdministrationBeijing 100081China

This article evaluates the performance of 20 Coupled Model Intercomparison Project phase 6(CMIP6)models in simulating temperature and precipitation over China through comparisons with gridded observation data for the period of 1995–2014,with a focus on spatial patterns and interannual *** evaluations show that the CMIP6 models perform well in reproducing the climatological spatial distribution of temperature and precipitation,with better performance for temperature than for *** interannual variability can also be reasonably captured by most models,however,poor performance is noted regarding the interannual variability of winter *** on the comprehensive performance for the above two factors,the“highest-ranked”models are selected as an ensemble(BMME).The BMME outperforms the ensemble of all models(AMME)in simulating annual and winter temperature and precipitation,particularly for those subregions with complex terrain but it shows little improvement for summer temperature and *** AMME and BMME projections indicate annual increases for both temperature and precipitation across China by the end of the 21st century,with larger increases under the scenario of the Shared Socioeconomic Pathway 5/Representative Concentration Pathway 8.5(SSP585)than under scenario of the Shared Socioeconomic Pathway 2/Representative Concentration Pathway 4.5(SSP245).The greatest increases of annual temperature are projected for higher latitudes and higher elevations and the largest percentage-based increases in annual precipitation are projected to occur in northern and western China,especially under ***,the BMME,which generally performs better in these regions,projects lower changes in annual temperature and larger variations in annual precipitation when compared to the AMME projections.

关键词： CMIP6 evaluation and projection temperature precipitation ensemble

CMIP6 Evaluation and Projection of Precipitation over Northern China:Further Investigation

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Advances in Atmospheric Sciences 2023年第4期40卷 587-600页

作者： Xiaoling YANG Botao ZHOU Ying XU zhenyu han Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China Jiangxi Vocational and Technical College of Information Application Nanchang 330043China National Climate Center China Meteorological AdmnistrationBeijing 100081China

Based on 20 models from phase 6 of the Coupled Model Intercomparison Project(CMIP6),this article explored possible reasons for differences in simulation biases and projected changes in precipitation in northern China among the allmodel ensemble(AMME),“highest-ranked”model ensemble(BMME),and“lowest-ranked”model ensemble(WMME),from the perspective of atmospheric circulations and moisture *** results show that the BMME and AMME reproduce the East Asian winter circulations better than the *** with the AMME and WMME,the BMME reduces the overestimation of evaporation,thereby improving the simulation of winter *** three ensemble simulated biases for the East Asian summer circulations are generally similar,characterized by a stronger zonal pressure gradient between the mid-latitudes of the North Pacific and East Asia and a northward displacement of the East Asian westerly ***,the simulated vertical moisture advection is improved in the BMME,contributing to the slightly higher performance of the BMME than the AMME and WMME on summer precipitation in North and Northeast *** to the AMME and WMME,the BMME projects larger increases in precipitation in northern China during both seasons by the end of the 21st century under the Shared Socioeconomic Pathway 5-8.5(SSP5-8.5).One of the reasons is that the increase in evaporation projected by the BMME is *** projection of a greater dynamic contribution by the BMME also plays a *** addition,larger changes in the nonlinear components in the BMME projection contribute to a larger increase in winter precipitation in northern China.

关键词： CMIP6 ensemble evaluation and projection moisture budget atmospheric circulation