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数字通信世界 2024年第4期 49-51页

作者：孟宪明安徽皖通科技股份有限公司安徽合肥230000

在大数据时代背景下,利用大数据技术构建环境污染监测系统的优势在于可以将大量的数据源整合在一起,通过分析这些数据,实现更加准确、及时地进行环境污染监测和管理,从而为环境保护工作提供了有力的支持。基于此,文章重点研究基于大数... 详细信息

在大数据时代背景下,利用大数据技术构建环境污染监测系统的优势在于可以将大量的数据源整合在一起,通过分析这些数据,实现更加准确、及时地进行环境污染监测和管理,从而为环境保护工作提供了有力的支持。基于此,文章重点研究基于大数据架构的环境污染精准监测与决策平台的建设,旨在促进企业绿色生产,保护生态环境。

关键词：大数据架构环境污染精准监测决策平台建设

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铆接铝合金板铆钉失效缺陷检测方法研究

汽车工程 2024年第2期46卷 366-374页

作者：刘凉张滢史晨阳赵新华孟宪明刘增昌天津理工大学天津市先进机电系统设计与智能控制重点实验室天津300384 中国汽车技术研究中心有限公司天津300300 中国汽车工业工程有限公司天津300113

针对车身用铝合金板内部铆钉缺陷特征提取难度大、缺陷类型与程度识别准确率低的问题,提出一种基于高斯卷积深度信念网络与双向长短期记忆网络相结合的铆钉失效缺陷诊断模型与检测方法。首先,面向5种铆钉断裂缺陷设计试件并搭建自动检... 详细信息

针对车身用铝合金板内部铆钉缺陷特征提取难度大、缺陷类型与程度识别准确率低的问题,提出一种基于高斯卷积深度信念网络与双向长短期记忆网络相结合的铆钉失效缺陷诊断模型与检测方法。首先,面向5种铆钉断裂缺陷设计试件并搭建自动检测系统,通过规划和调整探头姿态有效地降低提离效应对检测信号的影响。其次,设计双网络融合诊断模型提取和学习多维度缺陷特征信息,解决检测曲线中由时序变化特性和空间分布状态表征的缺陷信息提取难题。实验结果表明,与传统卷积网络及单一深度信念网络相比,优化后算法诊断模型的平均准确率为99.85%,相比提升了14.54%,且具有良好的通用性和鲁棒性,可实现铆钉内部缺陷的在线诊断。

关键词：铆钉内部缺陷检测系统模式识别特征融合

基于临界剪应变势差的复合材料层间失效参数标定及冲击模型建立

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汽车工艺与材料 2024年第10期 1-9页

作者：宋通张赛孟宪明中国汽车技术研究中心有限公司天津300300

提出了一种应用于校准和验证碳纤维增强复合材料(CFRP)层压板分层相关的层间参数标定方法及基于*MAT_58的冲击模型。层间参数标定方面,主要利用短梁剪切试验面外剪应变与正应变云图提取层间失效条件下的临界剪应变势差计算复合材料层间... 详细信息

提出了一种应用于校准和验证碳纤维增强复合材料(CFRP)层压板分层相关的层间参数标定方法及基于*MAT_58的冲击模型。层间参数标定方面,主要利用短梁剪切试验面外剪应变与正应变云图提取层间失效条件下的临界剪应变势差计算复合材料层间剪切强度。进一步对材料进行10J和200J能量水平的落锤冲击试验和叠层壳及细化网格尺寸模拟,以验证层间参数的有效性和建模实用性。结果表明,P16M2模型分层阈值载荷误差为5.09%,峰值力误差为8.99%,证明了层间参数的有效性,同时根据各模型在仿真精度及计算成本方面表现,增加叠层壳的层数较细化网格尺寸更为有效。

关键词：复合材料层压板分层失效短梁剪切落锤冲击有限元分析

Fracture behavior of 304 stainless steel coatings by cold gas dynamic spray

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Acta Metallurgica Sinica(English Letters) 2011年第3期24卷 249-254页

作者： Wei HAN xianming meng Jie ZHAO Junbao ZHANG School of Materials Science and Engineering Dalian University of Technology Dalian 116085 China Baosteel Research Institute Baoshan Iron & Steel Co. Ltd. Shanghai 201900 China

304 stainless steel coating was deposited on the Interstitial-Free steel substrate by cold gas dynamic spraying （CGDS）. Three-point bending test of the cold sprayed 304 stainless steel coating was tested by SHIMADZU electro-hydraulic servo-controlled fatigue testing machine and the fracture morphology was examined by scanning electron microscopy. The results showed that the fracture behavior of the cold sprayed 304 stainless steel coating was brittleness fracture. The crack in the coating occurred in the interfaces between particles and the crack extended to the internal of the coating with the increase of the load. When the crack has extended to the combination interface between coating and substrate, the crack extended to the two sides. The microstructure and mechanical property of the cold sprayed 304 stainless steel coating have been optimized after heat treatment.

关键词： Cold gas dynamic spraying 304 stainless steel coating Three- point bending test Fracture behavior Heat treatment

Influence of annealing treatment on microstructure and properties of cold sprayed stainless steel coatings

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Acta Metallurgica Sinica(English Letters) 2011年第2期24卷 92-100页

作者： xianming meng Junbao ZHANG Jie ZHAO Wei HAN Yongli LIANG School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China Baosteel Research Institute Baoshan Iron & Steel Co. Ltd. Shanghai 201900 China

304 stainless steel coatings had been deposited on carbon-steel substrate by cold spray technique, vacuum annealing treatment was applied to the coatings with different temperatures, and the influence of annealing treatment on the microstructure and electrochemical behavior of the coatings in 3.5% NaCl were analyzed. The results indicated that, the cold sprayed coating was constituted by the flattened particles, and the interfaces were clearly observed between the deposited particles. It was also found that annealing treatment led to the recovery and recrystallization of the elongated grains in the as-sprayed coatings with the increase of annealing temperature. When the annealing temperature achieved to 950 ？ C, the interface of particles was disappeared and the coating s structure was made of new recrystallization austenite grains. Annealing treatment increased the potential volts, and reduced the corrosion rate with the increase of annealing temperature. The electrical corrosion morphology indicated that, the corrosion was firstly at the distortion area and the crevice corrosion mechanism played an important part. Based on these results, processes active during annealing treatment are kinetically dependent and strongly influenced by the annealing treatment temperature.

关键词： Cold spray 304 stainless steel coating Annealing treatment Corrosion behavior

Influence of Gas Temperature on Microstructure and Properties of Cold Spray 304SS Coating

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Journal of Materials Science & Technology 2011年第9期27卷 809-815页

作者： xianming meng Junbao Zhang Jie Zhao Yongli Liang Yujun Zhang School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China Baosteel Research Institute Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

In the present study, 304 stainless steel coatings were deposited on interstitial-free steel substrates by cold gas dynamic spray technology. The effect of gas temperature on microstructure, micro-hardness, cohesive strength, and electrochemical property of the coatings were investigated and compared. The results showed that increasing gas temperature had a great contribution to enhancing the bonding strength between the deposited particles and making the microstructure more density. Therefore, the porosity of the coatings decreased from 0%4-0.5% to 2%4-0.3%, and the tensile strength of the coatings increased from 564-4 MPa up to 734-3 MPa. In addition, the corrosion resistance of the coatings was also deeply influenced by process gas temperature. The corrosion kinetics of the coatings were affected by both of the plastic deformation of deposited particles and the porosity in the coatings.

关键词： Cold spray Gas temperature 304 stainless steel coating Microstructure Property

Microstructure and nano-mechanical property of cold spray Co-base refractory alloy coating

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Acta Metallurgica Sinica(English Letters) 2011年第3期24卷 190-194页

作者： Vongli LIANG Bi SHI Xiaoping YANG Junbao ZHANG xianming meng Advanced Technology Institute Baosteel Technology Center Baoshan Iron & Steel Co. Shanghai 201900 China School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

Co-base refractory alloy coating was prepared on carbon steel substrate by cold spray technology; microstructure and nano-mechenieal property were examined by scanning electron microscope （SEM） and nano indenter individually. The results showed that about 250 μm Co-base refractory alloy coating could be deposited o11 steel substrate by cold spray technique, interface between coating and substrate was combined well, and the refractory alloy particle had a significant plastic deformation during deposition process; mixing Ni powders into Co-base refractory alloy powders could increase the density and decrease the nano-hardness of coating, the nano-hardness and elastic modulus of refractory alloy coating was higher than 6 GPa and 160 GPa, respectively.

关键词： Cold spray Co-base refractory alloy Microstructure Nano-mechanical property

基于PAM-RTM的CFRP平板RTM工艺及孔隙缺陷仿真

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工程塑料应用 2024年第3期52卷 76-82页

作者：邹文涛孟宪明程从前宋通张赛曹铁山吴昊赵杰大连理工大学材料科学与工程学院辽宁大连116024 中国汽车技术研究中心有限公司天津300162

树脂传递模塑(RTM)成型过程中不同工艺参数对碳纤维增强树脂基复合材料(CFRP)构件质量和性能有极大影响。为了精准设计RTM成型参数,降低最终构件的孔隙缺陷含量,分析充模过程中两种尺度孔隙率的变化及在构件中的分布规律,基于PAM-RTM软... 详细信息

树脂传递模塑(RTM)成型过程中不同工艺参数对碳纤维增强树脂基复合材料(CFRP)构件质量和性能有极大影响。为了精准设计RTM成型参数,降低最终构件的孔隙缺陷含量,分析充模过程中两种尺度孔隙率的变化及在构件中的分布规律,基于PAM-RTM软件对CFRP平板模型RTM成型的充模及双尺度孔隙形成进行了仿真模拟。分析了不同树脂黏度、浇注压力对填充时间及宏观和微观孔隙分布、孔隙率的影响规律;在构件中选取了不同位置的横向轴线并对比轴上宏观/微观孔隙的含量及分布特征,分析随着距离浇注口位置变化孔隙率的变化规律。结果表明,在恒压浇注条件下,浇注压力越大,树脂黏度越小,填充时间越短;树脂黏度为0.1Pa·s、浇注压力为1.5MPa时,充模时间最小,为13.11s。宏观孔隙率随浇注压力升高而减小,微观孔隙率则相反。宏观孔隙在开始填充一段时间后形成,孔隙率最终在出胶口达到最大值;微观孔隙则在填充初始阶段开始形成,孔隙率随着填充距离增加逐渐减小。3条横向轴上两种尺度孔隙率的变化趋势相近;浇注压力影响宏观孔隙开始形成的位置及微观孔隙结束形成的位置,并影响填充结束时的最大宏观孔隙率和填充开始时的最大微观孔隙率。

关键词：树脂传递模塑双尺度孔隙模型孔隙缺陷 PAM-RTM软件仿真

Revelations from Historical Experiments on Constant Speed of Light

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Journal of Applied Mathematics and Physics 2022年第3期10卷 623-640页

作者： xianming meng Research School of Physics Australian National University Canberra ACT Australia

The postulate of constant speed of light for all reference frames is the foundation of relativity theories. The resultant time dilation and length contraction are generally accepted but still perplexing for most people. By re-examining the historical evidence, this paper confirms Einstein’s postulate and reveals the mechanism for the constant speed of light: the interaction between photons and matter can impart the speed of an inertial frame to the photons and thus result in the same speed of light for different inertial reference frames. This mechanism can consistently explain all major experiments on the constant speed of light.

关键词： Photon Matter Interaction Special Relativity Fizeau Experiment Michelson-Morley Experiment Hoek Experiment Sagnac Experiment