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Deep-learning-assisted online surface roughness monitoring in ultraprecision fly cutting

Science China(Technological Sciences) 2024年第5期67卷 1482-1497页

作者： SHEHZAD Adeel RUI XiaoTing DING YuanYuan ZHANG JianShu CHANG Yu LU HanJing chen yiheng Institute of Launch Dynamics Nanjing University of Science and TechnologyNanjing210094China National Key Laboratory of Complex Multibody System Dynamics Nanjing210094China Automotive Engineering Centre University of Engineering and TechnologyLahore54890Pakistan School of Science Nanjing University of Science and TechnologyNanjing210094China College of Engineering Peking UniversityBeijing100871China

Surface roughness is one of the most critical attributes of machined components,especially those used in high-performance *** surface roughness monitoring offers advancements comparable to post-process inspection methods,reducing inspection time and costs and concurrently reducing the likelihood of ***,online monitoring approaches for surface roughness are constrained by several limitations,including the reliance on handcrafted feature extraction,which necessitates the involvement of human experts and entails time-consuming ***,the prediction models trained under one set of cutting conditions exhibit poor performance when applied to different experimental *** address these challenges,this work presents a novel deep-learning-assisted online surface roughness monitoring method for ultraprecision fly cutting of copper workpieces under different cutting *** acceleration signals were acquired during each cutting experiment to develop two datasets,and no handcrafted features were *** deep learning models were developed and evaluated using standard performance metrics.A convolutional neural network stacked on a long short-term memory network outperformed all other network models,yielding exceptional results,including a mean absolute percentage error as low as 1.51%and an R2value of 96.6%.Furthermore,the robustness of the proposed model was assessed via a validation cohort analysis using experimental data obtained using cutting parameters different from those previously *** performance of the model remained consistent and commendable under varied conditions,asserting its applicability in real-world scenarios.

关键词： online surface roughness monitoring UPFC deep learning CNN-LSTM vibration signal

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Tool-tip vibration prediction based on a novel convolutional enhanced transformer

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International Journal of Mechanical System Dynamics 2024年第1期4卷 34-47页

作者： Adeel Shehzad Xiaoting Rui Yuanyuan Ding Yu Chang Jianshu Zhang Hanjing Lu yiheng chen Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjingChina Automotive Engineering Centre University of Engineering&TechnologyLahorePakistan School of Science Nanjing University of Science and TechnologyNanjingChina College of Engineering Peking UniversityBeijingChina

Superior surface finish remains a fundamental criterion in precision machining operations,and tool-tip vibration is an important factor that significantly influences the quality of the machined ***-based models heavily rely on assumptions for model simplification when applied to complex high-end ***,these assumptions may come at the cost of compromising the model's *** contrast,data-driven techniques have emerged as an attractive alternative for tasks such as prediction and complex system *** exploit the advantages of data-driven models,this study introduces a novel convolutional enhanced transformer model for tool-tip vibration prediction,referred to as *** effectiveness of this model is demonstrated through its successful application in ultra-precision fly-cutting(UPFC)*** distinct variants of the model,namely,guided and nonguided CeT-TV,were developed and rigorously tested on a data set custom-tailored for UPFC *** results reveal that the guided CeT-TV model exhibits outstanding performance,characterized by the lowest mean absolute error and root mean square error ***,the model demonstrates excellent agreement between the predicted values and the actual measurements,thus underlining its efficiency and potential for predicting the tool-tip vibration in the context of UPFC.

关键词： tool-tip vibration ultraprecision fly cutting data-driven modeling transformer

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SURFACE EFFECT ON NANOSIZED VOID GROWTH IN A RIGID-PERFECTLY PLASTIC MATERIAL

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Acta Mechanica Solida Sinica 2008年第1期21卷 9-14页

作者： Tong Hui yiheng chen School of Aerospace MOE Xi＇an Jiaotong University Xi＇an 710049 China

The influence of the surface effect on the nanosized spherical void growth in a rigidperfectly plastic material is analyzed and the mechanism of the nanosized void growth with high triaxiality is given. Based on the Rice and Tracey model for a macro void growth, the present model is proposed to account for the nanosized void growth under a uniform remote strain rate field with consideration on the surface effect. It is concluded that the surface effect yields an evident resistant influence on the nanosized void growth. That is, this influence decays as the void radius increases. With high triaxiality, the nanosized void growth is divided into two stages： the initial stage and the mature stage. At the first stage, the void grows slowly and the influence of surface effect is relatively weak, whereas at the second stage, the influence is significant and the void grows drastically.

关键词： nanosized void extended variational principle void growth surface effect high triaxiality

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基于AIS数据的长三角沿海地区船舶碳排放估算与分析

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环境科学学报 2024年第8期44卷 83-97页

作者：蔡欣宇陈焱明陈奕恒汪峰崔越尹昌贵河海大学地球科学与工程学院南京211100 河海大学江苏省水资源环境遥感监测评估工程研究中心南京211100 国家海洋信息中心天津300171 南京信息工程大学商学院南京210044 南京信息工程大学气候经济与低碳产业研究院南京210044

长三角地区涵盖上海、江苏、浙江和安徽,作为中国经济腾飞的关键推动力,在我国的经济繁荣中发挥着至关重要的作用.随着经济的快速发展,碳排放问题逐渐显现,其中,船舶碳排放成为环境挑战的一项重要议题.船舶自动识别系统(AIS)数据作为记... 详细信息

长三角地区涵盖上海、江苏、浙江和安徽,作为中国经济腾飞的关键推动力,在我国的经济繁荣中发挥着至关重要的作用.随着经济的快速发展,碳排放问题逐渐显现,其中,船舶碳排放成为环境挑战的一项重要议题.船舶自动识别系统(AIS)数据作为记录船舶活动的有力工具,提供了精确量化碳排放的手段.本文利用2016年AIS船舶数据,借助船舶交通排放评估模型(Steam)对长三角周边海域的全年船舶碳排放量进行精细估算,并从船舶类型、排放源、航行状态等时空角度对全年碳排放特征进行详尽分析.结果显示,2016年长三角沿海区域的二氧化碳总排放量估计为1258万t,其中,货船贡献了67%的碳排放,而巡航和低速巡航状态下的船舶碳排放量占长三角沿海区域水域碳总排放量的1/2以上.船舶碳排放的变化趋势与季节性、气候和社会等多种因素密切相关.由于春节期间贸易活动相对减少,航运需求下降,船舶运输量减少,因此,1—2月的碳排放量最低,大约分别为78万t和56万t.而9—11月气候适宜,航运需求增大,这几个月的船舶活动最为明显,其中,10月达到全年船舶碳排放的高峰,大约为145万t.长三角沿海区域碳排放量较高的主要区域大多位于港口地带,尤其是上海港、宁波舟山港及长江口区域的碳排放最为显著.本研究对长三角沿海区域船舶碳排放的规律进行了深入剖析,为加深对该问题的理解和采取有效措施应对船舶碳排放问题提供了有益的参考和指导.这项研究不仅为未来相关研究奠定了基础,还可用于与历史或未来的船舶排放数据进行比较,并为制定船舶排放监管行动提供支持.

关键词：船舶碳排放长三角沿海地区 AIS数据时空分析

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CONSERVATION LAWS IN FINITE MICROCRACKING BRITTLE SOLIDS

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Acta Mechanica Solida Sinica 2005年第3期18卷 189-199页

作者： Wang Defa chen yiheng Fukui Takuo Department of Civil Engineering Xi＇an University of Technology Xi＇an 710048 China Department of Engineering Mechanics Xi＇an Jiaotong University Xi＇an 710049 China Department of Architecture and Civil Engineering Fukui University Fukui 910-8507 Japan

This paper addresses the conservation laws in finite brittle solids with microcracks. The discussion is limited to the 2-D cases. First, after considering the combination of the Pseudo-Traction Method and the indirect Boundary Element Method, a versatile method for solving multi-crack interacting problems in finite plane solids is proposed, by which the fracture parameters （SIF and path-independent integrals） can be calculated with a desirable accuracy. Second, with the aid of the method proposed, the roles the conservation laws play in the fracture analysis for finite microcracking solids are studied. It is concluded that the conservation laws do play important roles in not only the fracture analysis but also the analysis of damage and stability for the finite microcracking system. Finally, the physical interpretation of the M-integral is discussed further. An explicit relation between the M-integral and the crack face area, i.e., M = GS, has been discovered using the analytical method, which can shed some light on the Damage Mechanics issues from a different perspective.

关键词： conservation laws finite microcracking solids pseudo-traction method boundary element method stress intensity factors

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Improved incremental transfer matrix method for nonlinear rotor-bearing system

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Acta Mechanica Sinica 2020年第5期36卷 1119-1132,I0004页

作者： yiheng chen Xiaoting Rui Zhiyong Zhang Adeel Shehzad Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjing 210094China Department of Industrial and Manufacturing Engineering University of Engineering and TechnologyLahore 54000Pakistan

Rotor system supported by nonlinear bearing such as squeeze film damper(SFD)is widely used in practice owing to its wide range of damping capacity and simplicity in *** this paper,an improved and effective Incremental transfer matrix method(ITMM)is first presented by combining ITMM and fast Fourier transform(FFT).Afterwards this method is applied to calculate the dynamic characteristics of a Jeffcott rotor system with *** convergence dificulties incurred caused by strong nonlinearities of SFD has been dealt by adopting a control *** is found that for the more general boundary problems where the boundary conditions are not at input and output ends of a chain system,the supplementary equation is necessarily ***,the Floquet theory is used to analyze the stability and bifurcation type of the obtained periodic *** semi-analytical results,including the periodic solutions of the system,the bifurcation points and their types,are in good agreement with the numerical ***,the involution mechanism of the quasi-periodic and chaotic motions near the first-order translational mode and the second order bending mode of this system is also clarified by this method with the aid of Floquet theory.

关键词： Incremental transfer matrix method Squeeze film damper Jeffcott rotor system Bifurcation Nonlinear characteristics

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THE EXPLICIT FORMULATIONS FOR THE L-INTEGRAL

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Acta Mechanica Solida Sinica 1999年第1期12卷 74-82页

作者： Shi Junping Liu Xiehui chen yiheng Xian Univ Technol Dept Engn Mech Xian 710048 Peoples R China Xian Jiao Tong Univ Sch Civil Engn & Mech Xian 710049 Peoples R China

In this paper, a simple but inberent relation between theL-integral and the Buekner work conjugate integral is proved forcrack problems in isotropic, anisotropic, and dissimilar materi- als,respectively. It is found that, in the above-mentioned three cases,the L-integral, from the math- ematical point of view as well as inprinciple, arises from Betti's reciprocal theorem. This means thatthe Bueckner work conjugate integral is a more generalpath-independent integral than the others since any otherpath-independent integrals could be derived by using the Buecknerintegral while choosing a different subsidiary stress-displacementfield.

关键词： integral work conjugate integral crack

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基于通信时延概率分布的虚拟编组技术研究

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应用技术学报 2024年第1期24卷 117-122页

作者：邹劲柏陈一衡许哲谱上海应用技术大学轨道交通学院上海201418

轨道交通车车通信作为列车虚拟编组系统中的关键环节,深刻影响着虚拟编组状态下列车间的协调运行。在分析通信时延概率分布特征的基础上,探讨了通信延误对列车虚拟编组的影响,为车车通信系统性能设计提供理论支撑。提出一种列车动力学模... 详细信息

轨道交通车车通信作为列车虚拟编组系统中的关键环节,深刻影响着虚拟编组状态下列车间的协调运行。在分析通信时延概率分布特征的基础上,探讨了通信延误对列车虚拟编组的影响,为车车通信系统性能设计提供理论支撑。提出一种列车动力学模型,利用模型预测控制(MPC)的方法实现多列车间的虚拟编组协调运行控制。通过该模型仿真实验分析不同概率分布情况下的通信时延对虚拟编组列车控制系统的影响。实验结果表明,较大的通信时延扰动将加剧虚拟编组系统的振荡,这些问题将给列车的平稳运行与节能带来挑战。

关键词：虚拟编组模型预测控制车车通信时延

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AN INVESTIGATION ON STRESS INTENSITY FACTORS OF INTERFACE CRACK FOR THREE TYPES OF SPECIMENS

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Acta Mechanica Solida Sinica 2000年第1期13卷 42-49页

作者： Shi Junping Liu Xiehui Mo Xiaoyi chen yiheng Department of Engineering Mechanics Xi'an Universiry of TechnologyXi'an 710048China School of Civil Eingineering and Mechanics Xi'an Jiaotong UniversityXi'an 710049China

The problems of finite bimaterial plates, hearing uniform tension, compact: tension and three point bending, are studied by using the eigenfunction expansion variation method (EEVM). And interfacial stress intensity factors (SIFs) are determined. The SIFs varying with shear modulus mu and Poisson's ratios nu of both materials are discussed.

关键词： bimaterial eigenfunction expansion interface crack stress intensity factors

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Analysis of a permeable interface crack in elastic dielectric/piezoelectric bimaterials

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Acta Mechanica Sinica 2007年第6期23卷 681-687页

作者： Qun Li yiheng chen School of Aerospace,Xi’an Jiaotong University,Xi’an 710049,China School of Aerospace Xi’an Jiaotong University

A permeable interface crack between elasticdielectric material and piezoelectric material is studied basedon the extended Stroh’s *** by strong engi-neering demands to design new composite materials,theauthors perform numerical analysis of interface crack tip sin-gularities and the crack tip energy release rates for 35 typesof dissimilar bimaterials,respectively,which are constructedby five kinds of elastic dielectric materials:Epoxy,Poly-mer,Al;O;.SiC,and Si;N;and seven kinds of practicalpiezoelectric ceramics:PZT-4,BaTiO;,PZT-5H,PZT-6B,PZT-7A,P-7,and PZT-PIC 151,*** elasticdielectric material with much smaller permittivity than com-mercial piezoelectric ceramics is treated as a special trans-versely isotropic piezoelectric material with extremely *** present investigation shows that thestructure of the singular field near the permeable interfacecrack tip consists of three singularities:r;and r;,which is quite different from that in the impermeable inter-face *** can be concluded that different far field load-ing cases have significant influence on the near-tip fracturebehaviors of the permeable interface *** on thepresent theoretical treatment and numerical analysis,the elec-tric field induced crack growth is well explained,which pro-vides a better understanding of the failure mechanism inducedfrom interface crack growth in elastic dielectric/piezoelectricbimaterials.

关键词： Elastic dielectric Piezoelectric Permeable Interface crack Singularity Energy release rate

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