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Journal of Iron and Steel Research International 2012年第9期19卷 68-72页

作者： DING Hua 1 , 2 , LI Hua-ying 1 , DING Hao 1 , QIU Chun-lin 2 , TANG Zheng-you 1 ( 1.school of Materials and Metallurgy , northeastern university , shenyang 110819 , Liaoning , China 2.State Key Lab of Rolling and Automation , northeastern university , shenyang 110819 , Liaoning , China ) school of Materials and Metallurgy Northeastern University Shenyang Liaoning China State Key Lab of Rolling and Automation Northeastern University Shenyang Liaoning China

Two steels without and with Nb addition were chosen to investigate the effects of Nb on the microstructures and the mechanical properties of Fe-Mn-Al-Si *** results revealed that Nb refined the grains markedly and both TRIP and TWIP effects occurred during deformation *** Nb containing steel possesses higher yield strength and much lower tensile strength , the latter being explained by the suppression of TRIP effect due to the increase of stacking fault *** indicates grain refining is secondary for strengthening of steels when TRIP or TWIP effect exists during the deformation of low carbon and high Mn steels.

关键词： grain size strength high Mn steel Nb

Generating function approach to reliability analysis of structural systems

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Science China(Technological Sciences) 2009年第10期52卷 2849-2858页

作者： ZHOU JinYu1 & XIE LiYang2 1 Jiangsu Teacher’s university of Technology, Changzhou 213001, China 2 northeastern university, shenyang 110004, China Jiangsu Teacher’s university of Technology Changzhou China northeastern university Shenyang China

The generating function approach is an important tool for performance assessment in multi-state systems. Aiming at strength reliability analysis of structural systems, generating function approach is introduced and developed. Static reliability models of statically determinate, indeterminate systems and fatigue reliability models are built by constructing special generating functions, which are used to describe probability distributions of strength (resistance), stress (load) and fatigue life, by defining composite operators of generating functions and performance structure functions thereof. When composition operators are executed, computational costs can be reduced by a big margin by means of collecting like terms. The results of theoretical analysis and numerical simulation show that the generating function approach can be widely used for probability modeling of large complex systems with hierarchical structures due to the unified form, compact expression, computer program realizability and high universality. Because the new method considers twin loads giving rise to component failure dependency, it can provide a theoretical reference and act as a powerful tool for static, dynamic reliability analysis in civil engineering structures and mechanical equipment systems with multi-mode damage coupling.

关键词： structure reliability generating function static strength failure fatigue failure failure dependence

STEP-NC Based High-level Machining Simulations Integrated with CAD/CAPP/CAM

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International Journal of Automation and computing 2012年第5期9卷 506-517页

作者： Yu Zhang 1 Xiao-Lan Bai 1 Xun Xu 2 Yong-Xian Liu 1 1.school of Mechanical Engineering & Automation,northeastern university,shenyang 110004,China 2 school of Engineering,university of Auckland,Auckland 1010,New Zealand school of Mechanical Engineering & Automation Northeastern University Shenyang China school of Engineering University of Auckland Auckland New Zealand

With the development of manufacturing,numerical control(NC) machining simulation has become a modern tool to obtain safe and reliable machining *** some research and commercial software about NC machining simulations is available,most of them is oriented for G&M *** is a low-level data model for computer numerical control(CNC),which has inherent drawbacks such as incomplete data and lack of *** limitations hinder the development of a real simulation ***,standard for the exchange of product data-compliant numerical control(STEP-NC) is a new and high-level data model for *** provides rich information for CNC machine tools,which creates the condition for an informative and real ***,this paper proposes STEP-NC based high-level NC machining simulations solution integrated with computer-aided design/computeraided process planning/computer-aided manufacturing(CAD/CAPP/CAM).It turned out that the research provides a better informed simulation environment and promotes the development of modern manufacturing.

关键词： Standard for the exchange of product data-compliant numerical control(STEP-NC) numerical control(NC) machining machining simulation IDEF0 method ISO 6983

Fuzzy H∞ Filter Design for a Class of Nonlinear Systems with Time Delays via LMI

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自动化学报 2005年第3期 64-71页

作者： LUN Shu-Xian~(1’2) ZHANG Hua-Guang~1 ~1.school of Information Science and Engineering,northeastern university,shenyang 110004)~2(school of Information Science and Engineering,Bohai university,Jinzhou 110004)

This paper develops fuzzy Hfilter for state estimation approach for nonlinear discrete- time systems with multiple time delays and unknown bounded *** design a stable fuzzy Hfilter based on the Takagi-Sugeno (T-S) fuzzy model,which assures asymptotic stability and a prescribed Hindex for the filtering error *** condition for the existence of such a filter is established by solving the linear matrix inequality (LMI) *** LMI problem can be efficiently solved with global convergence using the interior point *** examples are provided to illustrate the design procedure of the proposed method.

关键词： Nonlinear systems H_∞ filter state estimation Takagi-Sugeno fuzzy model time delays linear matrix inequality(LMI)

External synchronization of two dynamical systems with uncertain parameters

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Science China(Technological Sciences) 2010年第3期53卷 731-740页

作者： HAN QingKai 1,SUN XiaoYu 2,YANG XiaoGuang 3 &WEN BangChun 1 1.school of Mechanical Engineering&Automation,northeastern university,shenyang 110004,China 2 school of Electrical Engineering,shenyang university of Technology,shenyang 110023,China 3school of Mechanical Engineering,The university of Birmingham,Birmingham,B15 2TT,UK school of Mechanical Engineering & Automation Northeastern University Shenyang China school of Electrical Engineering Shenyang University of Technology Shenyang China school of Mechanical Engineering The University of Birmingham Birmingham UK

External synchronization is addressed as two or more dynamical systems with synchronous motions,which is also regarded as master-slave *** this paper,two dynamical systems,one employs a hysteretic term to model the friction phenomenon,the other involves a hardening stiffness component with the third order of displacement due to flexible deformation,are controlled to converge to the same *** control strategy is extended from feedback control for all parameters known to adaptive control for linear parameters unknown and all parameters *** slave system can keep synchronous motions with the movements of master via the designed control strategy even all the parameters are not *** stability of synchronization error,the transient process into synchronization and the effects of parameters on the designed controller using different control strategies are *** simulation results unfold the feasibility and effectiveness of this synchronization method.

关键词： controlled synchronization uncertain parameters hysteretic system Duffing system

Influence of Controlled Rolling and Cooling Process on the Mechanical Properties of Low Carbon Cold Forging Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 595-599页

作者： LI Zhuang 1,WU Di 2,ZHENG Hui 1,DONG Xue-xin 2 (1.school of Materials Science and Engineering,shenyang university of Aeronautics and Astronautics,shenyang 110136,Liaoning,China 2.State Key Laboratory of Rolling and Automation,northeastern university,shenyang 110004,Liaoning,China) shenyang Univ Aeronaut & Astronaut Sch Mat Sci & Engn Shenyang 110136 Liaoning Peoples R China northeastern Univ State Key Lab Rolling & Automat Shenyang 110004 Liaoning Peoples R China

In the present paper,controlled rolling and cooling processing was conducted by using a laboratory hot rolling *** influence of different processing parameters on the mechanical properties of low carbon cold forging steel was *** results show that the faster cooling after the deformation (especially in low temperature rolling conditions) leads to the refinement of the ferrite *** specimen exhibits very good mechanical properties owing to the finer ferrite *** pearlite morphologies can also affect the mechanical properties of low carbon cold forging *** mechanical properties increase with decreasing final cooling temperature within the range from 650℃ to 570 ℃ due to the finer interlamellar spacing of pearlite *** mechanical properties of the specimens with fast cooling after the conventional rolling are not only better than those of the specimens with slow cooling after low temperature rolling,but also almost similar to those of the specimens with fast cooling after low temperature *** is suggested that fast cooling after high temperature rolling (the conventional rolling) process would be of important industrial value.

关键词： controlled rolling and cooling process low carbon cold forging steel fast cooling the finer ferrite grains mechanical properties

Adaptive synchronization of neural networks with different attractors

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Progress in Natural Science:Materials International 2007年第6期17卷 687-695页

作者： Zhang Huaguang1, Guan Huanxin1 and Wang Zhanshan1,2(1. school of Information Science and Engineering, northeastern university, shenyang 110004, China 2. school of Information Science and Engineering, shenyang Ligong university, shenyang 110168, China) NE Univ Sch Informat Sci & Engn Shenyang 110004 Peoples R China shenyang Ligong Univ Sch Informat Sci & Engn Shenyang 110168 Peoples R China

This paper aims to present an adaptive control scheme for the synchronization of two classes of uncertain neural networks with different attractors. A new sufficient condition for the global synchronization of two kinds of neural networks with different attractors is derived. The proposed control method is efficient and easy to be implemented. Numerical simulation is used to show the effectiveness of the obtained result.

关键词： neural networks attractor adaptive synchronization linear matrix inequality.

Study of Bake Hardenability and Strengthening Mechanism of Hot Rolled Low Carbon Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 337-341页

作者： LI Wei-juan 1,WANG Guo-dong 2 (1.school of Materials and Metallurgy,university of Science and Technology Liaoning,Anshan 114051,China 2.The State key Laboratory of Rolling and Automation,northeastern university,shenyang 110004,China) Univ Sci & Technol Liaoning Sch Met & Mat Anshan 114051 Peoples R China northeastern Univ State Key Lab Rolling & Automat Shenyang 110004 Peoples R China

The controlled rolling and controlled cooling,bake hardening experiments have been carried out for the test steel,mechanical property test of the sample and microstructure analysis have been made by tensile testing machine,optical microscope,TEM and X-ray *** results show that fine and uniform microstructures can achieve much higher BH and BHT values;With the increase of pre-strain there is a trend of increase first and then decrease in the BH and BHT values;bake hardening mechanism mainly consists of Cottrell atmosphere strengthening,second phase strengthening,dislocation strengthening.

关键词： bake hardening BH value BHT value

MECHANICAL PROPERTIES IN AN INTERCRITICALLY HEAT-TREATED BAINITE-TRANSFORMED 2%Si STEEL

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 725-731页

作者： Z. Li1,2) and D. Wu1)1) State Key Lab of Rolling and Automation, northeastern university, shenyang 110004, China2) Institute of Aeronautical Engineering, shenyang 110034, China Lab. of Rolling Technol. Northeastern Univ. Shenyang 110004 China Inst. of Aeronautical Eng. Shenyang 110034 China

A significant amount of austenite can be retained by rapid cooling following intercritical annealing and holding at the bainite transformation range in steel with comparatively low carbon and silicon contents. Retained austenite is blocky and very fine and moderately stabilized due to C enrichment. The elongation and the strength-ductility balance of the steel can be enhanced considerably due to strain-induced martensite transformation and transformation-induced plasticity (TRIP) of retained austenite.

关键词： mechanical properties intercritical annealing retained austenite bainite transformation steel