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Control of Titanium Alloy Thin Plate’s Welding Distortion by Trailing Peening

International Symposium on New Olympics New Shell and Spatial Structures

作者： Ying SUN Yue WU Shen-Zhao SHEN Ph.D Candidate School of Civil Engineering harbin institute of Technology harbin 150090 China Associate Professor School of Civil Engineering harbin institute oftechnology harbin 150090 China Professor School of Civil Engineering harbin institute of Technology harbin 150090 China

＜正＞This paper presents a study on the wind pressure field on large-span roofs, taking into account its non-Gaussian nature. Wind tunnel experiments for several shapes of large-span roofs were carried out in the boundary layer wind tunnel at Tongji University. Analysis presented in this paper is mainly base on the experimental data of large-span flat roofs and saddle-shaped roofs.

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Control of Titanium Alloy Thin Plate’s Welding Distortion b...

Research on the sound absorption performance of metal rubber material

The Fourth International Conference on Physical and Numerical Simulation of Materials (ICPNS’2004)

作者： Xuesong LIU Hongyuan FANG Shude JI and Zhibo DONGState Key laboratory of Advanced Welding Production Technology harbin institute oftechnology

＜正＞The technology of trailing peening is a kind of promisingly bran-new technology which can be used to control welding stress and distortion of Titanium alloy thin plate. Control of TC4 Titanium alloy thin plate’s welding stress and distortion under the condition of conventional welding and trailing peening is performed respectively. The results show that the technology of trailing peening effectively reduces deflection and transverse shrinkage of thin plate weldment. The maximum deflection is decreased from 15mm under the condition of conventional welding to 5mm, while the weld transverse shrinkage is decreased from 0.5mm to about 0.1mm.

关键词： Control of residual stress and distortion Trailing peening TC4 Titanium alloy

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Chinese Journal of Acoustics 2009年第2期28卷 154-162页

作者： XIA Yuhong JIANG Hongyuan WU Guoqi E.A. Izzheurov School of mechatronics engineering Harbin Institute of Technology Harbin 150001 Samara State Aerospace University Samara of Russia 443086

The sound absorption performance of Metal Rubber material was studied theoretically and experimentally. The acoustic impedance rate and the sound absorption coefficient were derived based on the acoustic parameters of metal rubber material. The relation of structure constant, compressibility modulus and structural parameters was investigated experimentally. The results showed that the specimen of metal rubber with the same mean porosity diameter had the same structure constant. For the same structural parameters, the compressibility modulus of metal rubber material was approximately constant in certain frequency range. The calculated acoustic parameters are in good agreement with the experimental results, demonstrating the effectiveness of theoretical models.

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基于十字形的改进新型频率选择表面

微波学报 2010年第S2期26卷 29-32页

作者：张桐王晓鲁李宛露高前超杨国辉哈尔滨工业大学电子与信息工程学院哈尔滨150001

通过对传统的十字单元进行改进,设计了两种新型单元的频率选择表面(FSS)。利用谱域分析法,从理论上分析了传统十字单元和新型单元FSS,研究了TE波入射时角度变化和大角度入射下极化方式变化对中心频率的影响。仿真结果表明:在TE波从0°... 详细信息

通过对传统的十字单元进行改进,设计了两种新型单元的频率选择表面(FSS)。利用谱域分析法,从理论上分析了传统十字单元和新型单元FSS,研究了TE波入射时角度变化和大角度入射下极化方式变化对中心频率的影响。仿真结果表明:在TE波从0°～60°以不同角度入射时,传统十字单元的中心频率漂移为420 MHz,两种新型单元中心频率的漂移量分别为180MHz和210MHz,减少了1/2以上;在45°不同极化方式的波入射时,传统十字单元中心频率的漂移量为990MHz,两种新型单元的漂移量为150MHz和120MHz,减少了2/3以上。与传统十字单元相比,两种新型FSS单元均能实现TE波入射时的角度稳定性和大角度入射时的良好的极化稳定性,为FSS在天线雷达领域中的应用提供了基础。

关键词：频率选择表面极化稳定性角度稳定性

Autonomous control of multi-fingered hand

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Progress in Natural Science:Materials International 2006年第5期16卷 531-537页

作者： JIANG Li and LIU Hong (Robotics Research institute, harbin institute of Technology, harbin 150001, China) Robotics Research institute Harbin Institute of Technology Harbin 150001 China

This paper describes a novel autonomous control strategy of multi- fingered hand based on a modular control system of dexterous manipulation. A simple proportional-integral-derivative(PID) position control with friction compensation, which requires few friction parameters, is used to realize accurate and smooth trajectory tracking in pregrasp phase. In grasp and manipulation phases, an event-driven switcher is adopted to determine the switching between unconstrained position control and constrained torque control, and an improved explicit integral force control strategy is implemented to realize simultaneously stable contact transition and accurate force tracking. Experimental results have verified the effectiveness of the proposed autonomous control strategy of multi-fingered hand.

关键词： multi-fingered hand autonomous control position control impact control.

CORRELATION BETWEEN MICROSTRUCTURE AND STRESS CORROSION CRACKING SUSCEPTIBILITY OF 2091 ALLOY

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Acta Metallurgica Sinica(English Letters) 1992年第12期5卷 483-488页

作者： LJ Benshun harbin institute of Technology,harbin,China CHEN Xiangping lianghan Petroleum institute,Wuhan,China harbin Inst of Technology Harbin China

The stress corrosion cracking(SCC) susceptibility of an Al-Li-Cu-Mg-Zr alloy(2091), heat-treated under different regime,has been investigated hy means of tensile tests at slow strain *** microstructure has been examined with *** deformation characteristic has also been *** stress corrosion resistance of the alloy was revealed to be mainly affected by the covering rate of T_2-phase over grain boundaries and by the average distance between T_2-phase particles. SCC resistance can be obviously improved by predeforming the alloy at room temper- ature to reduce the precipitation of T_2-phase along grain boundaries.

关键词： AI-Li alloy stress corrosion microstructure pre-deformation

SIMULATION STUDY OF GENERALIZED MINIMUM VARIANCE CONTROL FOR AN EXTRACTION TURBINE

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Chinese Journal of Mechanical Engineering 2003年第4期16卷 424-427,444页

作者： Shi XiaopingSimulation Center,harbin institute of Technology,harbin 150001, China Simulation Center Harbin Institute of Technology Harbin 150001 China

In an extraction turbine, pressure of the extracted steam and rotate speed of the rotor are two important controlled quantities. The traditional linear state feedback control method is not perfect enough to control the two quantities accurately because of existence of nonlinearity and coupling. A generalized minimum variance control method is studied for an extraction turbine. Firstly, a nonlinear mathematical model of the control system about the two quantities is transformed into a linear system with two white noises. Secondly, a generalized minimum variance control law is applied to the system. A comparative simulation is done. The simulation results indicate that precision and dynamic quality of the regulating system under the new control law are both better than those under the state feedback control law.

关键词： Extraction turbine Rotate speed Generalized minimum variance control Simulation

INTERGRANULAR EMBRITTLEMENT IN PLASMA CARBURIZED LAYER

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Acta Metallurgica Sinica(English Letters) 1992年第2期5卷 141-144页

作者： XIA Lifang MA Xinxin harbin institute of Technology,harbin,China harbin Inst of Technology Harbin China

This paper deals with the cause of intergranular fracture occurred in the retained austenitic region in plasma carburized *** results show that the presence of retained austenite, which has a good effect on the impact toughness,has no relation to this ***- sis by Auger electron spectroscopy shows that the impurities S and P segregate at the grain boundaries is the main reason of the intergranular embrittlement in carburized layer. However,the segregation of P and S can be removed by reheating and quenching treatment.

关键词： plasma carburizing carburizing embrittlement impurity segregation

IN-SITU OBSERVATION OF THERMAL FATIGUE CRACK GROWTH IN STEEL 3Cr2W8V

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Acta Metallurgica Sinica(English Letters) 1993年第3期6卷 191-192页

作者： LIU Jianhong HE Shiyu YAO Mei harbin institute of Technology,harbin,China lecturer,Depatment of Metallic Materials,harbin institute of Technology,harbin 150006,China harbin Inst of Technology Harbin China

The growing process of thermal fatigue cracking,in steel 3Cr2WSV was observed under desk SEM fitted with sell-made minisized device for thermal faligue *** the growing of thermal fatigue crack,the main crack tip reveals to blunt firstly,and some holes and uncontinuous microcraeks occur in front of *** growth is developed by bridging of main crack together with holes and microcracks.

关键词： steel 3Cr2W8V thermal fatigue crack growth in-situ observation