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Initial densification strain point's determination of honeycomb structure subjected to out-of-plane compression

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Journal of Central South University 2017年第7期24卷 1671-1675页

作者： WANG Zhong-gang ZHOU Wei LIU Jie-fu School of Traffic&Transportation Engineering Key laboratory of Traffic Safety on Track of Ministry of EducationCentral South UniversityChangsha 410075China CRRC Qingdao Sifang Co.Ltd. Qingdao 266111China

Compression ratio is significant for cellular structures on energy absorption. In the present work, theoretical formulas to determine the initial densification strain of honeycomb structure were put forward by means of minimum energy principle. Detailed densification strain points were identified, with full fold model for kinds of specimens. To validate, corresponding numerical simulations were carried out with explicit finite element method. Excellent agreement in terms of initial densification stain point has been observed between the theoretical calculation and numerical simulation. The results show that: (1) a different honeycomb structure has different initial densification strain point, and its geometric configuration of cells plays an evident role on densification; (2) half-wave length of the wrinkle of honeycomb in folding process significantly influences on the densification strain point; (3) the initial densification point is an decreasing power function of the ratio of foil thickness to cell length, with the exponent 2/3. These achievements provide important references for design in cellular energy absorption devices.

关键词： honeycomb densification strain full fold element half-wave length

Measurement of the linear electro-optic coefficient of a minute cBN sample

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Science China(Technological Sciences) 2005年第2期48卷 233-340页

作者： DOU Qingping1, , MA Haitao1, JIA Gang1, CHEN Zhanguo1 2 & ZHANG Tiechen3 1. College of Electronic Science and Engineering, State Key Laboratory on Integrated Optoelectronics, Jilin University, Changchun 130023, China 2. Mudanjiang Normal Institute, Mudanjiang 157012, China 3. State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China College of Electronic Science and Engineering State Key Laboratory on Integrated Optoelectronics Jilin University Changchun China Mudanjiang Normal Institute Mudanjiang China State Key Laboratory of Superhard Materials Jilin University Changchun China

Cubic boron nitride (cBN) is a kind of artificial (synthetic) crystal. Transverse electro-optic modulation in a minute cBN sample was carried out. Basing on the practical form of the crystal, we established the theoretical and experimental method according to the sample. For the first time, the linear electro-optic effect was observed in cBN, and half-wave voltage of the cBN sample was measured successfully. Furthermore, its linear electro-optic coefficient was calculated at 1.17×10?14 m/V.

关键词： cBN crystal, linear electro-optic effect, half-wave voltage, linear electro-optic coefficient.

Mechanical analysis of low β 162.5 MHz taper HWR cavity

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强激光与粒子束 2016年第4期28卷 170-174页

作者：范培亮朱凤钟胡天翔全胜文刘克新北京大学重离子物理研究所北京 100871 中国工程物理研究院流体物理研究所四川绵阳 621900

Peking University is designing a superconducting taper-type half-wave resonator （HWR） withfrequency of 162.5 MHz and β of 0.09 for high current proton beam （about 100 mA） and deuteron beam （about50 mA） acceleration. For this kind of SRF cavity, mechanical analysis is important to predict the frequencyshift caused by the cavity deformation. ANSYS codes are used to analyse the frequency shift caused by heliumbath pressure and Lorentz force, and the tuning range. Simulation results show that this HWR cavity has pressure sensitivity as low as 31.1 Hz/kPa and Lorentz force detuning coefficient of --0.41 Hz/（MV · m ^-1）e. Thetuning range of the cavity is ±4 177 kHz which is wide enough for compensating the possible frequency *** mechanical property of the cavity permits the cavity＇s stable operation.

关键词： half-wave resonator tuning Lorentz force detuning helium pressure detuning

INFLUENCE OF REFLECTION COEFFICIENT ON THE TRAVELING wave MODULATOR PERFORMANCES

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Journal of Electronics(China) 1998年第4期15卷 378-382页

作者： Gou Yaxiong Chen Wen(Shanghai Telecommunication Technology Institute, Shanghai 200120)Li Ying(Shanghai University, Shanghai 201800)

The characteristics of Ti:LiNO3 traveling wave modulator have been analyzed in this paper, taking into account the reflection coefficient of the terminator. The main emphasis of the present work is placed on the descr... 详细信息

关键词： Traveling wave modulator half-wave voltage Impulse response