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Analysis on cohesive crack opening displacement considering the strain softening effect

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Science China(Physics,Mechanics & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2 & ZHAO Xiqiang3.1. Mechanics Department, shandong University of technology, Zibo 255049, China 2. Civil Engineering Department, Dalian University of technology, Dalian 116024, China 3. Mathematics Department, Ocean University of China, {3. 266071, China Mechanics Department Shandong University of Technology Zibo 255049 China Civil Engineering Department Dalian University of Technology Dalian 116024 China Mathematics Department Ocean University of China Qingdao 266071 China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

Israeli Water Achievements Today and Enlightenment to China

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Chinese Journal of Population,Resources and Environment 2008年第4期6卷 72-77页

作者： Sun Lei1,2, Xu Lanqing3.1. Institute of Environmental Science and Engineering, Ocean University of China, qingdao shandong 266100, China 2. Department of Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, the Hebrew University of Jerusalem, 76100, Israel 3. Logistics Group of Ocean University of China, qingdao shandong 266100, China Institute of Environmental Science and Engineering Ocean University of China Qingdao Shandong 266100 China Department of Soil and Water Sciences Faculty of Agricultural Food and Environmental Quality Sciences the Hebrew University of Jerusalem 76100 Israel Logistics Group of Ocean University of China Qingdao Shandong 266100 China

Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing population. The achievements of water supply in Israel can be summarized as water technologies (like water transportation and purification, desalination, wastewater treatment, effluent reuse, storm water catchment, control systems, rain enhancement and drip irrigation, etc.), water management and legislation as well as water industry. In view of the national concern regarding the quality and quantity of the water, the skills, technologies and know-how that Israel has accumulated in water supply and irrigation can give us enlightenment that is also presented in this paper.

关键词： Israel China water technology water management water industry

Ancient Changjiang channel system in the East China Sea continental shelf during the last glaciation

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Science China Earth Sciences 2005年第11期48卷 1972-1978页

作者： LI Guangxue1,2, LIU Yong1, YANG Zigeng3. YUE Shuhong4, YANG Wenda5 & HAN Xibin1 1. College of Marine Geo-science, Ocean University of China, qingdao 266003. China 2. shandong Key Laboratory of Sea Floor Resource and Exploration Technique, qingdao 266003. China 3. qingdao Institute of Marine Geology, qingdao 266071, China 4. College of Marine Environment, Ocean University of China, qingdao 266003. China 5. First Survey Team of Marine Geology, Shanghai Bureau of Petroleum, Shanghai 201208, China 1. College of Marine Geo-science Ocean University of China 266003 Qingdao China 2. shandong Key Laboratory of Sea Floor Resource and Exploration Technique 266003 Qingdao China 3. qingdao Institute of Marine Geology 266071 Qingdao China 4. College of Marine Environment Ocean University of China 266003 Qingdao China 5. First Survey Team of Marine Geology Shanghai Bureau of Petroleum 201208 Shanghai China

Based on the data of high-resolution seismic profiles, an ancient river channel sys-tem of the last glaciation occurred along the Zhedong and Xihu depression in the southeast of Hupijiao rise. The distribution of the channel fill system shows that the ancient Changjiang River went through the Changjiang depression into the low land plain of the outside continental shelf during the low sea level cycle of the last glaciation. The big channel fill into Okinawa Trough is not found due to the depletion of the river kinetic energy in the low land plain. The river discharge dispersal was of an important role to the dilution of the northern Okinawa Trough sea at that time. Six ancient river channel systems (A―F), which are main distributaries of ancient Changjiang in the East China Sea continental shelf during the last glaciation, may be buried off the modern Changjiang estuary. The distribution of these channels coincides with the zonal elevations in the sea floor.

关键词： last glaciation, continental shelf plain, Changjiang River, ancient channel fill

Dominant point detecting based non-uniform B-spline approximation for grain contour

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Science China(Technological Sciences) 2007年第1期50卷 90-96页

作者： ZHAO XiuYang1, YIN YanSheng1,2 & YANG Bo3.1 shandong Key Laboratory of Engineering Ceramics, shandong University, Jinan 250061, China 2 School of Materials, Ocean University of China, qingdao 266003. China 3.State Key Laboratory of Advanced {3. for Materials Synthesis and Processing, Wuhan University of Science and {3., Wuhan 43.070, China 1. shandong Key Laboratory of Engineering Ceramics Shandong University Jinan 250061 China 2. School of Materials Ocean University of China Qingdao 266003 China 3. State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Science and Technology Wuhan 430070 China

Three-dimension reconstruction from serial sections has been used in the last decade to obtain information concerning three-dimensional microstructural ge-ometry. One of the crucial steps of three-dimension reconstruction is getting compact and fairing grain contours. Based on the achievement of closed raw con-tours of ceramic composite grains by using wavelet and level set, an adaptive method is adopted for the polygonal approximation of the digitized raw contours. Instead of setting a fixed length of support region in advance, the novel method computes the suitable length of support region for each point to find the best es-timated curvature. The dominant points are identified as the points with local maximum estimated curvatures. Periodic closed B-spline approximation is used to find the most compact B-spline grain boundary contours within the given tolerance. A flexible distance selection approach is adopted to obtain the common knot vector of serial contours consisting of less knots that contain enough degrees of freedom to guarantee the existence of a B-spline curve interpolating each contour. Finally, a B-spline surface interpolating the serial contours is generated via B-spline surface skinning.

关键词： composite B-spline dominant points control points grain contour

Analysis on Influence Factors of Real-time Identification of Neural Network in Sheet Intelligent Bending

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稀有金属材料与工程 2011年第S3期40卷 14-18页

作者： Su Chunjian, Zhang Guangheng, Guo Sumin shandong University of Science and technology, qingdao 266510, China shandong Univ Sci & Technol Coll Mech & Elect Engn Qingdao 266510 Peoples R China

The scheme of intelligent control system of cap-bending has been advanced in this paper using the neural network technology, based on the prominent problem that bending springback difficult to control accurately during the forming process of cap-bending. The key technology of real-time identification for material performance parameter and friction coefficient was researched, and the back-propagation neural network of real-time identification for material performance parameters and friction coefficient was established, which can real-time identify the needed material performance parameters through the real-time monitoring variable. Factors that affecting recognition results of neural network model were analyzed, such as influences of the selection of the sample date and the algorithm for identification result. Factors affecting neural network generalization ability were discussed, such as influences of the selection of the sample date and the node number of the hidden layer for generalization ability. The results provide a guarantee for improving the convergence accuracy and the generalization ability of network, and provide a basis for the building of intelligent bending control of network model.

关键词： sheet bending intelligent control real-time identification influence factor

Study on curved surface fitting model using GPS and leveling in local area

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中国有色金属学会会刊：英文版 2005年第S1期15卷 148-152页

作者： GUO Jin-yun~1, CHANG Xiao-tao~2, YUE Qiang~3.(1. Department of Territory Information and Surveying Engineering, Xuzhou Normal University, Xuzhou 221009, China 2. Chinese Academy of Surveying and Mapping, Beijing 10003., China 3. shandong University of Science and technology, qingdao 266510, China) Xuzhou Normal Univ Dept Terr Informat & Surveying Engn Xuzhou 221009 Peoples R China Chinese Acad Surveying & Mapping Beijing 100039 Peoples R China shandong Univ Sci & Technol Qingdao 266510 Peoples R China

The height anomaly surface is fitt and the quasi-geoid can be obtained when the height anomaly is determined with the geometric analytic method. Therefore, some mathematical models to fit height anomaly surface using GPS, leveling and terrain data in a local area, including the polynomial fitting model, the multi-surface function fitting model, the motion surface fitting model and the fitting model of little flexibility deformation of thin board, are given. Then the digital characteristics are analyzed with the curved surface theory. The General curvature and the mean curvature of surface are concluded. The advantage, disadvantage and application of the above models are discussed. The effect of terrain undulation on height anomaly is considered in the surface fitting models. The practical case indicates that these models are of validity and practicability. It is concluded that the above models can give the good fitting results at the centimeter level. But the polynomial fitting model is worse than the other models.

关键词： GPS height anomaly terrain effect curve surface fitting

A new method of ionospheric-free hybrid differential positioning based on a double-antenna CAPS receiver

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Science China(Physics,Mechanics & Astronomy) 2009年第3期52卷 368-375页

作者： GUO JinYun1,2, HAN YanBen1 & CHANG XiaoTao3.1 National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2 College of Geodesy and Geomatics, shandong University of Science and technology, qingdao 266510, China 3.Chinese Academy of Surveying and Mapping, Beijing 10003., China 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China 2. College of Geodesy and Geomatics Shandong University of Science and Technology Qingdao 266510 China 3. Chinese Academy of Surveying and Mapping Beijing 100039 China

Chinese Area Positioning System (CAPS) is a transmitted satellite navigation system moved by the Chinese Academy of Sciences. Three basic modes of navigation and positioning with CAPS are given, and then a comparative analysis is made in this paper. In terms of the principle that the ionospheric delay is at an inverse ratio to the frequency square, a new ionospheric-free positioning method based on a double-antenna CAPS receiver is put forward. Then the hybrid differential observations and the solving equations and algorithms for one epoch and multi epochs are deduced according to the basic principle of the method. The method may remove the global errors in signal emission, propagation, transmission and receiving (e.g., ionospheric delay, hardware delay, and clock error). So it is very convenient for the single-epoch solution and multi-epoch navigation and positioning, and may efficiently improve the precision of real time CAPS navigation. Furthermore, the method can be used not only for the geometric orbit determination of CAPS GEO and IGSO satellites and the navigation and positioning, but also for the estimation of the tropospheric zenith delay, which is useful for the study of water vapor changes in the atmosphere. Polynomials are used in this method to express the tropospheric zenith delay and CAPS satellite orbits within the limited time interval, which reduces the num- ber of unknown parameters and thus speeds the computation.

关键词： Chinese Area Positioning System (CAPS) ionospheric-free linear combination double-antenna receiver hybrid differential positioning method

The Variational Lyapunov Method and Stability for Impulsive Delay Differential Systems

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Journal of Mathematical Research and Exposition 2010年第1期30卷 67-77页

作者： Kai En LIU1,2, Guo Wei YANG3.1. School of Mathematics, qingdao University, shandong 266071, P. R. China 2. Center for Systems and Control, College of Engineering, Peking University, Beijing 100871, P. R. China 3. School of Automation Engineering, qingdao University, shandong 266071, P. R. China School of Mathematics Qingdao University Shandong P.R.China 266071 School of Automation Engineering Qingdao University Shandong P.R.China 266071

By using the variational Lyapunov method and Razumikhin technique, the stability criteria in terms of two measures for impulsive delay differential systems are established. The known results are generalized and improv... 详细信息

关键词： impulsive delay differential system stability variational Lyapunov method Razumikhin technique two measures.

Scattering of SH waves induced by a symmetrical V-shaped canyon: a unified analytical solution

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Earthquake Engineering and Engineering Vibration 2012年第4期11卷 445-460页

作者： Zhang Ning Gao Yufeng Li Dayong Wu Yongxin Zhang Fei Geotechnical Research Institute Hohai University Key Laboratory of Geomechanics and Embankment Engineering(Hohai University) Ministry of Education College of Civil Engineering&Architecture Shandong University of Science and Technology

This paper reports a series solution of wave functions for two-dimensional scattering and diffraction of plane SH waves induced by a symmetrical V-shaped canyon with different shape ratios. A half-space with a symmetrical V-shaped canyon is divided into two sub-regions by using a circular-arc auxiliary boundary. The two sub-regions are represented by global and local cylindrical coordinate systems, respectively. In each coordinate system, the wave field satisfying the Helmholtz equation is represented by the separation of variables method, in terms of the series of both Bessel functions and Hankel functions with unknown complex coefficients. Then, the two wave fields are described in the local coordinate system using the Graf addition theorem. Finally, the unknown coefficients are sought by satisfying the continuity conditions of the auxiliary boundary. To consider the phase characteristics of the wave scattering, a parametric analysis is carried out in the time domain by assuming an incident signal of the Ricker type. Surface and subsurface transient responses demonstrate the characteristics and mechanisms of wave propagating and scattering.

关键词： SH-wave scattering V-shaped canyon topographic effect wave propagation earthquake ground motion wave function expansion method