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Research on the iterative method for model updating based on the frequency response function

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Acta Mechanica Sinica 2012年第2期28卷 450-457页

作者： Wei-Ming Li jia-zhen hong Department of Engineering Mechanics Shanghai Jiaotong University200240 ShanghaiChina

Model reduction technique is usually employed in model updating process. In this paper, a new model updat- ing method named as cross-model cross-frequency response function （CMCF） method is proposed and a new iterative method associating the model updating method with the mo- del reduction technique is investigated. The new model up- dating method utilizes the frequency response function to avoid the modal analysis process and it does not need to pair or scale the measured and the analytical frequency re- sponse function, which could greatly increase the number of the equations and the updating parameters. Based on the traditional iterative method, a correction term related to the errors resulting from the replacement of the reduction ma- trix of the experimental model with that of the finite element model is added in the new iterative method. Comparisons be- tween the traditional iterative method and the proposed itera- tive method are shown by model updating examples of solar panels, and both of these two iterative methods combine the CMCF method and the succession-level approximate reduc- tion technique. Results show the effectiveness of the CMCF method and the proposed iterative method .

关键词： Model updating Model reduction Frequency response function Iteration

An efficient formulation based on the Lagrangian method for contact–impact analysis of flexible multi-body system

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Acta Mechanica Sinica 2016年第2期32卷 326-334页

作者： Peng Chen Jin-Yang Liu jia-zhen hong Department of Engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiaotong University

In this paper,an efficien formulation based on the Lagrangian method is presented to investigate the contact–impact problems of f exible multi-body ***,the penalty method and the Hertz contact law are the most commonly used methods in engineering ***,these methods are highly dependent on various non-physical parameters,which have great effects on the simulation ***,a tremendous number of degrees of freedom in the contact–impact problems will influenc thenumericalefficien *** of these two problems,a formulation combining the component mode synthesis method and the Lagrangian method is presented to investigate the contact–impact problems in fl xible multi-body system ***,the finit element meshing laws of the contact bodies will be studied preliminarily.A numerical example with experimental verificatio will certify the reliability of the presented formulationincontact–***,aseries of numerical investigations explain how great the influenc of the finit element meshing has on the simulation *** the limitations of the element size in different regions are summarized to satisfy both the accuracy and efficien y.

关键词： Multi-body dynamics Contact–impact analysis Lagrangian method Component mode synthesis

Contact-impact formulation for multi-body systems using component mode synthesis

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Acta Mechanica Sinica 2013年第3期29卷 437-442页

作者： Peng Chen Jin-Yang Liu jia-zhen hong Department of Engineering Mechanics School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University

The efficiency and accuracy are two most concerned issues in the modeling and simulation of multi-body systems involving contact and impact. This paper proposed a formulation based on the component mode synthesis method for planar contact problems of flexible multi-body systems. A flexible body is divided into two parts： a contact zone and an un-contact zone. For the un-contact zone, by using the fixed-interface substructure method as reference, a few low-order modal coordinates are used to replace the nodal coordinates of the nodes, and meanwhile, the nodal coordinates of the local impact region are kept unchanged, therefore the total degrees of freedom （DOFs） are greatly cut down and the computational cost of the simulation is significantly reduced. By using additional constraint method, the impact constraint equations and kinematic constraint equations are derived, and the Lagrange equations of the first kind of flexible multi-body system are obtained. The impact of an elastic beam with a fixed half disk is simulated to verify the efficiency and accuracy of this method.

关键词： Contact-impact analysis · Flexible multi-body system · Component mode synthesis

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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Optoelectronics Letters 2008年第4期4卷 276-279页

作者： DONG Wu-qin jia zhen-hong College of Information Science and Engineering Xinjiang university Urumqi 830046 China

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.

关键词：应力测量光纤传感器布里渊散射增益系数理论分析

Numerical and experimental studies on impact dynamics of a planar flexible multibody system

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Acta Mechanica Sinica 2010年第4期26卷 635-642页

作者： Fu-Xiang Dong jia-zhen hong Kun Zhu zheng-Yue Yu Department of Engineering Mechanics Shanghai Jiaotong University 200240 Shanghai China

In this paper a computational methodology on impact dynamics of the flexible multibody system is presented. First, the floating frame of reference approach and nodal coordinates on the basis of finite element formulation are used to describe the kinematics of planar deformable bodies. According to the kinematic description of contact conditions, the contact constraint equations of planar flexible bodies are derived. Based on the varying topology technique the impact dynamic equations for a planar multibody system are established. Then the initial conditions of the equations in each contact stage are determined according to the discontinuity theory in continuum mechanics. The experiments between the aluminum rods are performed to check the correctness of the proposed method. Through the comparison between the numerical and experimental results the proposed method is validated. Experimental results also show that the impulse momentum method cannot accurately predict the complex impact dynamic phenomena and the continuous model may lead to a serious error when used to simulate the impact problems with significant wave propagation effects.

关键词： Flexible multibody system Impact dynamics Appending constraint method (ACM) Impact experiments

A label-free single photonic quantum well biosensor based on porous silicon for DNA detection

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Optoelectronics Letters 2013年第3期9卷 225-228页

作者： LIU Rong-xia CHEN Liang-lJang ZHANG hong-yan jia zhen-hong School of Physical Science and Technology Xinjiang University Urumqi 830046 China Key Laboratory of Xinjiang Biological Resources and Gene Engineering College of Life Sciences and TechnologyXinjiang University Urumqi 830046 China College of Information Science and Engineering Xinjiang University Urumqi 830046 China

The single photonic quantum well （PQW） structures are successfully fabricated on ptype silicon wafer by electro chemical etching process, and are used for DNA detection firstly. The red shift of resonance peak is caused by the changing refractive index of PSi layer, which results from coupling of organic molecules into pores. When the porous silicon （PSi） based single PQW biosensors are immersed in complementary deoxyribonucleic acid （DNA） with differ ent concentrations ranging from 0.625 pM to 10,000 pM, a good linear relationship is observed between the red shift of resonance peak and the complementary DNA concentration. Experimental results show that the detection sensitivity of PSibased single PQW biosensors is 3.04 nm/M with a detection limit of 32 nM for 16base pair DNA oligonu cleotides.

关键词： DNA检测生物传感器量子阱结构多孔硅单光子无标记 DNA浓度脱氧核糖核酸

Partition method for impact dynamics of flexible multibody systems based on contact constraint

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Applied Mathematics and Mechanics(English Edition) 2013年第11期34卷 1393-1404页

作者：段玥晨章定国洪嘉振 School of Mechanical Engineering Zhengzhou University School of Science Nanjing University of Science and Technology Department of Engineering Mechanics Shanghai Jiao Tong University

The impact dynamics of a flexible multibody system is investigated. By using a partition method, the system is divided into two parts, the local impact region and the region away from the impact. The two parts are connected by specific boundary conditions, and the system after partition is equivalent to the original system. According to the rigid-flexible coupling dynamic theory of multibody system, system＇s rigid-flexible coupling dynamic equations without impact are derived. A local impulse method for establishing the initial impact conditions is proposed. It satisfies the compatibility con- ditions for contact constraints and the actual physical situation of the impact process of flexible bodies. Based on the contact constraint method, system＇s impact dynamic equa- tions are derived in a differential-algebraic form. The contact/separation criterion and the algorithm are given. An impact dynamic simulation is given. The results show that system＇s dynamic behaviors including the energy, the deformations, the displacements, and the impact force during the impact process change dramatically. The impact makes great effects on the global dynamics of the system during and after impact.

关键词： flexible multibody system impact dynamics partition method impulse-momentum method contact constraint

Research on immunosensor based on porous silicon

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Optoelectronics Letters 2008年第5期4卷 328-330页

作者： XUE Tao LV Xiao-yi jia zhen-hong HOU Shi-bin ZHANG Fu-chun School of physies Xinjiang University Urumgi 830046 China School of Electronic and Information Engineer Xi ＇an Jiaotong University Xi ＇an 710049 China School of Information Science ＆ Engineering Xinjiang University Urumqi 830046 China Key Laboratory of Biological Resources and Gene Engineering of Xinjiang College of Life Sciences and Technology Xinjiang University Urumgi 830046China.

Porous silicon is functionalized using thermal oxidation and silanization. The HYSA antibodies are immobilized to the porous surface in this paper. The changes in the reflection spectrum and photoluminescence spectrum are investigated when BSA are attached to the PS surface. The result shows that the luminescence peak of PS disappears. After the antigen-antibody reaction,the higher light emission is observed and the reflection spectrum also red shifts. Therefore,this research lays a foundation for the development of sensitive label-free optical immunosensor.

关键词：敏感器件硅硅烷化氧化 HYSA抗体

Self-diffractionin Porous Silicon/PMMA-DR1 Composite Fil ms

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Semiconductor Photonics and Technology 2006年第1期12卷 18-20,42页

作者： jia zhen-hong College of Information Science and Engineering Xinjiang University Urumchi 830046 CHN

Two-layer structure consisting of PS/PMMA-DR1 composite film planar waveguide layer on porous silicon cladding layer was fabricated in our experiment. The induced grating based on the third nonlinear optical properties was formed by interaction of two Nd∶YAG laser beams at 1064nm in the porous silicon/PMMA-DR1 waveguide. The diffraction efficiency of the first order diffracted light is measured to be about 0.2% of the total output.

关键词： Porous Silicon PMMA-DR1 Composite film Self-diffraction Dynamic grating