Dynamic stiffness matrix of an axially loaded slender double-beam element

Li Jun,Hua Hongxing,Li Xiaobin 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

Dynamic stiffness matrix of an axially loaded slenderdouble-beam element

Jun, Li,Hongxing, Hua,Xiaobin, Li Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

Thermal-fluid-structure coupling analysis on plate-type fuel assembly under irradiation. Part-II Mechanical deformation and thermal-hydraulic characteristics

Li, Yuanming,Ren, Quan-yao,Yuan, Pan,Su, Guanghui,Yu, Hongxing,Zheng, Meiyin,Wang, Haoyu,Wu, Yingwei,Ding, Shurong Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.5

The plate-type fuel assembly adopted in nuclear research reactor suffers from complicated effect induced by non-uniform irradiation, which might affect stress conditions, mechanical behaviors and thermal-hydraulic performance of the fuel assembly. This paper is the Part II work of a two-part study devoted to analyzing the complex unique mechanical deformation and thermal-hydraulic characteristics for the typical plate-type fuel assembly under irradiation effect, which is on the basis of developed and verified numerical thermal-fluid-structure coupling methodology under irradiation in Part I of this work. The mechanical deformation, thermal-hydraulic performance and Mises stress have been analyzed for the typical plate-type fuel assembly consisting of support plates under non-uniform irradiation. It was interesting to observe that: the plate-type fuel assembly including the fuel plates and support plates tended to bend towards the location with maximum fission rate; the hot spots in the fuel foil appeared at the location with maximum thickness increment; the maximum Mises stress of fuel foil was located at the adjacent location with the maximum plate thickness increment et al.

Thermal-fluid-structure coupling analysis for plate-type fuel assembly under irradiation. Part-I numerical methodology

Li, Yuanming,Yuan, Pan,Ren, Quan-yao,Su, Guanghui,Yu, Hongxing,Wang, Haoyu,Zheng, Meiyin,Wu, Yingwei,Ding, Shurong Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.5

The plate-type fuel assembly adopted in nuclear research reactor suffers from complicated effect induced by non-uniform irradiation, which might affect its stress conditions, mechanical behavior and thermal-hydraulic performance. A reliable numerical method is of great importance to reveal the complex evolution of mechanical deformation, flow redistribution and temperature field for the plate-type fuel assembly under non-uniform irradiation. This paper is the first part of a two-part study developing the numerical methodology for the thermal-fluid-structure coupling behaviors of plate-type fuel assembly under irradiation. In this paper, the thermal-fluid-structure coupling methodology has been developed for plate-type fuel assembly under non-uniform irradiation condition by exchanging thermal-hydraulic and mechanical deformation parameters between Finite Element Model (FEM) software and Computational Fluid Dynamic (CFD) software with Mesh-based parallel Code Coupling Interface (MpCCI), which has been validated with experimental results. Based on the established methodology, the effects of non-uniform irradiation and fluid were discussed, which demonstrated that the maximum mechanical deformation with irradiation was dozens of times larger than that without irradiation and the hydraulic load on fuel plates due to differential pressure played a dominant role in the mechanical deformation.

Research on Privacy Protection Approach for Cloud Computing En-vironments

Xiaohui Li,Hongxing Liang,Dan Jia 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.3

Cloud computing is a convenient and cost efficient way that refers to the running of software over a network, as on a local computer. But, what is cheap and easy, isn’t always safe. Stor-ing important data on cloud means that you give up a certain control of privacy. Privacy pro-tection is a very important issue in cloud computing. In this paper,we focus on the need of cloud users managed services and propose an approach for data protection based trust mech-anism, which using adaptive mapping resources based on trust to ensure the user data protec-tion initiative, and data security. The analysis shows that the cloud user can independently con-trols the content and manner of services by using the approach, which can achieve the free de-ployment of resources and the balance of user data protection and service provided.

OSI-027 alleviates rapamycin insensitivity by modulation of mTORC2/AKT/TGF-β1 and mTORC1/4E-BP1 signaling in hyperoxia-induced lung injury infant rats

Long Li,Liang Mulin,Yanling Liu,Wang Pan,Dang Hongxing 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.3

Background The mechanism of long time and high-concentration oxygen treatment leading to acute lung injury (ALI) or developmental lung disease in infants is currently unclear. Here we found that compared with the effect of rapamycin, pan-mTOR1/2 inhibitor OSI-027, alleviates hyperoxia-induced lung injury (HILI) by modulation of mTORC2/AKT/TGF-β1 and mTORC1/4E-BP1 signaling in infant rats. Objective Infant rats were treated with continuous inhalation of 90% medical oxygen. Normal saline, rapamycin, or OSI-027 was intraperitoneally injected, and the status of lung injury was tested on days 3, 7, and 14. The activation of mTOR/AKT/TGFβ1 and mTORC1/4E-BP1 signaling was confirmed by immunohistochemistry and Western blot analysis in normal and hyperoxia-treated live precision-cut lung tissues. The inhibitory effect of OSI-027 extended to the active state of other proteins implicated in mTOR1/2 signaling was demonstrated in hyperoxia-induced injured lung tissues. Results Our data demonstrate that hyperoxia-induced serious lung inflammation and fibrosis. OSI-027 significantly attenuated the pathological process of HILI, inhibit the phosphorylation of the primary downstream targets of mTORC1/C2, and reduce the activation of TGF-β1 signaling. Conclusions The results suggest that mTORC2/AKT/TGF-β1 and the rapamycin-insensitive mTORC1/4E-BP1 (Thr37/46) signaling has an important effect during HILI with a potential meaning for the progress of novel anti-hyperoxia-injury strategies. Background The mechanism of long time and high-concentration oxygen treatment leading to acute lung injury (ALI) or developmental lung disease in infants is currently unclear. Here we found that compared with the effect of rapamycin, pan-mTOR1/2 inhibitor OSI-027, alleviates hyperoxia-induced lung injury (HILI) by modulation of mTORC2/AKT/TGF-β1 and mTORC1/4E-BP1 signaling in infant rats. Objective Infant rats were treated with continuous inhalation of 90% medical oxygen. Normal saline, rapamycin, or OSI-027 was intraperitoneally injected, and the status of lung injury was tested on days 3, 7, and 14. The activation of mTOR/AKT/TGFβ1 and mTORC1/4E-BP1 signaling was confirmed by immunohistochemistry and Western blot analysis in normal and hyperoxia-treated live precision-cut lung tissues. The inhibitory effect of OSI-027 extended to the active state of other proteins implicated in mTOR1/2 signaling was demonstrated in hyperoxia-induced injured lung tissues. Results Our data demonstrate that hyperoxia-induced serious lung inflammation and fibrosis. OSI-027 significantly attenuated the pathological process of HILI, inhibit the phosphorylation of the primary downstream targets of mTORC1/C2, and reduce the activation of TGF-β1 signaling. Conclusions The results suggest that mTORC2/AKT/TGF-β1 and the rapamycin-insensitive mTORC1/4E-BP1 (Thr37/46) signaling has an important effect during HILI with a potential meaning for the progress of novel anti-hyperoxia-injury strategies.

Trust Based Service Selection in Cloud Computing Environment

Xiaohui Li,Hongxing Liang,Xing Zhang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.11

In order to meet cloud user demand for managed service, we propose a scheme based on trust for cloud service selection. The scheme includes the service chosen and services delivered two parts, which can choose the cloud service through its trust value, to meet the safety requirements premise, and make trust decisions to achieve service controllability. First it make choice of the service in accordance with service attributes weight using AHP, then complete user data delivery rely on trust, which allowing users to combine with their own situation and trust in cloud services dynamically adjusting the cloud user data release granularity to reach the controllability of the service .Instance results show that the scheme is effective and can guarantee service selection under safe and controlled conditions.

Dynamic modeling and analysis of axial vibration of a coupled propeller and shaft system

Chenyang Li,Xiuchang Huang,Hongxing Hua 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.7

The dynamic and acoustic characteristics of a coupled propeller and shaft system which is modeled by the transfer matrix method are studied. The elasticity of the propeller is taken into consideration by employing the equivalent reduced modeling method. Thus the influence of the elastic propeller on the vibro-acoustic responses of the coupled system is investigated. To reduce the axial vibration of the coupled propeller-shaft system, the influence and location of the vibration isolator on the structural and acoustic responses is presented. Simulation results demonstrate that utilizing the relationship between the natural frequency of the propeller and the resonance frequency range of the shaft can control the vibration of the coupled system without other vibration control method. Utilizing a vibration isolator is another effective way to control vibration. The optimal position for the isolator installed between the shaft and the thrust bearing is investigated.

Responses of GS-NS0 Myeloma Cells to Osmolality: Cell Growth, Intracellular Mass Metabolism, Energy Metabolism, and Antibody Production

Liang Zhao,Li Fan,Jiaqi Wang,Hongxing Niu,Wen-Song Tan 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.5

The influence of osmolality on growth, metabolism, and antibody production of mammalian cells has been widely reported in the past. However, more information about the responses of GS-NS0 Myeloma cells to osmolality, especially regarding the intracellular mass and energy metabolism, has not been available in detail. Fed-batch cultures started at different osmolalities in the range of 280~370 mOsm/kg were designed to investigate the effects. As the osmolality and cell status changed during the process, cell performance was evaluated in the comparable periods with similar growth rates, nutrition concentrations, and relatively consistent environments. Metabolic flux analysis indicated most of extra consumed glucose at higher osmolalities flowed into lactate formation pathway. The proportion of glucose flux flowed into glycolysis pathway remained approximately 90% and the need of glucose for biomass synthesis was constantly. Also, more than 88% of the glutamine was used in biomass synthesis and the absolute flux remained constant. The specific consumption rate of glutamine declined significantly when cells were cultured in hypo-osmolality (276 mOsm/kg) and a portion of glutamine was synthesized from glutamate. Furthermore, cells were in the state of high energy production at osmolality of 276 mOsm/kg. More glucose flowed into TCA circle with the high efficiency of energy production to meet the demand. Thus, the IVC, the specific antibody production rate, and maximal antibody concentration in fed-batch culture started at 280 mOsm/kg decreased by 35, 36, and 48% compared to those in the culture started at 330 mOsm/kg The influence of osmolality on growth, metabolism, and antibody production of mammalian cells has been widely reported in the past. However, more information about the responses of GS-NS0 Myeloma cells to osmolality, especially regarding the intracellular mass and energy metabolism, has not been available in detail. Fed-batch cultures started at different osmolalities in the range of 280~370 mOsm/kg were designed to investigate the effects. As the osmolality and cell status changed during the process, cell performance was evaluated in the comparable periods with similar growth rates, nutrition concentrations, and relatively consistent environments. Metabolic flux analysis indicated most of extra consumed glucose at higher osmolalities flowed into lactate formation pathway. The proportion of glucose flux flowed into glycolysis pathway remained approximately 90% and the need of glucose for biomass synthesis was constantly. Also, more than 88% of the glutamine was used in biomass synthesis and the absolute flux remained constant. The specific consumption rate of glutamine declined significantly when cells were cultured in hypo-osmolality (276 mOsm/kg) and a portion of glutamine was synthesized from glutamate. Furthermore, cells were in the state of high energy production at osmolality of 276 mOsm/kg. More glucose flowed into TCA circle with the high efficiency of energy production to meet the demand. Thus, the IVC, the specific antibody production rate, and maximal antibody concentration in fed-batch culture started at 280 mOsm/kg decreased by 35, 36, and 48% compared to those in the culture started at 330 mOsm/kg

Second-Order Sliding Mode Control with Backstepping for Aeroelastic Systems Based on Finite-Time Technique

Zhankui Song,Hongxing Li 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.2

In this paper, a backstepping second-order sliding mode control scheme (BSOSMC) is proposed for suppressing both flutter and limit cycle oscillation in the aeroelastic system. The proposed control scheme combining the sliding mode control and backstepping technique, which obtain the properties of fast response and improve the control accuracy. To obtain a better disturbance rejection property, we employ compensated control term. The compensated control term provides the complete compensation of the uncertainty and disturbance, and it relax the requirement of the bound of uncer-tainty and disturbance. The convergence and stability of the proposed control scheme are proved by using Lyapunov’s method. Finally, the simulation results demonstrate the effectiveness of the proposed control scheme.