scholarly journals Single Reflect-Mirror Laser Communication Tracking-Pointing System Load Technology for Micronanosatellite

2022 ◽  
Vol 2022 ◽  
pp. 1-11
Author(s):  
Tie Chi ◽  
Lizhong Zhang ◽  
Lixin Meng
Keyword(s):  
System Design ◽  
Frame Structure ◽  
Frame Structures ◽  
Laser Communication ◽  
Vibration Test ◽  
Test Experiment ◽  
Technical Requirements ◽  
Single Lens ◽  
Pointing Accuracy ◽  
Structural Parts

In order to realize low-orbit microsatellite laser communication, L- and U-frame structures are designed, respectively, for the payload of single-lens reflex (SLR) laser communication tracking and pointing system. According to the characteristics of each load structure, the detailed system design is carried out, and the modal analysis is carried out on the key structural parts of the L- and U-frames to ensure the reliability of each load structure. The pointing accuracy of the two load structures is also calculated and analyzed. Finally, the conclusion is that both of the two load structures can meet the technical and accuracy requirements of low-orbit communication, but obviously, the U-frame structure has higher accuracy, greater pitching angle, and better reliability; eventually, the U-frame structure is adopted in this design. Then, we have completed the manufacture and assembly of the principle prototype and carried out a vibration test experiment on the principle prototype. The results show that the U-type loading structure SLR laser communication tracking and pointing system achieves the expected design purpose and can meet the technical requirements of the low-orbit microsatellite laser communication.

Nonlinear Analysis of a RC Frame Structure with Semi-Interlayers Damaged during Wenchuan Earthquake

2010 ◽  
Vol 156-157 ◽  
pp. 467-472
Author(s):  
Peng Tao Yu ◽  
Jing Jiang Sun
Keyword(s):  
Nonlinear Analysis ◽  
Wenchuan Earthquake ◽  
Time History ◽  
Large Earthquake ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Frame Structures ◽  
Rc Frame ◽  
Rc Frame Structures ◽  
Nonlinear Time History

Under the excitation of large earthquake, structures enter into high nonlinear stage. Currently, Opensees, Perform-3d and Canny are used as the most popular nonlinear analysis procedures. The fiber model will be introduced firstly and the nonlinear analysis models in Canny are explained in detail. Then Canny2007 is used to conduct nonlinear time history analysis on a heavily damaged frame structure with interlayer in Dujiangyan during Wenchuan Earthquake. Analysis shows that the maximum inter-story drift appears between the interlayer and its upper layer, and the heavy damage agrees well with the results of damage investigation. By comparing the damage extent of frame structures with or without interlayer, it reveals that the seismic performance of RC frame structures without interlayer is obviously better than that of ones with interlayer.

Laser Communication System Design

1988 ◽  
Author(s):  
W. L. Casey ◽  
G. R. Doughty ◽  
J. G. Houston, ◽  
R. K. Marston ◽  
L. J. O'Pella ◽  
...  
Keyword(s):  
System Design ◽  
Communication System ◽  
Laser Communication ◽  
Communication System Design

Analysis of the Seismic Performance of RC Frame Structures with Different Types of Bracings

2012 ◽  
Vol 166-169 ◽  
pp. 2209-2215
Author(s):  
Zhi Xin Wang ◽  
Hai Tao Fan ◽  
Huang Juan Zhao
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Steel Tube ◽  
Frame Structure ◽  
Frame Structures ◽  
Finite Element Models ◽  
Base Shear ◽  
Concrete Filled Steel Tube ◽  
Different Types ◽  
Rc Frame Structures

Finite element models of frames with steel-bracings and with concrete filled steel tube struts are built in ETABS. Seismic performance of these models is analyzed with base-shear method, superposition of modal responses method and time history method respectively. The results show that the steel-bracings or concrete filled steel tube struts are efficient to increase the story-stiffness, and the top displacement of the frame structure decreases significantly.

Strain rate dependent formulation of the latent heat evolution of superelastic shape memory alloy wires incorporated in multistory frame structures

2020 ◽  
pp. 1045389X2097547
Author(s):  
Andreas Kaup ◽  
Hao Ding ◽  
Jinting Wang ◽  
Okyay Altay
Keyword(s):  
Shape Memory Alloy ◽  
Strain Rate ◽  
Shape Memory ◽  
Latent Heat ◽  
Heat Evolution ◽  
Shaking Table ◽  
Frame Structure ◽  
Frame Structures ◽  
Rate Dependent ◽  
Multistory Frame

Due to their unique hysteretic energy dissipation capacity, shape memory alloy (SMA) wires are particularly interesting for the development of new-type of intelligent vibration control systems for structures. However, in structural control, most of the vibrations occur in high strain rate regimes, which interfere the release of self-generated heat and thus influence the hysteretic dissipation. This paper proposes a strain rate dependent formulation of the latent heat evolution and aims to improve the accuracy of existing macroscopic modeling approaches developed for SMA wires particularly for the dynamic load cases. The proposed formulation is determined phenomenologically and implemented in a continuum thermomechanical framework based constitutive SMA wire model without impairing the simplicity and robustness of the solution process. The proposed formulation is validated by cyclic tensile tests conducted on SMA wires. Results show that the calculations using the formulation can predict the wire response more accurately than the strain rate independent formulation. For the simulation of multistory frame structures incorporating multiple SMA wires, the governing equations are driven. Shaking table tests are conducted on a 3-story frame structure under harmonic and seismic excitation. The responses of the structure are successfully replicated using the strain rate dependent latent heat formulation.

scholarly journals Design of Lidar System Based on Marine Oil Spill Monitoring

2020 ◽  
Vol 165 ◽  
pp. 03052
Author(s):  
Li Jing ◽  
Che Ying ◽  
Luan Shuang ◽  
Wang Zhaoxin ◽  
Yang Kun
Keyword(s):  
System Design ◽  
Oil Spill ◽  
Oil Pollution ◽  
Structure Design ◽  
Laser Radar ◽  
Light Sources ◽  
Lidar System ◽  
Marine Aquaculture ◽  
Technical Requirements ◽  
Natural Ecology

The occurrence of offshore oil spill will cause great harm to Marine natural ecology and Marine living resources, and seriously affect Marine aquaculture, fishery, tourism and other Marine industries. In the field of monitoring oil spill accident, traditional passive remote sensing measurement is still relying on, and the monitoring of oil spill accident occurring at night is not very good. According to the condition of the surface of the oil spill at night monitoring requirements, design and development of laser radar for monitoring the sea are permeated with oil pollution. This article mainly from the super continuous spectrum of light sources and monochrome laser radar detector selection, spectrometer wavelength calibration, the structure of the optical system design, radar receiving system image quality evaluation, the mechanical structure design and mechanics analysis and prototype design aspects, introduces the first system design of laser radar in detail. The design indexes of lidar system for monitoring oil spill pollution meet the technical requirements.

Development of a New Nonbuckling Segmented Brace

2015 ◽  
Vol 15 (08) ◽  
pp. 1540012 ◽  
Author(s):  
H. Hao
Keyword(s):  
Compressive Force ◽  
Seismic Loading ◽  
Experimental Tests ◽  
Frame Structure ◽  
Structural Deformation ◽  
Frame Structures ◽  
Seismic Responses ◽  
Loading Effects ◽  
Cyclic Loading Tests ◽  
Steel Frame Structure

This paper introduces a new design of segmented nonbuckling brace member for use in frame structures to resist earthquake loading. The proposed segmented brace member consists of one or more segments connected by either tension-only or compressive force controlled joints. Because it cannot resist or can only resist a limited amount of compressive force, it is effective only under tension, but buckling would not be a failure mechanism of the brace. Its capability of mitigating seismic responses remains effective throughout the entire ground excitation duration. The other advantages of this new design include light weight, easy installation, easy replacement, controlled damage locations, and minimum or no residual structural deformation. The disadvantage is that full energy dissipations can be achieved only when it is in tension. Therefore they will be effective in a frame structure only when cross bracings are used. This paper presents experimental tests and numerical simulation results to examine the effectiveness of this innovative brace member in mitigating seismic responses of frame structures. Laboratory cyclic loading tests on a single brace member and on steel frames without bracing or with cross bracing by conventional brace or segmented brace are carried out. The testing results are analyzed and compared. The effectiveness of segmented brace members in mitigation of seismic loading effects on frame structures is demonstrated. Nonlinear response analyses are then carried out to investigate the performance of this new segmented brace applied to a steel frame structure subjected to ground motions of different amplitudes. The results demonstrate that this new design is effective in mitigating seismic loading effect throughout the entire ground motion duration.

Comparative Study on the Effects of Infill Walls on Reinforced Concrete Frame Structures

2015 ◽  
Vol 730 ◽  
pp. 81-84
Author(s):  
Huan Jin
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Shear Failure ◽  
Frame Structure ◽  
Frame Structures ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Infill Walls ◽  
Finite Element Program ◽  
Static Test

Based on the quasi-static test of single-layer, two-bay RC frame model, using DIANA finite element program, a finite element Macro-model of masonry-infilled frame structure was established, and nonlinear finite element analysis of frame structures filled with different masonry materials was conducted. As a result of the existence of infill walls, the failure modes of frame structure have been changed, and which is easy to cause shear failure at the top of frame columns. If masonry materials of infill walls are different, the effects of infill panels on frame structures will be different. Comparative analysis shows that the influence of clay bricks is the largest, followed by autoclaved bricks’ influence, while aerated concrete blocks’ influence is the smallest. Therefore, to avoid the associated failure mechanism caused by infill walls, lightweight masonry materials are suggested to be used in actual engineering.

Literature Review of Precast Concrete Frame Structures in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 3-6
Author(s):  
Ke Wei Ding ◽  
Xiang Zhang
Keyword(s):  
Literature Review ◽  
Seismic Behavior ◽  
Civil Engineering ◽  
Precast Concrete ◽  
Engineering Application ◽  
Frame Structure ◽  
Frame Structures ◽  
Structure System ◽  
Concrete Frame ◽  
Performance Research

As construction industrialization is springing up in our country, precast concrete frame structure,as a result,has been developing rapidly. Based on a host of articles about precast concrete frame structure system at home and abroad,it,in this paper,summarized and prospected the latest stress performance research of precast concrete frame structure and up-to-date engineering application. Further more, total assembled node and seismic behavior of precast concrete frame structure is also pointed out as what is needed to study in the future.

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