Experimental Research on the Stability of Spatial Lattice Shell

2012 ◽  
Vol 204-208 ◽  
pp. 3048-3051
Author(s):  
Gan Tang ◽  
Wei Wei Li ◽  
Lin Feng Yin ◽  
Xiao Ming Guo

In the interest of an understanding to the imperfection stability behavior, a model of single layer spherical lattice shell was designed. The size and the pattern of initial imperfections were entirely measured. Automatic harmony loading control system and data acquisition system was used. The experiment plan, method and results have provided reference significance for the study on the stability of spatial lattice shell. The experimental results and the results of measured imperfections method were compared and analysed in detail. It is verified that measured imperfections method can accurately take into account of the effect of initial imperfections and it can be used for the supplementary checking computations of some important finished structures.

2012 ◽  
Vol 226-228 ◽  
pp. 1185-1189
Author(s):  
Jian Kang ◽  
Xiang Yu Liu

Radiant cable suspendome based on single-layer lattice shell is proposed in this paper whose cable-strut system is like that of Radiant Beam String Structure, the purpose of this paper is to do stability analysis of the structure.The linear buckling analysis of the hybrid structure and the single-layer lattice shell who has the same geometry parameters is carried out, we can preliminarily understand the stability of the hybrid structure. At the same time, nonlinear buckling analysis is carried out to study the stability of the hybrid structure under different rise-span ratios, different prestress level and half-span load. The results show that the introduction of prestressed cables greatly improve the structure's stability and reduce the structure sensitivity to original geometrical imperfection.


2021 ◽  
Author(s):  
Mingda Miao ◽  
Xueshan Gao ◽  
Jun Zhao ◽  
Peng Zhao

Abstract Background: In response to the current problem of low intelligence of mobile lower limb motor rehabilitation aids, this article proposes an intelligent control scheme based on human movement behavior in order to control the rehabilitation robot to follow the patient's movement. Methods: Firstly, a multi-sensor data acquisition system is designed according to the motion characteristics of human body. By analyzing and processing the motion data, the change law of human center of gravity and behavior intention are obtained, and the behavior intention of human is used as the control command of the robot following motion. In order to achieve the goal of the rehabilitation robot following human motion, an adaptive radial basis function neural network (ARBFNN) sliding mode controller is designed based on the robot dynamic model. The controller can reduce the impact of fluctuations in the human center of gravity on changes in the parameters of the robot control system, and enhance the adaptability of the system to other disturbance factors, and improve the accuracy of following human motion. Finally, the motion following experiment of the rehabilitation robot is carried out. Results: The experimental results show that the robot can recognize the motion intention of human body, and achieve the training goal of following different subjects to complete straight lines and curves. Conclusions: According to the experimental results, the accuracy of the multi-sensor data acquisition system and control algorithm design is verified, which demonstrates the feasibility of the proposed intelligent control scheme.


2014 ◽  
Vol 8 (1) ◽  
pp. 311-319 ◽  
Author(s):  
Zhang Zhonghao ◽  
Ma Huihuan ◽  
Fujimoto Masumi ◽  
Fu Qiang

Single layer two-way grid shell with in-plane and out-of-plane tension members is a new type of single-layer latticed shell roof. This study treats the effects of tension member installation on the buckling load and strength of a single layer two-way grid cylindrical shell roof by the numerical method. The tension members are installed to stiffen the rigidity of a single layer two-way grid shell roof and improve its stability behavior. Tension member installation and placement pattern is focused as both diagonal members of two-way grids and out-of-plane stiffened members in a cylindrical surface. The diagonal member and the out-of-plane member are used to increase the in-plane and the out-of-plane rigidity of a single layer two-way grid shell, respectively. The tension member placement pattern, the load distribution patterns, the initial imperfections and the initial axial force are considered for the numerical calculation parameters. It is confirmed by the numerical analysis that the tension members in out-of-plane and diagonals caused the increase in the buckling and strength of two-way grid shell.


2021 ◽  
Vol 16 (12) ◽  
pp. C12020
Author(s):  
A. Gioiosa ◽  
R. Bonventre ◽  
S. Donati ◽  
E. Flumerfelt ◽  
G. Horton-Smith ◽  
...  

Abstract The Mu2e experiment at the Fermilab Muon Campus will search for the coherent neutrinoless conversion of a muon into an electron in the field of an aluminum nucleus with a sensitivity improvement by a factor of 10000 over existing limits. The Mu2e Trigger and Data Acquisition System (TDAQ) uses otsdaq as the online Data Acquisition System (DAQ) solution. Developed at Fermilab, otsdaq integrates both the artdaq DAQ and the art analysis frameworks for event transfer, filtering, and processing. otsdaq is an online DAQ software suite with a focus on flexibility and scalability and provides a multi-user, web-based, interface accessible through a web browser. The data stream from the detector subsystems is read by a software filter algorithm that selects events which are combined with the data flux coming from a cosmic ray veto system. The Detector Control System (DCS) has been developed using the Experimental Physics and Industrial Control System (EPICS) open source platform for monitoring, controlling, alarming, and archiving. The DCS system has been integrated into otsdaq. A prototype of the TDAQ and the DCS systems has been built at Fermilab’s Feynman Computing Center. In this paper, we report on the progress of the integration of this prototype in the online otsdaq software.


2013 ◽  
Vol 788 ◽  
pp. 598-601
Author(s):  
Jun Qiang Wu ◽  
Yu Cui

This single-layer spherical reticulated shell has the advantages of reasonable stress,beautiful appearance ,fast construction,is widely applied in practical engineering. Through the static stability analysis of three kinds of single-layer spherical lattice shell structure using ansys, we get them in the uniform deformation under static load, the modal, buckling load. The results show that: The Kiewitt latticed shells displacement is small, structure is stable, better than SchwedLer and lianfang.


2011 ◽  
Vol 94-96 ◽  
pp. 868-871
Author(s):  
Wen Feng Du ◽  
Zhi Yong Zhou ◽  
Fu Dong Yu

Studies on the static stability and the ultimate bearing capacity of vierendeel latticed shells have been carried out. The buckling modal and the whole course of instability are shown using the Finite Element Method. The ultimate bearing capacity is compared with that of the single-layer latticed shell structure. The results show that the ultimate bearing capacity of the vierendeel latticed shells is 2.87 times more than that of the single-layer lattice shell in the condition of consuming the same steel. The vierendeel latticed shell structure not only has the advantages of concision and transparency like the single layer latticed shell structure, but also has the stability and carrying capacity like double-layer latticed shell structure.


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