Uniform-load and actuator influence functions of a thin or thick annular mirror: application to active mirror support optimization

1996 ◽  
Vol 35 (7) ◽  
pp. 1095 ◽  
Author(s):  
Luc Arnold
1989 ◽  
Vol 21 (10-11) ◽  
pp. 1389-1402 ◽  
Author(s):  
R. Zaloum

Deviations from design expectations appear to stem from views which assume that a unique response should result from a given set of operating conditions. The results of this study showed that two systems operating at equal organic loads or F/M ratios and at the same SRT do not necessarily give equal responses. This deviation was linked to the manner in which the HRT and influent COD are manipulated to obtain a constant or uniform load, and to subtle interactions between influent COD, HRT and SRT on the biomass and effluent responses. Increases of up to 200% in influent COD from one steady level to the next did not significantly influence the effluent VSS concentration while an effect on filtered COD was observed for increases as low as 20%. Effluent TKN and filtered COD correlated strongly with the operating MLVSS while phosphorus residual depended on the operating SRT and the organic load removed. These results point to the inadequacy of traditional models to predict effluent quality and point to the need to consider these effects when developing simulation techniques or computer assisted expert systems for the control of waste treatment plants.


Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.


Actuators ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Kainan Wang ◽  
Thomas Godfroid ◽  
Damien Robert ◽  
André Preumont

This paper discusses the design and manufacturing of a thin polymer spherical adaptive reflector of diameter D=200 mm, controlled by an array of 25 independent electrodes arranged in a keystone configuration actuating a thin film of PVDF-TrFE in d31-mode. The 5 μm layer of electrostrictive material is spray-coated. The results of the present study confirm that the active material can be modelled by a unidirectional quadratic model and that excellent properties can be achieved if the material is properly annealed. The experimental influence functions of the control electrodes are determined by a quasi-static harmonic technique; they are in good agreement with the numerical simulations and their better circular symmetry indicates a clear improvement in the manufacturing process, as compared to a previous study. The low order optical modes can be reconstructed by combining the 25 influence functions; a regularization technique is used to alleviate the ill-conditioning of the Jacobian and allow to approximate the optical modes with reasonable voltages.


Author(s):  
Austin Fikes ◽  
Parham P. Khial ◽  
Samir Nooshabadi ◽  
Ali Hajimiri
Keyword(s):  

2014 ◽  
Vol 606 ◽  
pp. 229-232 ◽  
Author(s):  
Petr Tej ◽  
Vítězslav Vacek ◽  
Jiří Kolísko ◽  
Jindřich Čech

The paper focuses on a computer nonlinear analysis of the formation and development of cracks in a concrete slab exposed to a uniform continuous load on the lower surface. The analysis is based on an actual example of the formation and development of cracks in a basement slab exposed to ground water buoyancy.


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