Prototype design and experimental tests of a zoom mirror system for the APS upgrade

2020 ◽  
Author(s):  
Xianbo Shi ◽  
Zhi Qiao ◽  
Sheikh T. Mashrafi ◽  
Ross Harder ◽  
Deming Shu ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Mirror System ◽  
Prototype Design

scholarly journals A FEM-Experimental Approach for the Development of a Conceptual Linear Actuator Based on Tendril’s Free Coiling

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Luca Cortese ◽  
Selena Milanovic ◽  
Renato Vidoni
Keyword(s):  
Experimental Approach ◽  
Experimental Tests ◽  
Nickel Titanium ◽  
Linear Actuator ◽  
The Finite Element Method ◽  
Actual Performance ◽  
Suitable Material ◽  
Working Principle ◽  
Set Up ◽  
Prototype Design

Within the vastness of the plant species, certain living systems show tendril structures whose motion is of particular interest for biomimetic engineers. Tendrils sense and coil around suitable grips, and by shortening in length, they erect the remaining plant body. To achieve contraction, tendrils rotate along their main axis and shift from a linear to a double-spring geometry. This phenomenon is denoted as the free-coiling phase. In this work, with the aim of understanding the fundamentals of the mechanics behind the free coiling, a reverse-engineering approach based on the finite element method was firstly applied. The model consisted of an elongated cylinder with suitable material properties, boundary, and loading conditions, in order to reproduce the kinematics of the tendril. The simulation succeeded in mimicking coiling faithfully and was therefore used to validate a tentative linear actuator model based on the plant’s working principle. More in detail, exploiting shape memory alloy materials to obtain large reversible deformations, the main tendril features were implemented into a nickel-titanium spring-based testing model. The results of the experimental tests confirmed the feasibility of the idea in terms of both functioning principles and actual performance. It can be concluded that the final set-up can be used as a base for a prototype design of a new kind of a linear actuator.

Research on Transmission Principle of Gearless Reducer

2013 ◽  
Vol 860-863 ◽  
pp. 1744-1747 ◽  
Author(s):  
Lin Wu ◽  
Ming Wang Dong
Keyword(s):  
Small Volume ◽  
High Efficiency ◽  
Raw Materials ◽  
Low Cost ◽  
Experimental Tests ◽  
Transmission Mechanism ◽  
Physical Prototype ◽  
First Time ◽  
Lateral Transmission ◽  
Prototype Design

Propose cylindrical cam lateral transmission mechanism for the first time, define the agency's three specific types. Design gearless reducer type A, B and C for construction elevator by the application of the agency to reducer industry. Conduct physical prototype processing manufacture based on cylindrical cam lateral transmission theory and virtual prototype design of gearless reducer. By contrast processing and experimental tests to determine that the theory of cylindrical cam lateral transmission mechanism is feasible. Gearless reducer have the advantage of high efficiency and energy saving, low cost, small volume, light weight, saving raw materials resources.

Concept of a new PZT

1978 ◽  
Vol 48 ◽  
pp. 271-278
Author(s):  
Chr. Kühne
Keyword(s):  
Mirror System ◽  
Measuring Instruments

The PZT according to MARKOWITZ, undoubtedly one of the most accurate measuring instruments, has become an integral part of astronomy in the last years. Yet there are two reasons why I still tried to improve the MARKOWITZ basic idea.For the MARKOWITZ process the use of a lens objective is imperative. Because of the diameter limitations of the lens objectives the magnitude is reduced. Although a 65 cm PZT has been put into operation in Washington recently, the thermal difficulties encountered made it necessary to control the temperature actively. In addition, the 65 cm diameter of a lens equipped with 4 elements can be considered as the very limit, but not for a mirror system.In addition there are still more disadvantages using lens objectives. The useable field is restricted by astigmatism, reducing the range of declination. The transmission, especially in the blue wavelengths, decreases very rapidly with the thickness of lenses. For large multilens objectives the transmission is less than for a mirror system.

Randomized Experimental Tests of Mediation Models

2011 ◽  
Author(s):  
Charles E. Lance ◽  
Richard P. DeShon ◽  
Eugene Stone-Romero
Keyword(s):  
Experimental Tests ◽  
Mediation Models

Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models

2000 ◽  
Vol 627 ◽  
Author(s):  
M. E. Swanson ◽  
M. Landreman ◽  
J. Michel ◽  
J. Kakalios
Keyword(s):  
Continuous Flow ◽  
Granular Media ◽  
Experimental Tests ◽  
Coarse Sand ◽  
Angle Of Repose ◽  
Flow Models ◽  
Maximum Angle ◽  
Stratification Effect ◽  
Upward Moving ◽  
Moving Layer

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

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