scholarly journals Dynamic performance estimation: A design tool for mechatronic scanners

2020 ◽  
Vol 53 (2) ◽  
pp. 8407-8412
Author(s):  
E. Csencsics ◽  
G. Schitter
Keyword(s):  
Dynamic Performance ◽  
Design Tool ◽  
Performance Estimation

Computer Analysis of Machines With Planar Motion: Part 2—Dynamics

1970 ◽  
Vol 37 (3) ◽  
pp. 703-712 ◽  
Author(s):  
B. Paul ◽  
D. Krajcinovic
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Performance ◽  
Transient Behavior ◽  
Basic Program ◽  
Design Tool ◽  
Multiple Degrees Of Freedom ◽  
Kinematic Loops ◽  
Long Term Behavior ◽  
Made In

A uniform procedure is described for establishing the dynamic equation of motion for machines with single or multiple degrees of freedom. The procedure, which utilizes the independent kinematic loops of the machine, is readily programmed for a digital computer. The basic program is largely independent of the specific machine being analyzed and is capable of treating input forces, internal springs and dampers, all of which may depend nonlinearly upon position, velocity, or time. As an example, the dynamic performance of a Stirling cycle engine is analyzed without recourse to simplifying approximations usually made in engine analysis (i.e., constant crank speed, use of approximate “rotating” and “reciprocating” weights, neglect of higher harmonics in piston motion). It is shown that the method not only predicts transient behavior, but is capable of predicting steady (long-term) behavior without loss of accuracy, or excessive computer costs. The method described satisfies the major criteria of generality, accuracy, and economy, required of a truly practical design tool.

Selection of One-Dimensional Design Parameter ‘Reaction Degree’ for 1st Stage of a Cooled Gas Turbine

2012 ◽  
Author(s):  
Hina Noor ◽  
Magnus Genrup ◽  
Torsten Fransson
Keyword(s):  
Mass Flow ◽  
Design Parameter ◽  
Design Tool ◽  
Performance Estimation ◽  
Design Parameters ◽  
Flow Angle ◽  
One Dimensional ◽  
And Performance ◽  
Reaction Degree ◽  
Selection Of

The recommendations available today in open literature for the choice of design parameter such as flow coefficient, stage loading and reaction degree incorporates mainly the influence of aerodynamics loss on efficiency. However, it is difficult to find the recommendation relating the influence of not only the aerodynamics loss but also cooling mass flow and cooling losses on varying most influential design parameters. In this paper, preliminary design and performance guidelines are presented for a cooled turbine stage using the 1D design tool LUAXT. The intention is to provide recommendations on the selection of design parameters, mainly reaction degree, which is found to be highly influenced by not only the aerodynamics loss but also the cooling mass flow and cooling loss such as in 1st stage of a High Pressure Turbines (HPT). The One-Dimensional (1D) design methods used to perform this task are verified and validated against experimental test data. A comparison of different loss models has been performed to provide most accurate outcomes for certain tested ranges. Based on the outcomes of this study, ‘Craig & Cox’ loss model has been considered to perform subsequent investigations for HPT design and performance estimation while formulating a parametric study. From this study, the design recommendations for the selection of performance parameter reaction degree are developed for cooled turbines. The results shows that for a HPT 1st stage, the recommended reaction degree range of 0.20 to 0.37 seems to provide the optimum stage design when chosen for stage loading in between 1.40 to 1.80 along with the stator exit flow angle in range of 74° to 78°.

DYNAMIC PERFORMANCES OF A RAILWAY BRIDGE UNDER MOVING TRAIN LOAD USING EXPERIMENTAL MODAL PARAMETERS

2010 ◽  
Vol 10 (01) ◽  
pp. 91-109 ◽  
Author(s):  
SUNG-IL KIM ◽  
NAM-SIK KIM
Keyword(s):  
Test Specimen ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Performance Estimation ◽  
Modal Testing ◽  
Modal Parameters ◽  
Vibration Exciter ◽  
Railway Bridge ◽  
Railway Bridges ◽  
Moving Train

In the design of railway bridges, it is necessary to be able to predict their dynamic behavior under a moving train load so as to avoid a resonance state from repetitive moving axle forces with uniform intervals. According to design trends, newly developed girder bridges weigh less and have longer spans. Since the dynamic interaction between bridge superstructures and passing trains is one of the critical issues concerning such railway bridges that are designed with greater flexibility, it is very important to evaluate the modal parameters of newly designed PSC girders before carrying out dynamic analyses. In this paper, a full scale incrementally prestressed 25-meter long concrete girder was fabricated as a test specimen and modal testing was performed at every prestressing stage in order to evaluate the modal parameters, including the natural frequency and the modal damping ratio. Young's modulus was also obtained from the global stiffness of the test specimen. During the modal testing, a digitally controlled vibration exciter and an impact hammer were applied in order to obtain precise frequency response functions, and the modal parameters were evaluated at various construction stages. With the availability of reliable properties from the modal experiments, dynamic performance estimation of a PSC girder railway bridge during the passage of a moving train can be carried out.

scholarly journals On dynamic performance estimation of fault-prone Infrastructure-as-a-Service clouds

2017 ◽  
Vol 13 (7) ◽  
pp. 155014771771851 ◽  
Author(s):  
Wanbo Zheng ◽  
Yuandou Wang ◽  
Yunni Xia ◽  
Quanwang Wu ◽  
Lei Wu ◽  
...  
Keyword(s):  
Cloud Computing ◽  
Analytical Approach ◽  
Virtual Machines ◽  
Dynamic Performance ◽  
Rejection Rate ◽  
Performance Estimation ◽  
Variable Load ◽  
Infrastructure As A Service ◽  
Trend Prediction ◽  
Prediction Approach

The cloud computing paradigm enables elastic resources to be scaled at run time satisfy customers’ demand. Cloud computing provisions on-demand service to users based on a pay-as-you-go manner. This novel paradigm enables cloud users or tenant users to afford computational resources in the form of virtual machines as utilities, just like electricity, instead of paying for and building computing infrastructures by their own. Performance usually specified through service level agreement performance commitment of clouds is one of key research challenges and draws great research interests. Thus, performance issues of cloud infrastructures have been receiving considerable interest by both researchers and practitioners as a prominent activity for improving cloud quality. This work develops an analytical approach to dynamic performance modeling and trend prediction of fault-prone Infrastructure-as-a-Service clouds. The proposed analytical approach is based on a time-series and stochastic-process-based model. It is capable of predicting the expected system responsiveness and request rejection rate under variable load intensities, fault frequencies, multiplexing abilities, and instantiation processing times. A comparative study between theoretical and measured performance results through a real-world campus cloud is carried out to prove the correctness and accuracy of the proposed prediction approach.

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