scholarly journals Investigations of dynamic characteristics of a tall industrial chimney due to light wind and solar radiation

2013 ◽  
Vol 12 (2) ◽  
pp. 087-094 ◽  
Author(s):  
Peter Breuer ◽  
Tadeusz Chmielewski ◽  
Piotr Górski ◽  
Eduard Konopka ◽  
Lesław Tarczyński
Keyword(s):  
Solar Radiation ◽  
Dynamic Characteristics ◽  
Field Tests ◽  
Power Station ◽  
Temperature Variations ◽  
Response Characteristics ◽  
Modal Damping ◽  
Wind Response ◽  
Satellite Signal ◽  
Air Temperature Variations

The present paper describes field tests conducted on the 300 m tall industrial chimney, located in the power station of Bełchatów (Poland), where the GPS rover receivers were installed at three various levels. The objectives of these GPS tests were to investigate the deformed vertical profile of this chimney, and its dynamic characteristics, i.e. the first natural frequency and the modal damping ratios. The results for the satellite signal receptions, the synopsis of recorded baselines and their ambiguity solutions, drifts of the chimney due to solar radiation and air temperature variations and dynamic wind response characteristics are presented.

scholarly journals Dynamic Characteristics Analysis with Multi-Directional Coupling in a TBM Mainframe

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Laikuang Lin ◽  
Yimin Xia ◽  
Zhengguang Li ◽  
Caizhang Wu ◽  
Yongliang Cheng ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Dynamic Characteristics ◽  
Field Tests ◽  
Fatigue Cracking ◽  
Tunnel Boring Machine ◽  
Dynamic Responses ◽  
Water Diversion ◽  
Practical Significance ◽  
Lumped Mass ◽  
Response Characteristics

AbstractThe cutterhead of a full-face rock tunnel boring machine (TBM) is constantly subjected to varying impact and dynamic loads during tunneling processes, resulting in relatively large vibrations that could easily lead to fatigue cracking of the entire machine and affect the tunneling performance and efficiency. To explore the dynamic characteristics of the TBM mainframe, a TBM from a water-diversion project is investigated in this research. According to the TBM vibration transmission route, an equivalent dynamic model of the TBM mainframe is established using the lumped-mass method in which the relevant dynamic parameters are solved. Additionally, the dynamic response characteristics of the TBM mainframe are analyzed. The results indicate that the vibration levels in three directions are approximately the same, the multi-directional vibration of the cutterhead is more intense than that of other components, and the vibration and external excitation exhibit identical change trends. A set of vibration field tests is performed to analyze the in situ dynamic responses of the mainframe and verify the correctness of the dynamic model. The theoretical and measured acceleration values of the TBM mainframe have the same magnitude, which proves the validity of the dynamic model and its solution. The aforementioned results provide an important theoretical value and practical significance for the design and assessment of the TBM mainframe.

A Study on the Scheduling of Large-Scaled PV Power Station Output based on Solar Radiation Forecast

2009 ◽  
Vol 129 (12) ◽  
pp. 1514-1521 ◽  
Author(s):  
Satoshi Takayama ◽  
Yuji Iwasaka ◽  
Ryoichi Hara ◽  
Hiroyuki Kita ◽  
Takamitsu Ito ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Power Station

scholarly journals Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies

2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Service Life ◽  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Field Tests ◽  
Vertical Load ◽  
Mathcad Software ◽  
The Mathematical Model

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.

Study on Flow-Induced Vibration Characteristics of Hydraulic Hoist of Large-Span Upwelling Radial Steel Gate

2011 ◽  
Vol 117-119 ◽  
pp. 241-246
Author(s):  
Zhen Hai Gao ◽  
Gen Hua Yan ◽  
Peng Liu ◽  
Fa Zhan Chen ◽  
Fei Ming Lv
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Characteristics ◽  
Vibration Response ◽  
Flow Induced Vibration ◽  
Structural Dynamic ◽  
Large Span ◽  
Response Characteristics ◽  
Lever Action ◽  
Structural Dynamic Characteristics ◽  
Steel Gate

In this paper we conduct study on flow-induced vibration of large-span upwelling radial steel Gate and its hydraulic hoist. Place an emphasis on vibration response characteristics under two working conditions of diversion and drainage, which proves the safety of hydraulic hoist gate vibration caused by gate vibration. Firstly, we study on dynamic characteristics of fluid-structure interaction of association system of gate and start and stop lever, reveals the discipline of the effect fluid having on structural dynamic characteristics. On this basis, flow-induced vibration characteristics under two conditions of with and without start and stop lever action considered. The results indicate that the gate vibration response with hydraulic hoist used decreases, which explains start and stop lever has certain effect of restraining vibration on gate vibration. In addition, under the working condition of drainage the vibration magnitude of start and stop lever is smaller than that of gate body, which explains there is damping action during transference of gate vibration through start and stop lever. The results find out that on the assumption of optimized gate structure and hydraulic arrangement, it is practicable, safe and reliable to adopt hydraulic hoist. The achievement has directive significance on similar projects construction in the future

Bioethanol Solar Reforming System for Distributed Fuel Cell

2014 ◽  
pp. 385-416
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Steam Reforming ◽  
Catalyst Layer ◽  
Efficiency Analysis ◽  
Heat Transfer Analysis ◽  
Heat Power ◽  
Response Characteristics ◽  
Thermal Output ◽  
Overall Efficiency

This chapter consists of two sections, ‘Hydrogen Production Characteristics of a Bioethanol Solar Reforming System with Solar’ and ‘Efficiency Analysis of a Combined PEFC and Bioethanol-Solar-Reforming System for Individual Houses’. Heat transfer analysis applied in reforming the catalyst layer of the reactor of FBSR (bioethanol steam reforming system) and the temperature distribution and transient response characteristics of the gas composition of the process are investigated in the 1st section The overall efficiency of the production of electricity and heat power of the FBSR system is determined by examining its thermal output characteristic in the 2nd section. It dependes for the overall efficiency of the system on the amount of solar radiation fluctuation rather than the amount of solar radiation.

Vibration Performance of Axially Graded Polymeric Viscoelastic Beams

2019 ◽  
Author(s):  
Mariona Heras Segura ◽  
Kumar Vikram Singh ◽  
Fazeel Khan
Keyword(s):  
Dynamic Performance ◽  
Spectral Characteristics ◽  
Polymeric Materials ◽  
Continuous Model ◽  
Viscoelastic Materials ◽  
Axial Distribution ◽  
Engineering Structures ◽  
Response Characteristics ◽  
Modal Damping ◽  
Vibration Performance

Abstract Structures having a non-homogenous axial distribution of geometrical and material parameters have shown marked improvements in their load carrying capacity, bucking and vibration characteristics. Viscoelastic polymeric materials inherently offer a combination of stiffness and damping which are dependent on frequency and temperature. Therefore, the vibration and dynamic behavior of such engineering structures can be manipulated by grading polymeric viscoelastic materials in a structure. In this research, the transverse vibration performance of an axially graded polymeric beam is considered through systematic modeling and optimization study. A piecewise continuous model has been developed for axially graded beams and their free vibration and frequency response characteristics were analyzed for different combination and grading schemes of polymeric materials. By spatially distributing the range of polymeric materials along the span, spectral characteristics (natural frequencies, modal damping) of graded beams are obtained. Numerical simulations are carried out with axially graded beams made of materials (PLA, ABS, Nylon and TPU) which are easily available for 3D printing. Their spectral characteristics were analyzed and it is demonstrated that frequency and damping characteristics can be manipulated with a prescribed axial distribution of viscoelastic materials. Hence they can be the basis for optimal structural design to achieve a desired dynamic performance.

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