Changes in dynamic characteristics of composites caused by the damage with fixed impact energy

One of the main functions of the steam turbine admission valve is to provide a very fast closing to intercept the supply of mass flow rapidly from the steam entering the turbine and cause destructive overspeed. In order to quickly close the admission valve, at the beginning of the stroke the moving parts of the valve should be accelerated to a high speed; when the stroke ends, a lot of kinetic energy is converted to impact energy. To prevent damage to valve parts, a quick closing buffer system is required to absorb the most of the impact energy. The quick closing buffer system plays an important role in the admission valve as an influencing factor of the dynamic characteristics of the valve. In the past, considering the complex internal structure, the research about quick closing buffer system relied on confirmatory experimental study or analytic method to get a quick closing buffer process. This paper focus on the quick closing process of a high pressure steam admission valve of Shanghai Turbine Plant. The dynamic characteristic of the quick closing buffer system is investigated by means of method of CFD numerical simulation for the first time, in order to find a more convenient and effective way to get the key factors that affect the dynamic characteristics, and the accuracy of the of CFD numerical simulation is verified by test, which are valuable for building an accurate dynamic characteristic analysis model of steam turbine admission valve.

Download Full-text

The Action of Irregular Waves on Ships Moored on Terminals

Journal of Energy Resources Technology ◽

10.1115/1.3230429 ◽

1982 ◽

Vol 104 (4) ◽

pp. 363-368

Author(s):

Yu-Cheng Li

Keyword(s):

Transfer Function ◽

Impact Energy ◽

Dynamic Characteristics ◽

Significant Relationship ◽

Wind Waves ◽

Ocean Waves ◽

Irregular Waves ◽

Directional Spectrum ◽

The Impact

For the analysis of the dynamic characteristics of ships moored at the offshore terminals under the action of wind waves, the moored ship system may be simplified to be linear. Introducing the transfer function Ye(ω), the impact energy of a moored ship on the terminal resulting from a random sea may be obtained from the spectrum of the ocean waves. Furthermore, by using the directional function of impact Y2(α), the directional spectrum of the impact by ships can also be estimated. The results show that there is a significant relationship between the spectrum of the ocean waves and the impact energy of the ship.

Download Full-text

Testing technique for jackhammers at the «СОРП» test bench

10.36652/0042-4633-2020-6-16-22 ◽

2020 ◽

pp. 16-22

Author(s):

V.S. Vanaev

Keyword(s):

Impact Energy ◽

Dynamic Characteristics ◽

Test Bench ◽

Operating Conditions ◽

Testing Technique ◽

Object Processing ◽

Energy Characteristics ◽

Bench Tests ◽

Processing Energy

A methodology for measuring the parameters of jackhammers at the «СОРП» test bench is presented, which is distinguished by metrological impeccability and correctness. All parameters are measured in the same nominal operating conditions, which was not provided by the previously used methods. Keywords jackhammer, bench, tests, manual machine, object, processing, energy characteristics, impact energy, dynamic characteristics. [email protected]

Download Full-text

Study on a collecting structure for impact energy and its dynamic characteristics

E3S Web of Conferences ◽

10.1051/e3sconf/202132901084 ◽

2021 ◽

Vol 329 ◽

pp. 01084

Author(s):

Kai Zhang ◽

Yongyong Zhu ◽

Qizheng Zhou

Keyword(s):

Energy Harvesting ◽

Impact Energy ◽

Dynamic Characteristics ◽

Output Voltage ◽

Structural Parameters ◽

System Dynamics Model ◽

Resonant Structure ◽

Dynamics Model ◽

System Output ◽

The Impact

The impact energy harvesting technology is studied in this paper, a piezoelectric harvesting structure with additional resonant structure including spring mass components is proposed, and the system dynamics model of the structure is studied. The influence of the structural parameters of spring mass block on the system output voltage is studied by using the model. The research results have certain application value for impact energy harvesting.

Download Full-text

Dynamic characteristics of linear induction motor for urban transit under constant V/f drive

Electrical Engineering in Japan ◽

10.1002/eej.4391100711 ◽

1990 ◽

Vol 110 (7) ◽

pp. 102-109

Author(s):

Sakutaro Nonak ◽

Nobuo Fujii ◽

Yasunobu Kojima

Keyword(s):

Induction Motor ◽

Dynamic Characteristics ◽

Urban Transit ◽

Linear Induction ◽

Linear Induction Motor

Download Full-text

Invited PaperTemperature dependence of SiGe HBT static and dynamic characteristics

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:1998319 ◽

1998 ◽

Vol 08 (PR3) ◽

pp. Pr3-81-Pr3-86

Author(s):

F. Aniel ◽

N. Zerounian ◽

A. Gruhle ◽

C. Mähner ◽

G. Vernet ◽

...

Keyword(s):

Dynamic Characteristics ◽

Static And Dynamic Characteristics ◽

Sige Hbt

Download Full-text

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

Metallurgical Research & Technology ◽

10.1051/metal/2018015 ◽

2018 ◽

Vol 115 (4) ◽

pp. 407 ◽

Cited By ~ 4

Author(s):

Annika Eggbauer Vieweg ◽

Gerald Ressel ◽

Peter Raninger ◽

Petri Prevedel ◽

Stefan Marsoner ◽

...

Keyword(s):

Mechanical Properties ◽

Impact Energy ◽

Charpy Impact ◽

Heat Treating ◽

Processing Route ◽

High Heating Rate ◽

Heating Rates ◽

High Heating ◽

Tempering Treatment ◽

Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Download Full-text