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Wyszukujesz frazę "speed characteristics" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Vibration analysis of ball bearing considering waviness under high speed and an axial load
Autorzy:
Hou, P. P.
Wang, L. Q.
Peng, Q. Y.
Powiązania:
https://bibliotekanauki.pl/articles/201434.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rotational speed
ball bearing
vibration characteristics
frequency band
RMS
Opis:
Based on the rolling bearing vibration measurement principle in ISO standard, a nonlinear dynamic model of ball bearing is built and motion equations of the inner ring, outer ring, and rolling elements are derived by using Lagrange’s equation. The ball bearing model includes the influence of waviness, rotational speed, external load, arbor supporting stiffness and arbor eccentricity. Ball bearing high-speed vibration tests are performed and used to verify the theoretical results. Simulated results showed that specific waviness orders produced the principal frequencies that were proportional to rotational speed. Rotational speed mainly affected the value of the natural frequency of the bearing system, and RMS (Root Mean Square) of the full band had a great fluctuation with the increase of rotational speed. In the experiment, spectrum and RMS of 2 ƒs-30 kHz (ƒs : the rotational frequency of inner ring/arbor) under high speed could include not only the influence of rotational speed but also principal frequencies produced by waviness, which could cover the part of requirements of the standard bearing vibration measurement.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 517-527
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic characteristics of underframe semi-active inerter-based suspended device for high-speed train based on LQR control
Autorzy:
Wang, Yong
Li, Hao-Xuan
Meng, Hao-Dong
Wang, Yang
Powiązania:
https://bibliotekanauki.pl/articles/2173695.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamic characteristics
high-speed train
inerter-based suspended device
LQR control
Sperling index
charakterystyka dynamiczna
pociąg dużych prędkości
aktywne zawieszenie na bazie inertera
kontrola LQR
indeks Sperlinga
Opis:
The underframe passive inerter-based suspended device, based on the inerter-spring-damper vibration attenuation structure, could improve the dynamic performance of the train body, but its parameters are fixed and cannot meet the dynamic performance requirements under different operating conditions. Therefore, a semi-active inerter-based suspended device based on the linear quadratic regulator (LQR) control strategy is proposed to further enhance the dynamic performance. The rigid-flexible coupling vertical dynamic model of the train body and an underframe semi-active inerter-based suspended device are established. The structural parameters of the semi-active inerter-based suspended device are adjusted using LQR control strategy. Dynamic response of the system is obtained using the virtual excitation method. The dynamic characteristic of the system is evaluated using the Sperling index and compared with those of the passive and semi-active traditional suspended devices as well as the passive inerter-based suspended devices. The vertical vibration acceleration of the train body and Sperling index using the semi-active inerter-based suspended device is the smallest among the four suspended devices, which denotes the advantages of using the inerter and LQR control strategy. The semi-active inerter-based suspended device could decrease the vertical vibration acceleration of the train body and further suppress its elastic vibration in the lower frequency band, more effectively than the other three suspended devices. Overall, the semi-active inerter-based suspended device could significantly reduce elastic vibration of the train body and improve its dynamical performance.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 4; art. no. e141722
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical characteristics of ultra-shallow buried high-speed railway tunnel in broken surrounding rock during construction
Autorzy:
Hao, Shaoju
Fei, Ruizhen
Yu, Jia
Powiązania:
https://bibliotekanauki.pl/articles/2179933.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
skała pęknięta
skała otaczająca
posadowienie płytkie
kolej dużych prędkości
tunel
symulacja numeryczna
charakterystyka deformacji
broken rock
surrounding rock
ultra-shallow buried
high-speed railway
tunnel
numerical simulation
deformation characteristics
Opis:
The mechanical state of broken surrounding rock during the construction of ultra-shallow buried high-speed railway tunnel is very complicated, seriously affecting the construction safety. Taking Huying Xishan tunnel on Beijing-Shenyang Line as engineering background, MADIS/GTS NX numerical simulation and field test methods are used to analyze the characteristics of stress field, overall displacement, horizontal convergence of tunnel sidewalls and vault settlement during construction. The main mechanical characteristics of ultra-shallow buried high-speed railway tunnel with broken surrounding rock include: (1) After the stress redistribution, the stress concentration occurs at the boundary of the tunnel sidewall and surrounding rock, and the vertical displacement of tunnel vault and bottom appears obviously. (2) The horizontal displacement on both sides of the initial lining is obvious, while the horizontal displacement on the upper and lower support is small. The maximum lateral displacement of the initial lining is 1.71 cm, while the maximum vault settlement of the lower invert is 9.3 cm. (3) Both the horizontal convergence and the vault settlement increase with time. The growth rate is large in the early stage and tends to be stable in the later stage. (4) Compared with exponential and hyperbolic functions, the logarithmic function is most suitable for regression analysis of horizontal convergence and measured vault settlement data, and its fitting accuracy is higher than 90%.
Źródło:
Archives of Civil Engineering; 2022, 68, 3; 645--659
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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