scholarly journals Resonance reliability and importance measure analysis of multi-span pipe conveying fluid embedded in temperature-varying matrix

2021 ◽  
Vol 39 (5) ◽  
pp. 1035-1042
Author(s):  
Nan WU ◽  
Qing GUO ◽  
Guojun TONG ◽  
Yongshou LIU
Keyword(s):  
Optimization Design ◽  
Dynamic Stiffness ◽  
Importance Measure ◽  
Pipe System ◽  
System A ◽  
Fluid Flow Velocity ◽  
Measure Analysis ◽  
Velocity Pressure ◽  
Conveying Fluid ◽  
Measurement Index

Pipe system conveying fluid faces the problem of multi-order resonance failure caused by broadband excitation. For solving above problem, the dynamic stiffness method is employed to solve the dynamic equations of multi-span pipes considering the temperature effect. Combining the obtained natural frequency and the rule of resonance failure of pipe system, a multi-order anti-resonance system reliability model is established in this paper. To analyze the effect of input variable uncertainty on the probability of system resonance failure, the variance-based importance measurement index is further established. By introducing the active learning Kriging (ALK) model, the resonance failure probability and importance measurement index can be calculated efficiently. The effects of fluid flow velocity, pressure and temperature on the probability of pipe resonance failure are analyzed in detail, which has significant guidance for the anti-resonance optimization design of pipes.

Study on the Global Bifurcation of Quasi-Zero-Stiffness System

2013 ◽  
Vol 397-400 ◽  
pp. 451-456
Author(s):  
Qing Chao Yang ◽  
Li Hua Yang ◽  
Yan Ping Chen ◽  
Hao Kai Lai
Keyword(s):  
Optimization Design ◽  
Global Bifurcation ◽  
Mapping Method ◽  
Exciting Force ◽  
Force Frequency ◽  
Force Amplitude ◽  
System A ◽  
Wide Range ◽  
Chaos Motion ◽  
Dynamics Approximation

According to the characteristics of the quasi zero stiffness (QZS) system, a dynamics approximation model is established. The effect of excitation force amplitude, frequency and stiffness on the dynamic characteristics of the system is studied by continuation algorithm. The global bifurcation diagram with a wide range of parameters is achieved by using Poincaré mapping method. Results show that when the exciting force amplitude increases to a certain extent, the system will come into multi-cycle and chaos motion state. When exciting force frequency is lower, the system dynamic behavior is complicated, which is helpful for the engineering optimization design.

Prevention of neonatal hypothermia by a fiber optic “hot pipe” system: A new concept

1971 ◽  
Vol 6 (3) ◽  
pp. 354-358 ◽  
Author(s):  
Anthony Shaw ◽  
Irwin Franzel ◽  
Joseph Bordiuk
Keyword(s):  
Fiber Optic ◽  
Pipe System ◽  
System A ◽  
Neonatal Hypothermia

Target Optimization Design of Cam Curve in Zoom System

2013 ◽  
Vol 552 ◽  
pp. 44-51
Author(s):  
Chen Wei Ning ◽  
Cao Jian Zhong ◽  
Yang Hong Tao ◽  
Zhang Jian ◽  
Fan Zhe Yuan ◽  
...  
Keyword(s):  
Optimization Design ◽  
Rotation Angle ◽  
Optical Design ◽  
Zoom Lens ◽  
Pressure Angle ◽  
Cam Design ◽  
System A ◽  
Cam Follower ◽  
Optimization Function ◽  
The Stability

Zoom lens has been widely applied in all kinds of fields, and its cam optimization is the key to actualizing the performance of its optical design and the zooming process, while the smoothness and speediness of zooming movement must be considered for military and civilian use. With the incremental use of environmental requirements, it puts forward higher requests to the cam performance of lens. In order to guarantee that the cam has good stiffness in the case of vibration and shock environment, in the process of cam design, it not only requires curve optimal, but also needs to consider influence on the performance which is caused by reduced cam stiffness of the zoom system. A fine curve can ensure that the cam pressure angle α is smaller, and to ensure the cam follower maintains the uniform velocity and smaller acceleration in zooming process, and make the zoom system produce little impact, and whole zooming process smooth and fluent, it can reduce the zoom systems driving moment M, and can ensure the stability imaging of the zoom system. Good cam stiffness K can make the zoom lens have good stability in vibration environment, and make sure that the image quality. M and K respectively up to the pressure angle α of zoom curve and the rotation angle θ of zoom curve in cam. In the new cam design process, considering the whole influence on the performance that is caused by K and M to cam, we construct the function expressions K = f (α, θ) and M = f (α, θ), and then, build target optimization function with K and M, optimize the relationship between pressure angle α of zoom curve and rotation angle θ, looking for the optimal value for the stiffness K and the cam system driving moment M , and improve overall performance of the zoom cam .

Acoustic Optimization Design Method of Gear System

2014 ◽  
Vol 1016 ◽  
pp. 256-260
Author(s):  
Ze Yin He ◽  
Teng Jiao Lin ◽  
Wen Liu ◽  
Bo Liu
Keyword(s):  
Simulated Annealing ◽  
Optimization Design ◽  
Simulated Annealing Algorithm ◽  
Design Method ◽  
Gear System ◽  
Acoustic Properties ◽  
System A ◽  
Surface Method ◽  
Radiation Noise ◽  
Annealing Algorithm

The Response Surface Method (RSM) and Simulated Annealing Algorithm (SAA) are utilized to analysis and optimize the vibro-acoustic properties of gear system. A simple case is illustrated to demonstrate the capabilities of the acoustic optimization design method. The results show that the method of acoustic optimization design based on RSM and SAA can effectively reduce radiation noise, and provide theoretical fundament and guidance for further study on acoustic optimization design of complicated gear system.

Natural Steady Convection in a Space Annulus Between Two Elliptic Confocal Ducts: Influence of the Slope Angle

2005 ◽  
Vol 73 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Mahfoud Djezzar ◽  
Michel Daguenet
Keyword(s):  
Slope Angle ◽  
Boussinesq Equations ◽  
Annular Space ◽  
Arbitrary Angle ◽  
Elliptic Coordinates ◽  
System A ◽  
Pressure Formulation ◽  
Velocity Pressure ◽  
Steady Convection ◽  
Calculation Code

The authors express the Boussinesq equations of the laminar thermal and natural convection, in the case of permanent and bidimensional flow, in an annular space between two confocal elliptic cylinders. The latter is oriented at an arbitrary angle α with respect to the gravity force, using the elliptic coordinates system. A new calculation code using the finite volumes with the primitive functions (velocity-pressure formulation) is proposed. The Prandtl number is fixed at 0.7 (case of the air) with varying the Rayleigh number. The effect of the system inclination is examined.

scholarly journals Component importance in coherent systems with exchangeable components

2015 ◽  
Vol 52 (3) ◽  
pp. 851-863 ◽  
Author(s):  
Serkan Eryilmaz
Keyword(s):  
Importance Measure ◽  
Coherent System ◽  
Coherent Systems ◽  
System A ◽  
Component Importance

This paper is concerned with the Birnbaum importance measure of a component in a binary coherent system. A representation for the Birnbaum importance of a component is obtained when the system consists of exchangeable dependent components. The results are closely related to the concept of the signature of a coherent system. Some examples are presented to illustrate the results.

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