Entropy squeezing for a generalized amplitude damping model

2021 ◽  
Vol 18 (12) ◽  
pp. 125202
Author(s):  
Zhi He ◽  
Bin-Yuan Huang ◽  
Jian-Jun Nie
Keyword(s):  
Entropy Squeezing ◽  
Amplitude Damping ◽  
Damping Model ◽  
Amplitude Damping Model

Anti-Seismic Energy Dissipation of Structures with Stress-Dependent Complex Damping with Consideration of Zero Amplitude Damping

2010 ◽  
Vol 163-167 ◽  
pp. 358-365
Author(s):  
Hui Dong Zhang ◽  
Yuan Feng Wang
Keyword(s):  
Energy Dissipation ◽  
Evaluation Method ◽  
Damping Ratio ◽  
Fuzzy Evaluation ◽  
Equivalent Viscous Damping ◽  
Amplitude Damping ◽  
Stress Dependent ◽  
Damping Theory ◽  
Damping Model ◽  
Complex Damping

Under most cases, the non-liner energy dissipation is approximately replaced with Rayleigh damping model which belongs to Maxwell-Kelvin type, the method is a fuzzy evaluation method of damping. Based on complex damping theory, equivalent dynamics equation of complex damping model is derived and loss factor is discussed, the accuracy of the equation is theoretically confirmed in this paper. Based on the existing damping theories, a new damping model is proposed, which is a zero amplitude damping model combing with stress dependent complex damping model. The model is used in seismic resistance analysis. Taking a steel beam for an example, the relationship between response amplitude and damping ratio is analyzed with the new damping model. It shows that the method of stress-dependent damping with consideration of zero amplitude damping can precisely describe the energy input and energy dissipation principles and the dynamic response under seismic loads can be precisely obtained. A solid foundation is laid for the further study of complex damping theory, its equivalent viscous damping model and engineering application.

A modified damping model of vector form intrinsic finite element method for high-speed spiral bevel gear dynamic characteristics analysis

2021 ◽  
pp. 030932472110188
Author(s):  
Xiangying Hou ◽  
Yuzhe Zhang ◽  
Hong Zhang ◽  
Jian Zhang ◽  
Zhengminqing Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Numerical Solutions ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Vector Form ◽  
Good Efficiency ◽  
Spiral Bevel ◽  
Damping Model

The vector form intrinsic finite element (VFIFE) method is springing up as a new numerical method in strong non-linear structural analysis for its good convergence, but has been constricted in static or transient analysis. To overwhelm its disadvantages, a new damping model was proposed: the value of damping force is proportional to relative velocity instead of absolute velocity, which could avoid inaccuracy in high-speed dynamic analysis. The accuracy and efficiency of the proposed method proved under low speed; dynamic characteristics and vibration rules have been verified under high speed. Simulation results showed that the modified VFIFE method could obtain numerical solutions with good efficiency and accuracy. Based on this modified method, high-speed vibration rules of spiral bevel gear pair under different loads have been concluded. The proposed method also provides a new way to solve high-speed rotor system dynamic problems.

scholarly journals CFD-DEM Simulation of Spouted Bed Dynamics under High Temperature with an Adhesive Model

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2276
Author(s):  
Zhao Chen ◽  
Lin Jiang ◽  
Mofan Qiu ◽  
Meng Chen ◽  
Rongzheng Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Particle Surface ◽  
Particle Collision ◽  
Gas Velocity ◽  
Spouted Bed ◽  
Dem Simulation ◽  
Linear Spring ◽  
Adhesion Model ◽  
Adhesive Model ◽  
Damping Model

Particle adhesion is of great importance to coating processes due to its effect on fluidization. Currently, Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) has become a powerful tool for the study of multiphase flows. Various contact force models have also been proposed. However, particle dynamics in high temperature will be changed with particle surface properties changing. In view of this, an adhesion model is developed based on approaching-loading-unloading-detaching idea and particle surface change under high temperature in this paper. Analyses of the adhesion model are given through two particle collision process and validated by experiment. Effects of inlet gas velocity and adhesion intensity on spouted bed dynamics are investigated. It is concluded that fluidization cycle will be accelerated by adhesion, and intensity of fluidization will be marginally enhanced by slight adhesion. Within a certain range, increasing inlet gas velocity will lead to strong intensity of particle motion. A parameter sensitivity comparison of linear spring-damping model and Hertz-Mindlin Model is given, which shows in case of small overlaps, forces calculated by both models have little distinction, diametrically opposed to that of large overlaps.

A novel squeezed-film damping model for MEMS comb structures

2017 ◽  
Author(s):  
Alexandre Sinding ◽  
Arnaud Parent ◽  
Ilker E. Ocak ◽  
Wajih U. Syed ◽  
Aveek N. Chatterjee ◽  
...  
Keyword(s):  
Damping Model
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