Influence of the Isolated Layer Damping Distribution of the Lateral-Torsional Coupling Isolated System on Earthquake Response

2011 ◽  
Vol 368-373 ◽  
pp. 1186-1191
Author(s):  
Xiang Zhen Li ◽  
Yi Feng Xie ◽  
Bing Li
Keyword(s):  
Dynamic Equations ◽  
Simplified Model ◽  
Earthquake Response ◽  
Dynamic Parameters ◽  
Structure Dynamic ◽  
Torsion Effect ◽  
Torsional Coupling

On the basis of the simplified model of lateral-torsional coupling isolated structure, dynamic equations of non-proportional damping isolated system of lateral-torsional coupling is established, and the influence of the isolated layer and the superstructure damping dynamic parameters on earthquake response is calculated and analyzed. The results show that, by reasonable adjustment of the damping distribution of the isolated layer, the torsion effect of the superstructure can be significantly reduced, and the basis displacement as well as rotation can be better suppressed, providing a basis for the design of the isolated layer damper reasonable distribution.

Study on Bending-Torsional Coupling Vibration of Intermediate Axis

2012 ◽  
Vol 166-169 ◽  
pp. 3180-3183
Author(s):  
Xue Shi Yao ◽  
Chun Long Zheng
Keyword(s):  
Torsional Vibration ◽  
Dynamic Equations ◽  
Optimized Design ◽  
Modal Shape ◽  
Bending Vibration ◽  
Coupling Vibration ◽  
Centrifugal Load ◽  
Torsional Coupling ◽  
Nature Frequency ◽  
Torsional Frequency

In order to find the cause of the cracked intermediate axis in a transmission,the characteristic of the bending vibration，torsional vibration and bending-torsional coupling vibration were studied through the analysis of the nature frequency and modal shape based on prestress.The results show that the fatigue fracture of the axis is mainly due to the resonant torsional frequency and bending-torsional coupling vibration and It is basically demonstrated by experiment.It has been found that the fundamental frequency is increase with the increase in spin axis velocity because of the centrifugal load i.e.prestress.The effets can be accounted for by an adjustment of the stiffness,and the dynamic equations are derived.In the end,it is made the optimized design on the axis,the low inherent frequencies are optimized in order to avoid resonance.The problem of the cracked intermediate axis has been solved.

Dynamic Modeling of Underwater Multi-Hull Vehicles

Robotica ◽  
2019 ◽  
Vol 38 (9) ◽  
pp. 1682-1702
Author(s):  
Roberta Ingrosso ◽  
Daniela De Palma ◽  
Giulio Avanzini ◽  
Giovanni Indiveri
Keyword(s):  
Dynamic Equations ◽  
Modular Approach ◽  
Dynamic Parameters ◽  
Nonlinear Dynamic Equations ◽  
Lumped Parameter ◽  
Control Reconfiguration ◽  
Ultimate Objective ◽  
Multi Body ◽  
Navigation Filters ◽  
Modular Nature

SUMMARYThis paper describes a modeling approach to compute the lumped parameter hydrodynamic derivative matrices of an underwater multi-hull vehicle. The vehicle, modeled as a multi-body underwater system and denoted as cluster, can be composed by heterogeneous bodies with known dynamic parameters, rigidly connected. The nonlinear dynamic equations of the cluster and its parameters are derived by means of a modular approach, based on the composition of single basic elements. The ultimate objective is to derive a mathematical description of the multi-hull system that captures its most significant dynamics allowing to design model-based motion controllers and navigation filters. The modular nature of the resulting model can be exploited, by example, when control reconfiguration is to be dealt with in the presence of (possibly multiple) failures. The numerical simulation of a hypothetical cluster is presented and discussed.

Design of a Robotic System that Plays with a Yoyo

1999 ◽  
Vol 11 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Koichi Hashimoto ◽  
◽  
Toshiro Noritsugu
Keyword(s):  
Energy Balance ◽  
Controller Design ◽  
Robotic System ◽  
Energy Balance Model ◽  
Dynamic Equations ◽  
Balance Model ◽  
Dynamic Parameters ◽  
Parameter Change ◽  
Highly Nonlinear ◽  
Event Driven

Yoyo dynamics are discontinuous and highly nonlinear, and dynamic parameters are difficult to estimate precisely. Some parameters even change their sign at the loop bottom of yoyo's trajectory. Humans predict parameter change timing visually and sense yoyo dynamics through the fingers. Designing a robot that plays with a yoyo is difficult due to a lack of sensors and dynamic equations for sensing yoyo movement. We propose eventbased formulation for this based on an energy balance model and event-driven control. Simulations and experiments verified the validity of formulation and controller design.

Feasibility Study on Forced Decoupling Method Analyzing Earthquake Response of Soil-Asymmetric Structure

2011 ◽  
Vol 368-373 ◽  
pp. 377-381
Author(s):  
Mei Li Wang ◽  
Jiao Xia Lan ◽  
Yan Hong Wang ◽  
Lei Yu Zhang
Keyword(s):  
Time Domain ◽  
Time Domain Analysis ◽  
Engineering Calculation ◽  
Earthquake Response ◽  
Asymmetric Structure ◽  
Direct Integral ◽  
Coupling Vibration ◽  
Decoupling Method ◽  
Matlab Program ◽  
Torsional Coupling

Time domain analysis on earthquake response of soil-asymmetric structure interaction system was carried out in this paper in order to study the feasibility of the forced decoupling method. Acoording to lateral-torsional coupling vibration equations of soil-asymmetric structure system, the direct integral MATLAB program in time domain were made used method. Feasibility of forced decoupling method was carried out by comparing the result in time domain with the result in frequency domain. Finally, it is derived that the results are very close to each other, which verify the feasibility of forced decoupling method. This conclusion can supply references to engineering calculation and design of structure.

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