Dynamics Analysis of Energy Absorbing Device Based on Damped Dynamics Vibration Absorber

2015 ◽  
Vol 764-765 ◽  
pp. 254-258 ◽  
Author(s):  
Zhong Qiang Zheng ◽  
Peng Huang ◽  
Tao Yao ◽  
Zong Yu Chang
Keyword(s):  
Large Scale ◽  
Damping Ratio ◽  
Excitation Frequency ◽  
Tall Buildings ◽  
Analytical Form ◽  
Energy Absorber ◽  
In Series ◽  
Energy Transducer ◽  
Electrical Damping ◽  
Energy Absorbing

Nowadays, absorbing energy from vibration is one of the most promising technologies. In general, the vibrations may be very large, such as the vibrations of tall buildings, large flexible bridges, and ocean platform and so on in some environmental loading. With the global concern on energy and environmental issues, energy absorbing from large-scale vibrations for structural health monitoring purposes is more attractive and becomes a research frontier. A type of damped dynamics vibration energy absorber, where two masses are connected in series with the energy transducer and spring, is built and analyzed in this paper. The relationships among electrical damping ratio, excitation frequency ratio and dimensionless power are analyzed in frequency domain. The optimal parameters for maximizing the power output are discussed in analytical form while taking the parasitic mechanical damping of the system into account. In addition, the numerical simulations in time domain are calculated. The results indicate that when the system is excited by the larger peak of local optimal excitation frequency, more power can be obtained. It is helpful for design of energy absorber device.

ANALYSIS OF ENERGY ABSORBING DEVICE BASED ON DAMPED DYNAMIC VIBRATION ABSORBER

2016 ◽  
Vol 40 (4) ◽  
pp. 457-467
Author(s):  
Zhongqiang Zheng ◽  
Tao Yao ◽  
Peng Huang ◽  
Zongyu Chang
Keyword(s):  
Frequency Ratio ◽  
Large Scale ◽  
Damping Ratio ◽  
Excitation Frequency ◽  
Tall Buildings ◽  
Analytical Form ◽  
Dynamic Vibration Absorber ◽  
Energy Absorber ◽  
Electrical Damping ◽  
Energy Absorbing

Vibrations exist widely in tall buildings, vehicle systems, and ocean platform suffering from environmental loading such as wind, wave or earthquake. With the global concern on energy and environmental issues, energy absorbing from large-scale vibrations becomes a research frontier. A type of damped dynamics vibration energy absorber is built and analyzed in this paper, in which an added mass is connected to the vibration system with the electromagnetic transducer and spring. The relationships between electrical damping ratio, excitation frequency ratio and dimensionless power are analyzed in frequency domain. The optimal parameters for maximizing the power output are discussed in analytical form while taking the inherent mechanical damping of the system into account. The results indicate that when the system has suitable optimal excitation frequency ratio and damping ratio and so on, more power can be obtained. It is helpful for the design of energy absorber devices.

A Family of Efficient Sloshing Liquid Dampers for Suppression of Wind-Induced Instabilities

2003 ◽  
Vol 9 (3-4) ◽  
pp. 361-386 ◽  
Author(s):  
V. J. Modi ◽  
A. Akinturk ◽  
W. Tse
Keyword(s):  
Energy Dissipation ◽  
High Efficiency ◽  
Damping Ratio ◽  
Real Life ◽  
Wind Tunnel Test ◽  
Tall Buildings ◽  
Two Phases ◽  
Liquid Dampers ◽  
Obstacle Geometry ◽  
Floating Particles

Bluff structures in the form of tall buildings, smokestacks, control towers, bridges, etc., are susceptible to vortex resonance and galloping type of instabilities. One approach to vibration control of such systems is through energy dissipation using sloshing liquid dampers. In this paper we focus on enhancing the energy dissipation efficiency of a rectangular liquid damper through the introduction of two-dimensional obstacles as well as floating particles. The investigation has two phases. To begin with, a parametric free vibration study aimed at the optimization of the obstacle geometry is undertaken to arrive at configurations promising increased damping ratio and hence higher energy dissipation. The study is complemented by an extensive wind tunnel test program, which substantiates the effectiveness of this class of damper in suppressing both vortex resonance and galloping type of instabilities. Simplicity of design, ease of implementation, minimal maintenance, reliability as well as high efficiency make such liquid dampers quite attractive for real-life applications.

Analysis of nonlinear dynamic characteristic of a planetary gear system considering tooth surface friction

2021 ◽  
pp. 135065012199174
Author(s):  
Jingyue Wang ◽  
Ning Liu ◽  
Haotian Wang ◽  
Jiaqiang E
Keyword(s):  
Damping Ratio ◽  
Excitation Frequency ◽  
Planetary Gear ◽  
Gear System ◽  
Tooth Surface ◽  
Lumped Mass ◽  
Heavy Load ◽  
Light Load ◽  
Planetary Gear System ◽  
Bifurcation Behavior

Based on the lumped mass method, a torsional vibration model of the planetary gear system is established considering the nonlinear factors such as friction, time-varying meshing stiffness, backlash, and comprehensive error. The Runge–Kutta numerical method is used to analyze the motion characteristics of the system with various parameters and the influence of tooth friction on the bifurcation and chaos characteristics of the system. The numerical simulation results show that the system has rich bifurcation behavior with the excitation frequency, damping ratio, comprehensive error amplitude, load and backlash, and experiences multiple periodic motion and chaotic motion. Tooth friction makes the bifurcation behavior of the system fuzzy in the high frequency and heavy load areas, makes the chaos of the system restrained in the low-damping ratio and light load areas, advances the bifurcation point of the system in the small comprehensive error amplitude area, and makes the period window of the chaos area larger in the large-backlash area, which makes the bifurcation behavior of the system more complex.

Parameter Sensitivity Analysis of a Large-Scale System With Several Components Interacting in Series

1989 ◽  
Author(s):  
H. Torab
Keyword(s):  
Sensitivity Analysis ◽  
Large Scale ◽  
Optimization Problems ◽  
Parameter Sensitivity ◽  
Engineering Optimization ◽  
Parameter Sensitivity Analysis ◽  
Large Scale Systems ◽  
In Series ◽  
Special Case ◽  
Engineering Optimization Problems

Abstract Parameter sensitivity for large-scale systems that include several components which interface in series is presented. Large-scale systems can be divided into components or sub-systems to avoid excessive calculations in determining their optimum design. Model Coordination Method of Decomposition (MCMD) is one of the most commonly used methods to solve large-scale engineering optimization problems. In the Model Coordination Method of Decomposition, the vector of coordinating variables can be partitioned into two sub-vectors for systems with several components interacting in series. The first sub-vector consists of those variables that are common among all or most of the elements. The other sub-vector consists of those variables that are common between only two components that are in series. This study focuses on a parameter sensitivity analysis for this special case using MCMD.

Analytic Form Solution of the Direct Position Analysis of a Wide Family of Three-Legged Parallel Manipulators

2005 ◽  
Vol 128 (1) ◽  
pp. 264-271 ◽  
Author(s):  
Raffaele Di Gregorio
Keyword(s):  
Analytic Form ◽  
Parallel Manipulators ◽  
Analytical Form ◽  
Form Solution ◽  
Kinematic Chains ◽  
Position Analysis ◽  
In Series ◽  
The One ◽  
Generic Structures ◽  
Wide Family

A wide family of parallel manipulators (PMs) is the one that groups all PMs with three legs where the legs become kinematic chains constituted of a passive spherical pair (S) in series with either a passive prismatic pair (P) or a passive revolute pair (R) when the actuators are locked. The topologies of the structures generated by these manipulators, when the actuators are locked, are ten. Two out of these topologies are the SR-2PS topology (one SR leg and two PS legs) and the SP-2RS topology (one SP leg and two RS legs). This paper presents two algorithms. The first one determines all the assembly modes of the SR-2PS structures. The second one determines all the assembly modes of the SP-2RS structures. The presented algorithms can be applied without changes to solve, in analytical form, the direct position analysis (DPA) of all the parallel manipulators that generate a SR-2PS structure or a SP-2RS structure when the actuators are locked. In particular, the closure equations of two generic structures, one of type SR-2PS and the other of type SP-2RS, are written. The eliminants of the two systems of equations are determined and the solution procedures are presented. Finally, the proposed procedures are applied to real cases. This work demonstrates that (i) the DPA solutions of any PM that becomes a SR-2PS structure are at most eight, and (ii) the DPA solutions of any PM that becomes a SP-2RS structure are at most sixteen.

Analysis of Stochastic Nonlinear Dynamics in the Gear Transmission System with Backlash

2015 ◽  
Vol 16 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Jingyue Wang ◽  
Haotian Wang ◽  
Lixin Guo
Keyword(s):  
Time Course ◽  
Damping Ratio ◽  
Excitation Frequency ◽  
Period Doubling ◽  
Spur Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Stochastic Dynamic ◽  
Random Disturbance ◽  
Gear Transmission System

AbstractIn order to study the different backlash, gear damping ratio and random disturbance on dynamic behavior of gear transmission system, stochastic dynamic equations of the three-degree-of-freedom spur gear transmission system are established considering random disturbances of a low-frequency external excitation induced by torque fluctuation, gear damping ratio, gear backlash, excitation frequency and meshing stiffness. Using bifurcation diagram, phase diagram, time course diagram, Poincaré map and power spectrum of the system, the dynamic characteristics of the gear transmission system with different backlash under gear damping ratio changing, and the influence of the random disturbance of gear damping ratio on the bifurcation characteristic of system are analyzed. Numerical simulation shows that the gear transmission system will be from periodic motion with a noisy disturbance to chaotic-like motion by period-doubling bifurcation with decreasing gear damping ratio. In the small damping ratio range, the backlash has great effect on the motion characteristics. Random disturbance has an important effect on the bifurcation characteristics.

Modeling and analysis of impact energy absorber by using ls dyna

2015 ◽  
Vol 12 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Adik Yadao ◽  
R. S. Hingole
Keyword(s):  
Impact Energy ◽  
Material Properties ◽  
Research Work ◽  
Cad Model ◽  
Post Processing ◽  
Passenger Compartment ◽  
Efficient Manner ◽  
Energy Absorber ◽  
Modeling And Analysis ◽  
Energy Absorbing

Today’s car is one of the most important things in everyone’s life .Every person wants to have his or her own car but the question that arises in each buyer’s mind is whether the vehicle is safe enough to spend so much of money so it is the responsibility of an mechanical engineer to make the vehical comfortable and at the Same time safer. Now a days automakers are coming with various energy absorbing devices such as crush box, door beams etc. this energy absorbing device s prove to be very useful in reducing the amount force that is being transmitted to the occupant. In this we are using impact energy absorber in efficient manner as compare to earlier. The various steps involved in this project starting from developing the cad model of this inner impact energy absorber using the CAD software CATIA V5 R19. Then pre-processing is carried out in HYPERMESH 11.0 which includes assigning material, properties, boundary conditions such as contacts, constraints etc. LS-DYNA971 is used as a solver and LS-POST is used for the post processing and results obtained are compared to the standards. By carrying out this idea it has been observed that there is a considerable amount of energy that is being absorbed by this energy-absorbing device. Along with this energy absorption, the intrusion in passenger compartment is also reduced by considerable amount. So for safer and comfortable car with inner impact energy absorber is one of the best options available. This will get implement by this research work.

scholarly journals Optimum Shape and Position of Outrigger System for High Rise Building under Earthquake Loading

2020 ◽  
Vol 9 (3) ◽  
pp. 3268-3275
Keyword(s):  
Large Scale ◽  
Load Condition ◽  
Tall Buildings ◽  
Shear Walls ◽  
Optimum Shape ◽  
Earthquake Loading ◽  
High Rise ◽  
High Rise Building ◽  
Tall Structures ◽  
Earthquake Load

The advancement of high rise building has been increasing on a large scale. In tall structures shear wall often resisted the lateral load induced by wind and earthquake but as the building height increases the stiffness of the structure reduces. To provide sufficient lateral stiffness of the structure implementation of outrigger system between the shear walls and peripheral columns is often used. The aim of this study is to identify the optimum shape of outrigger belt truss in tall buildings under earthquake load condition. A thirty storey with single belt truss, forty five storeys with two belt trusses and sixty storey with three belt trusses structure was investigated with three different shape outrigger belt truss that is X, V and N. The optimum location by providing single belt truss at 10th story, 15th story and at top story in thirty story building is considered in the analysis. From the analysis a comparative study are made with and without variation of shape of outrigger with belt truss with parameters likes storey displacement and storey drift under earthquake loading and get a optimum position of outrigger belt truss for thirty storey building with single belt trusses placing at different locations.

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