A New Type of Hybrid-Passive-Damper

2010 ◽  
Vol 163-167 ◽  
pp. 4367-4372
Author(s):  
Ai Rong Liu ◽  
Qi Cai Yu ◽  
Yuan Yao ◽  
Yu Zhu Guo
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Loading Frequency ◽  
Vibration Period ◽  
Equivalent Damping ◽  
Passive Damper ◽  
New Type ◽  
Energy Dissipation Capacity ◽  
Relationship Of ◽  
The Relationship

This paper investigated the superelasticity and hysteresis characteristics of TiNi shape memory alloy ( SMA ) wire at room temperature, then the mechanical parameters of which were obtained. Based on the TiNi SMA wire and a purchased viscous damper, a new type of hybrid-passive-damper was designed and developed. Experiments were performed in order to validate the relationship of loading frequency and characteristic parameters such as energy dissipation capacity, equivalent damping ratio and equivalent stiffness. Experimental results show that hybrid-passive-damper designed in this paper has excellent energy dissipation capacity and is suitable for the vibration control of structures with long vibration period.

scholarly journals Estimation of Additional Equivalent Damping Ratio of the Damped Structure Based on Energy Dissipation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiuyan Hu ◽  
Qingjun Chen ◽  
Dagen Weng ◽  
Ruifu Zhang ◽  
Xiaosong Ren
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Theoretical Concept ◽  
Estimation Methods ◽  
External Excitation ◽  
Single Degree Of Freedom ◽  
Equivalent Damping ◽  
Seismic Motion ◽  
Practical Engineering ◽  
Energy Dissipation Capacity

In the design of damped structures, the additional equivalent damping ratio (EDR) is an important factor in the evaluation of the energy dissipation effect. However, previous additional EDR estimation methods are complicated and not easy to be applied in practical engineering. Therefore, in this study, a method based on energy dissipation is developed to simplify the estimation of the additional EDR. First, an energy governing equation is established to calculate the structural energy dissipation. By means of dynamic analysis, the ratio of the energy consumed by dampers to that consumed by structural inherent damping is obtained under external excitation. Because the energy dissipation capacity of the installed dampers is reflected by the additional EDR, the abovementioned ratio can be used to estimate the additional EDR of the damped structure. Energy dissipation varies with time, which indicates that the ratio is related to the duration of ground motion. Hence, the energy dissipation during the most intensive period in the entire seismic motion duration is used to calculate the additional EDR. Accordingly, the procedure of the proposed method is presented. The feasibility of this method is verified by using a single-degree-of-freedom system. Then, a benchmark structure with dampers is adopted to illustrate the usefulness of this method in practical engineering applications. In conclusion, the proposed method is not only explicit in the theoretical concept and convenient in application but also reflects the time-varying characteristic of additional EDR, which possesses the value in practical engineering.

A Study on Dynamic Properties of Cement-Stabilized Soils

2011 ◽  
Vol 243-249 ◽  
pp. 2050-2054 ◽  
Author(s):  
Pei Hsun Tsai ◽  
Sheng Huoo Ni
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Test Results ◽  
Resonant Column Test ◽  
Stabilized Soil ◽  
Shearing Strain ◽  
Relationship Of ◽  
The Relationship

In this paper the dynamic property (shear modulus and damping ratio) of cement-stabilized soil is studied with using the resonant column test. The amount of cement admixed, the magnitude of confining pressure, and shearing strain amplitude are the parameters considered. Test results show that the maximum shear modulus of cement-stabilized soil increases with increasing confining pressure, the minimum damping ratio decreases with increasing confining pressure. The shear modulus of cement-stabilized soil decreases with increasing shearing strain while the damping ratio increases with increasing shearing strain. In the paper the relationship of shear modulus versus shearing strain is fitted into the Ramberg-Osgood equations using regression analysis.

Research on the Method of Circumferential Spring Dual Mass Flywheel Damper Matching with Diesel Engine

2009 ◽  
Vol 419-420 ◽  
pp. 65-68
Author(s):  
Zheng Feng Jiang ◽  
Lei Chen
Keyword(s):  
Diesel Engine ◽  
Torsional Vibration ◽  
Torsional Stiffness ◽  
Vibration Damper ◽  
Passenger Car ◽  
Inertia Coefficient ◽  
New Type ◽  
Working Principle ◽  
Relationship Of ◽  
The Relationship

As a new type of torsional vibration damper, a Dual Mass Flywheel (DMF) has different configuration and working principle from the traditional clutch. Focusing on the problem of matching DMF with a diesel engine, the relationship of circumferential spring dual mass flywheel (CS-DMF) and gearbox is analyzed based on a multi-freedom model, and then the methods of gearbox selection, rotary inertia coefficient ascertain and optimization of torsional stiffness are proposed in this paper. The methods have been applied to a CS-DMF matching with a passenger car with diesel engine. Modal simulation and torque fluctuating experiment show the CS-DMF has excellent damping performance.

scholarly journals Effects of Damping Uncertainties on Damping Reduction Factors

2016 ◽  
Vol 61 (2) ◽  
pp. 341 ◽  
Author(s):  
Baizid Benahmed ◽  
Malek Hammoutene ◽  
Donatello Cardone
Keyword(s):  
Monte Carlo ◽  
Energy Dissipation ◽  
Dynamic Response ◽  
Design Process ◽  
Coefficient Of Variation ◽  
Damping Ratio ◽  
Response Spectra ◽  
Energy Dissipation Capacity ◽  
Damping Estimation ◽  
Reduction Factors

It is apparent that the dynamic response of a building dependson its energy dissipation capacity, hence damping ratio. Thedamping value experienced by a building during an earthquakediffers significantly from the value specified in the design step.This introduces uncertainties in the design process of the building.It would be desirable to consider not only the effects ofuncertainties in loading but also the uncertainties in the structuralparameters. In this paper, the effects of uncertainties in the estimation ofdamping ratio ξ, on the use of Damping Reduction Factors (DRF) for the evaluation of high damping response spectra,are examined. Damping uncertainties are described by a lognormalprobability distribution, and the Monte Carlo techniqueis used to generate the random values of damping. Theaverage of the distribution is the deterministic value of damping (taken equal to 5%, 7.5%, 10%, 20%, 30% and 40%) whilethree different values of coefficient of variation are considered (i.e. 10%, 20% and 40%, respectively). All the DRF formulations found in the literature are not able totake into consideration damping uncertainties, leading to significantdiscrepancies in the high damping response spectra. Based on the results of this study, a new DRF formulation, ableto account for uncertainties in damping estimation, is tentatively proposed.

Translation Motion and Dynamic Analysis of Ancient Architecture

2012 ◽  
Vol 253-255 ◽  
pp. 3-7
Author(s):  
Tie Cheng Wang ◽  
Liang Zhang ◽  
Hai Long Zhao
Keyword(s):  
Energy Dissipation ◽  
Free Vibration ◽  
Dynamic Analysis ◽  
Dynamic Force ◽  
Vibration Period ◽  
Translation Motion ◽  
Energy Dissipation Capacity ◽  
The Right ◽  
Jacking Force ◽  
The Temple

Reasonable formula of jacking force and scientific dynamic analysis has an important contribution to guide the building monolithic moving Engineering. In this paper, take the temple as an example to study building monolithic movement. It is shown in the analysis results of SAP2000 that the mortise-tenon joints (in the wooden structure) has a significant influence in improving the energy dissipation capacity, prolonging the structural free vibration period,minimizing the dynamic response of structure. The acceleration of all the joints tends to be in consistent under the dynamic force effect. The structure has enough safety capacity within the right displacement margin for joints.

Mechanical Behavior and Failure Patterns of SMA Structural Functional Materials

2013 ◽  
Vol 591 ◽  
pp. 159-163
Author(s):  
Huai Liang Zhu ◽  
Li Feng Yu ◽  
Si Hui Liang ◽  
Chao Qun Ni
Keyword(s):  
Energy Dissipation ◽  
Ductile Failure ◽  
Functional Materials ◽  
Experimental Methods ◽  
Dissipation Factor ◽  
Mechanical Behaviors ◽  
Failure Patterns ◽  
Niti Sma ◽  
Relationship Of ◽  
The Relationship

This paper presents an approach to investigate the mechanical properties and failure patterns of shape memory alloy (SMA) by experimental methods. Tests were carried out under the conditions of uniaxial tension, cycling loading and impact-tension respectively. The mechanical behaviors of NiTi SMA such as the relationship of stress-stain, super-elasticity, high damping, energy dissipation and tension-shock toughness are discussed in detail. In addition, the destroy patterns of SMA materials are analyzed for varying condition of testing. Whether ductile failure or brittle fracture is decided to do much with the testing styles and strain rate of materials. It is shown that with the large restoring deformation, higher energy dissipation factor and tension-shock toughness, so NiTi SMA structural functional materials are very suitable for vibration control in engineering.

scholarly journals The Pivotal Meaning and Its Relationship with Derivation Al Tahqiq fe AlQuran Al-Kareem. A Sample (Scrutinizing Words in Glorious Quran: A Sample)

2018 ◽  
Vol 212 (1) ◽  
pp. 211-240
Author(s):  
Assist. Prof. Dr. Khamis Abdullah Al-Timimy. ◽  
Dr. Haider Shnawa Faisal Al-zaidi.
Keyword(s):  
New Type ◽  
Points Of View ◽  
The Difference ◽  
Central Meaning ◽  
Relationship Of ◽  
The Relationship

The Paper has tackled the pivotal meaning, its relationship with derivation, and its types. The paper starts with defining the pivotal meaning and the ways of its formation, then mentioning the difference between the pivotal meaning and central meaning with revealing the most significant points of view anciently and recently. The researcher has defined derivation mentioning the essential views that have said about it with providing on adequate exposure to Mustafawi's remarks concerning derivation and hid unique achievement in this field i.e. adding a new type of derivation which he calls "extractive derivation". The researcher has also tackled about the relationship of the pivotal meaning with types of derivation represented by: small, big, the biggest, and magnificent. Keeping in mind that derivation is a linguistic procedure which cannot be restricted in specific limits in addition to the fact that its relation with the pivotal meaning is divergent depending on the type of derivation. 

Effect of Electromagnetic Force on Dynamic Mechanical Properties of the Magnetorheological Elastomer Under Compression Mode

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Xinxin Shi ◽  
Shaogang Liu ◽  
Dan Zhao ◽  
Zhenghang Zhao ◽  
Jin Cui ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Strain Amplitude ◽  
Electromagnetic Force ◽  
Dynamic Mechanical Properties ◽  
Loading Frequency ◽  
Magnetorheological Elastomer ◽  
Change Rate ◽  
Dynamic Mechanical ◽  
Energy Dissipation Capacity

Abstract Under the compression mode, the direction of force on the magnetorheological elastomer (MRE) is parallel to the direction of electromagnetic force, so the effect of electromagnetic force on its dynamic mechanical properties cannot be ignored. Therefore, this paper focuses on the effect of electromagnetic force on the dynamic mechanical properties of MRE under compression mode. A new type of testing device was designed and processed. Under a different loading frequency, strain amplitude and external magnetic field, dynamic mechanical properties of MRE were tested, respectively. The result shows that the stiffness and energy dissipation capacity of MRE increase with the current and loading frequency. The stiffness of MRE decreases with the increase in the strain amplitude, but the energy dissipation capacity increases. Comparing the force-displacement curve of MRE with or without the effect of the electromagnetic force, it shows that the electromagnetic force has a great effect on the stiffness of MRE and little effect on its energy dissipation capacity. When the electromagnetic force is removed, the stiffness of MRE decreases, and the change rate of stiffness increases with current. The maximum change rate of stiffness is 5.65%.

scholarly journals Hysteretic Behavior of Beam-to-Column Joints with Cast Steel Connectors

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Guofeng Xue ◽  
Wei Bao ◽  
Jin Jiang ◽  
Yongsong Shao
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Cast Steel ◽  
Hysteretic Behavior ◽  
Element Analysis ◽  
Rapid Repair ◽  
Practical Engineering ◽  
New Type ◽  
Column Joint ◽  
Energy Dissipation Capacity

This study proposed a beam-to-column joint equipped with a new type of cast steel connector. The cast steel connector concentrated the primary portion of the deformation and energy dissipation of the joint and was installed with full bolted connections, rendering it a replaceable energy dissipation component and facilitating the rapid repair of the joint after an earthquake. Three full-scale specimens were fabricated and tested to investigate the hysteretic behaviors of the proposed joints under cyclic loadings. The results showed that the proposed cast steel connector exhibited reliable ductility and energy dissipation capacity. The beam-to-column joints with cast steel connectors under appropriate configuration can limit the deformation to the cast steel connector and protect the remaining joint components from plastic deformation. A more detailed finite element analysis was performed to investigate the hysteretic behavior of the joint further. The FEM results illustrated that the thickness of the vertical leg of the cast steel connector can significantly influence the stiffness and bearing capacity of the joint. Meantime, it would improve the hysteretic behavior effectively. The proposed beam-to-column joints with cast steel connectors can achieve the requirement of stiffness and load-bearing capacity and can be widely applicable in practical engineering.

Shocks and energy dissipation in inviscid fluids: a question posed by Lord Rayleigh

1997 ◽  
Vol 347 ◽  
pp. 375-380 ◽  
Author(s):  
JAMES E. BROADWELL
Keyword(s):  
Energy Dissipation ◽  
Turbulent Flows ◽  
Compression Wave ◽  
Inviscid Fluid ◽  
One Dimensional ◽  
Inviscid Fluids ◽  
Relationship Of ◽  
The Relationship

Lord Rayleigh argued that after a discontinuity develops in a one-dimensional compression wave in an ideal inviscid fluid some sort of motion must continue. Arguments are given in support of this view and a suggestion is made as to what that motion might be. The relationship of this motion to that proposed by Onsager for incompressible inviscid turbulent flows is discussed.

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