scholarly journals Damping Energy Dissipation and Parameter Identification of the Bellows Structure Covered with Elastic-Porous Metal Rubber

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Guojian Shen ◽  
Min Li ◽  
Xin Xue
Keyword(s):  
Energy Dissipation ◽  
Dynamic Model ◽  
Constitutive Relation ◽  
Dynamic Properties ◽  
Porous Metal ◽  
Generalized Least Squares ◽  
Restoring Force ◽  
Metal Rubber ◽  
Vibration Parameters ◽  
Nonlinear Constitutive Relation

In order to improve damping energy dissipation of a U-shaped bellows structure, elastic-porous metal rubber as a cover layer was adopted and the corresponding vibration parameters were identified. First, the evolution of energy dissipation characteristics with respect to the changes of amplitude and frequency was investigated through a dynamic experimental test in the bending direction of the covered bellows structure. Second, the conspicuous hysteresis loop characteristics were described while the nonlinear constitutive relation was analytically modelled based on the exact decomposition method. Third, the corresponding parameters on dynamic properties of the covered bellows structure were determined by generalized least-squares estimation. Finally, the prediction results were compared with the measured displacement-restoring force curves to verify the accuracy of the developed dynamic model. The results indicate that the proposed dynamic model associated with the nonlinear constitutive relation for the covered bellows structure can well describe the evolution of the restoring force in terms of amplitude and frequency.

scholarly journals Nonlinear Dynamic Modelling of Two-Point and Symmetrically Supported Pipeline Brackets with Elastic-Porous Metal Rubber Damper

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1479
Author(s):  
Xue ◽  
Ruan ◽  
Li ◽  
Bai ◽  
Xiao
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Dynamic Modelling ◽  
Porous Metal ◽  
Nonlinear Damping ◽  
Pipeline System ◽  
Metal Rubber ◽  
Pipeline Vibration

This paper aims to investigate the nonlinear dynamic properties of a two-point and symmetrically supported pipeline bracket system coated with the damping element using an elastic-porous metal rubber. The dynamic model of the studied two-point and symmetric pipeline system was established based on impulse response matrix for accurate and reliable description on its nonlinear behaviours, e.g., energy dissipation and loss factor. The experimental verification of the developed model was performed by means of dynamic test as well as the analyses of nonlinear damping characteristics. The experimental results show a good agreement with the prediction results obtained from the proposed dynamic model. This work provides an alternative method to investigate the dynamics of pipeline vibration system equipped with a damping structure.

scholarly journals Energy Dissipation Characteristics and Dynamic Modeling of the Coated Damping Structure for Metal Rubber of Bellows

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 562 ◽  
Author(s):  
Kenan Wu ◽  
Hongbai Bai ◽  
Xin Xue ◽  
Tuo Li ◽  
Min Li
Keyword(s):  
Energy Dissipation ◽  
Vibration Amplitude ◽  
Test Results ◽  
Restoring Force ◽  
Hysteretic System ◽  
Large Size ◽  
Nonlinear Hysteretic System ◽  
Metal Rubber ◽  
Set Up ◽  
Nonlinear Elastic

A novel coated damping structure for metal rubber (MR) of bellows is designed based on large-size metal rubber sheets. This structure is dynamically tested in the bending direction at normal temperature. According to the test results, a model of the nonlinear elastic restoring force is set up, which describes the dynamic characteristics of the coated damping structure for metal rubber of bellows, and identifies the parameters of the model. The results show that the coated damping structure for metal rubber of bellows has a strong damping energy dissipation ability, its dynamic vibration characteristics are related to the vibration amplitude and frequency, and it is a complex nonlinear hysteretic system with multiple damping components. After identification of the parameters, the model of nonlinear elastic restoring force shows highly accurate results.

Design and Analysis of Viscoelastic Seismic Dampers

2002 ◽  
Author(s):  
N. Shimizu ◽  
H. Nasuno ◽  
T. Yazaki ◽  
K. Sunakoda
Keyword(s):  
Finite Element ◽  
Constitutive Relation ◽  
Time Domain ◽  
Dynamic Properties ◽  
Design Procedure ◽  
Fe Analysis ◽  
Damping Capacity ◽  
Element Formulation ◽  
Element Analysis ◽  
Equivalent Viscous Damping

This paper describes a methodology of design and analysis of viscoelastic seismic dampers by means of the time domain finite element analysis. The viscoelastic constitutive relation of material incorporating with the fractional calculus has been derived and the finite element formulation based on the constitutive relation has been developed to analyze the dynamic property of seismic damper. A time domain computer program was developed by using the formulation. Dynamic properties of hysteresis loop, damping capacity, equivalent viscous damping coefficient, and equivalent spring constant are calculated and compared with the experimental results. Remarkable correlation between the FE analysis and the experiment is gained, and consequently the design procedure with the help of the FE analysis has been established.

Nonlinear Dynamic Analysis of the Damping Frame Structure System

2012 ◽  
Vol 594-597 ◽  
pp. 886-890 ◽  
Author(s):  
Gan Hong ◽  
Mei Li ◽  
Yi Zhen Yang
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Time History ◽  
Time History Analysis ◽  
Frame Structure ◽  
Force Model ◽  
Operating Characteristics ◽  
Restoring Force ◽  
History Analysis

Abstract. In the paper, take full account of energy dissipation operating characteristics. Interlayer shear-frame structure for the analysis of the Wilson-Θmethod ELASTOPLASTIC schedule, the design of a nonlinear dynamic time history analysis procedure. On this basis, taking into account the restoring force characteristics of the energy dissipation system, the inflection point in the restoring force model treatment, to avoid a result of the calculation results of distortion due to the iterative error. A frame structure seismic response time history analysis results show that: the framework of the energy dissipation significantly lower than the seismic response of the common framework, and its role in the earthquake when more significant.

A convenient formulation of Sadowsky's model for elastic ribbons

2021 ◽  
Vol 477 (2255) ◽  
Author(s):  
Sébastien Neukirch ◽  
Basile Audoly
Keyword(s):  
Differential Equations ◽  
Constitutive Relation ◽  
Classical Problem ◽  
Constitutive Law ◽  
System Of Differential Equations ◽  
Dimensional Model ◽  
Simple Method ◽  
One Dimensional ◽  
Aspect Ratios ◽  
Nonlinear Constitutive Relation

Elastic ribbons are elastic structures whose length-to-width and width-to-thickness aspect ratios are both large. Sadowsky proposed a one-dimensional model for ribbons featuring a nonlinear constitutive relation for bending and twisting: it brings in both rich behaviours and numerical difficulties. By discarding non-physical solutions to this constitutive relation, we show that it can be inverted; this simplifies the system of differential equations governing the equilibrium of ribbons. Based on the inverted form, we propose a natural regularization of the constitutive law that eases the treatment of singularities often encountered in ribbons. We illustrate the approach with the classical problem of the equilibrium of a Möbius ribbon, and compare our findings with the predictions of the Wunderlich model. Overall, our approach provides a simple method for simulating the statics and the dynamics of elastic ribbons.

scholarly journals Closed-Form Solution of Road Roughness-Induced Vehicle Energy Dissipation

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
A. Louhghalam ◽  
M. Tootkaboni ◽  
T. Igusa ◽  
F. J. Ulm
Keyword(s):  
Energy Dissipation ◽  
Asymptotic Analysis ◽  
Closed Form ◽  
Dynamic Properties ◽  
Mechanistic Model ◽  
Closed Form Solution ◽  
Interaction Model ◽  
Form Solution ◽  
Dissipated Energy ◽  
Road Roughness

A major contributor to rolling resistance is road roughness-induced energy dissipation in vehicle suspension systems. We identify the parameters driving this dissipation via a combination of dimensional analysis and asymptotic analysis. We begin with a mechanistic model and basic random vibration theory to relate the statistics of road roughness profile and the dynamic properties of the vehicle to dissipated energy. Asymptotic analysis is then used to unravel the dependence of the dissipation on key vehicle and road characteristics. Finally, closed form expressions and scaling relations are developed that permit a straightforward application of the proposed road-vehicle interaction model for evaluating network-level environmental footprint associated with roughness-induced energy dissipation.

A Self-Deployment Hexapod Model for a Space Application

2008 ◽  
Vol 4 (1) ◽  
Author(s):  
G. Aridon ◽  
A. Al Majid ◽  
L. Blanchard ◽  
D. Rémond ◽  
R. Dufour
Keyword(s):  
Numerical Model ◽  
Dynamic Model ◽  
Strain Energy ◽  
The Self ◽  
Hysteretic Behavior ◽  
Simulation Tool ◽  
Space Application ◽  
Tensor Representation ◽  
Restoring Force ◽  
The Impact

This paper presents a simulation tool for predicting the self-deployment of an on-board deployable hexapod based on the release of strain energy stored in six tape-spring actuators. Their hysteretic behavior is described by six restoring force models, and a formulation of a direct dynamic model developed with a Lagrangian approach is performed. Furthermore, tensor representation is used to condense and simplify the calculation of Lagrangian partial derivatives. The results are compared with a numerical model that implements the recursive Newton–Euler technique. Finally, the impact of base excitations on the hexapod deployment performances is evaluated by using the proposed restoring force models.

scholarly journals Using Energy Dissipation Rate to Obtain Active Whitecap Fraction

2016 ◽  
Vol 46 (2) ◽  
pp. 461-481 ◽  
Author(s):  
Magdalena D. Anguelova ◽  
Paul A. Hwang
Keyword(s):  
Energy Dissipation ◽  
Dissipation Rate ◽  
Dynamic Properties ◽  
Length Distribution ◽  
Energy Dissipation Rate ◽  
Strength Parameter ◽  
Minimal Speed ◽  
Novel Approach ◽  
Decay Dynamic ◽  
Crest Length

AbstractActive and total whitecap fractions quantify the spatial extent of oceanic whitecaps in different lifetime stages. Total whitecap fraction W includes both the dynamic foam patches of the initial breaking and the static foam patches during whitecap decay. Dynamic air–sea processes in the upper ocean are best parameterized in terms of active whitecap fraction WA associated with actively breaking crests. The conventional intensity threshold approach used to extract WA from photographs is subjective, which contributes to the wide spread of WA data. A novel approach of obtaining WA from energy dissipation rate ε is proposed. An expression for WA is derived in terms of energy dissipation rate WA(ε) on the basis of the Phillips concept of breaking crest length distribution. This approach allows more objective determination of WA using the breaker kinematic and dynamic properties yet avoids the use of measuring breaking crest distribution from photographs. The feasibility of using WA(ε) is demonstrated with one possible implementation using buoy data and a parametric model for the energy dissipation rate. Results from WA(ε) are compared to WA from photographic data. Sensitivity analysis quantifies variations in WA estimates caused by different parameter choices in the WA(ε) expression. The breaking strength parameter b has the greatest influence on the WA(ε) estimates, followed by the breaker minimal speed and bubble persistence time. The merits and caveats of the novel approach, possible improvements, and implications for using the WA(ε) expression to extract WA from satellite-based radiometric measurements of W are discussed.

scholarly journals Energy Dissipation Characteristics and Parameter Identification of Symmetrically Coated Damping Structure of Pipelines under Different Temperature Environment

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1283
Author(s):  
Feng Jiang ◽  
Zheyu Ding ◽  
Yiwan Wu ◽  
Hongbai Bai ◽  
Yichuan Shao ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Hysteresis Loop ◽  
Least Square Method ◽  
Least Square ◽  
Test Results ◽  
Restoring Force ◽  
Dissipation Model ◽  
Effects Of Temperature ◽  
Dissipation Test ◽  
Metal Wires

In this paper, a symmetrically coated damping structure for entangled metallic wire materials (EMWM) of pipelines was designed to reduce the vibration of high temperature (300 °C) pipeline. A series of energy dissipation tests were carried out on the symmetrically coated damping structure at 20–300 °C. Based on the energy dissipation test results, the hysteresis loop was drawn. The effects of temperature, vibration amplitude, frequency, and density of EMWM on the energy dissipation characteristics of coated damping structures were investigated. A nonlinear energy dissipation model of the symmetrically coated damping structure with temperature parameters was established through the accurate decomposition of the hysteresis loop. The parameters of the nonlinear model were identified by the least square method. The energy dissipation test results show that the symmetrically coated damping structure for EMWM of pipelines had excellent and stable damping properties, and the established model could well describe the changing law of the restoring force and displacement of the symmetrically coated damping structure with amplitude, frequency, density, and ambient temperature. It is possible to reduce the vibration of pipelines in a wider temperature range by replacing different metal wires.

Comparative dynamic investigation of cross-laminated wooden panel systems: Shaking-table tests and analysis

2017 ◽  
Vol 21 (10) ◽  
pp. 1421-1436 ◽  
Author(s):  
Viktor Hristovski ◽  
Violeta Mircevska ◽  
Bruno Dujic ◽  
Mihail Garevski
Keyword(s):  
Energy Dissipation ◽  
Earthquake Engineering ◽  
Dynamic Properties ◽  
Seismic Energy ◽  
Experimental Tests ◽  
Shaking Table ◽  
Shaking Table Tests ◽  
Equivalent Viscous Damping ◽  
Cross Laminated Timber ◽  
Engineering Seismology

Cross-laminated timber has recently gained great popularity in earthquake-prone areas for construction of residential, administrative, and other types of buildings. At the Laboratory of the Institute of Earthquake Engineering and Engineering Seismology in Skopje, comparative full-scale shaking-table tests of cross-laminated timber panel systems have been carried out as a part of the full research program on the seismic behavior of these types of wooden systems, realized by Institute of Earthquake Engineering and Engineering Seismology, Skopje, and the Faculty of Civil and Geodetic Engineering (UL FCG), University of Ljubljana. Two different specimens built of cross-laminated timber panels have been tested: specimen containing a pair of single-unit principal wall elements (Specimen 1) and specimen containing a pair of two-unit principal wall elements (Specimen 2). In this article, the results from the shaking-table tests obtained for Specimen 2 and numerically verified by using appropriate finite element method–based computational model are discussed. Reference is also made to the comparative analysis of the test results obtained for both specimens. One of the most important aspects of the research has been the estimation of the seismic energy-dissipation ability of Specimen 1 and 2, via calculation of the equivalent viscous damping using the performed experimental tests. It is generally concluded that Specimen 2 exhibits a similar rocking behavior as Specimen 1, with similar energy-dissipation ability. Both specimens have manifested slightly different dynamic properties, mostly because Specimen 2 has been designed with one anchor more compared to Specimen 1. Forced vibration tests have been used for identification of the effective stiffness on the contacts for Specimen 2. This research is expected to be a contribution toward clarification of the behavior and practical design of cross-laminated timber panel systems subjected to earthquake loading.

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