Identification of Energy Dissipation in Structural Joints by Means of the Energy Flow Analysis

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
S. S. Gómez ◽  
A. Metrikine ◽  
B. Carboni ◽  
W. Lacarbonara
Keyword(s):  
Experimental Data ◽  
Energy Dissipation ◽  
Energy Flow ◽  
Degrees Of Freedom ◽  
Flow Analysis ◽  
Low Frequency ◽  
Frequency Range ◽  
Energy Flow Analysis ◽  
Damping Matrix ◽  
Good Agreement

In this paper, identification of energy dissipation in the joints of a lab-scale structure is accomplished. The identification is carried out by means of an energy flow analysis and experimental data. The devised procedure enables to formulate an energy balance in the vicinity of the joints to obtain local energy dissipation. In this paper, a damping matrix based on the locally identified damping coefficients is formulated. The formulated damping matrix is later used in a five-degrees-of-freedom (5DOF) system for validation. The results obtained with the proposed method are in good agreement with the experimental data, especially in the low frequency range.

Collision–induced absorption in gaseous methane at low temperatures

1986 ◽  
Vol 64 (7) ◽  
pp. 763-767 ◽  
Author(s):  
I. R. Dagg ◽  
A. Anderson ◽  
S. Yan ◽  
W. Smith ◽  
C. G. Joslin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Low Temperatures ◽  
Low Frequency ◽  
Frequency Region ◽  
Experimental Results ◽  
Published Data ◽  
Frequency Range ◽  
Simple Method ◽  
Induced Absorption ◽  
Good Agreement

A recently developed theory for collision-induced absorption in methane is compared with experimental results over a wider spectral range and at lower temperatures than previously reported. The present experimental results covering the frequency range below 400 cm−1 exhibit good agreement with other recently published data. The theory shows excellent agreement with experiment in the low-frequency region below approximately 200 cm−1 but underestimates the experimental data somewhat at higher frequencies. Possible theoretical reasons for this discrepancy are given. The theory represents a simple method of obtaining a good estimate of the collision-induced absorption spectra of methane in this frequency region and for extrapolating to lower temperatures for which experimentation is not feasible. In addition, the moments α1 and γ1are compared with earlier determinations and indicate good agreement with the previously obtained values for the octupole and hexadecapole moments of methane.

The Energy Flow Analysis as a Tool for Identification of Damping in Tall Buildings Subjected to Wind: Contributions of the Foundation and the Building Structure

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
S. S. Gómez ◽  
A. V. Metrikine
Keyword(s):  
Energy Dissipation ◽  
Energy Flow ◽  
Flow Analysis ◽  
Tall Buildings ◽  
Specific Domain ◽  
Energy Flow Analysis ◽  
Modal Damping ◽  
Modes Of Vibration ◽  
Energy Dissipated ◽  
Half Power

In this paper, the energy dissipated in a tall building is identified by means of the energy flow analysis. This approach allows assessing energy dissipation within a specific domain or element of the structure. In this work, the focus is placed on the superstructure, which is the part of the building above the ground, and on the foundation. Damping operators for the superstructure and the foundation are formulated based on the identified energy dissipation in these parts of the building. The obtained damping operators are used to compute the modal damping ratios in a simplified model of the building. The modal damping ratios of the three lowest modes of vibration are compared to those identified in full-scale measurements by means of the half-power bandwidth method.

scholarly journals Development of Non-Conservative Joints in Beam Networks for Vibration Energy Flow Analysis

2007 ◽  
Vol 14 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Jee-Hun Song ◽  
Suk-Yoon Hong
Keyword(s):  
Energy Flow ◽  
Degrees Of Freedom ◽  
Vibrational Energy ◽  
Flow Analysis ◽  
Energy Flow Analysis ◽  
Internal Loss ◽  
Joint Properties ◽  
Flow Through ◽  
Coupled Structures ◽  
Coupling Angle

Our work aims to find a general solution for the vibrational energy flow through a plane network of beams on the basis of an energy flow analysis. A joint between two semi-infinite beams are modeled by three sets of springs and dashpots. Thus, the results can incorporate the case of complaint and non-conservative in all the three degrees of freedom. In the cases of finite coupled structures connected at a certain angle, the derived non-conservative joints and developed wave energy equation were applied. The joint properties, the frequency, the coupling angle, and the internal loss factor were changed to evaluate the proposed methods for predicting medium-to-high frequency vibrational energy and intensity distributions.

Energy flow analysis of straw-return agricultural modes in the Central Shaanxi Plain

2013 ◽  
Vol 20 (10) ◽  
pp. 1388-1393
Author(s):  
Bi JIANG ◽  
Fa-Qi WU ◽  
Xi-Hui WU ◽  
Ming LI ◽  
Xiao-Gang TONG
Keyword(s):  
Energy Flow ◽  
Flow Analysis ◽  
Energy Flow Analysis ◽  
Straw Return

Optimization-aided material and energy flow analysis for a low carbon industry

2017 ◽  
Vol 167 ◽  
pp. 1148-1154 ◽  
Author(s):  
Hendrik Lambrecht ◽  
Heidi Hottenroth ◽  
Tobias Schröer ◽  
Frank Schulenburg
Keyword(s):  
Energy Flow ◽  
Flow Analysis ◽  
Low Carbon ◽  
Energy Flow Analysis

Modeling of Multibody Flexible Articulated Structures With Mutually Coupled Motions: Part II — Application and Results

1992 ◽  
Author(s):  
Jiechi Xu ◽  
Joseph R. Baumgarten
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Open Loop ◽  
Body Motion ◽  
Universal Joint ◽  
Open Loop System ◽  
Numerical Examples ◽  
Kinematic Properties ◽  
Good Agreement

Abstract The application of the systematic procedures in the derivation of the equations of motion proposed in Part I of this work is demonstrated and implemented in detail. The equations of motion for each subsystem are derived individually and are assembled under the concept of compatibility between the local kinematic properties of the elastic degrees of freedom of those connected elastic members. The specific structure under consideration is characterized as an open loop system with spherical unconstrained chains being capable of rotating about a Hooke’s or universal joint. The rigid body motion, due to two unknown rotations, and the elastic degrees of freedom are mutually coupled and influence each other. The traditional motion superposition approach is no longer applicable herein. Numerical examples for several cases are presented. These simulations are compared with the experimental data and good agreement is indicated.

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