Energy Dissipation by Micro-Slip in an Assembly, Analytic and Experimental Approach

2011 ◽  
Author(s):  
N. Peyret ◽  
J.-L. Dion ◽  
G. Chevallier ◽  
P. Argoul
Keyword(s):  
Loss Factor ◽  
Experimental Approach ◽  
Dynamic Behaviour ◽  
Dissipated Energy ◽  
Energy Losses ◽  
Non Linear ◽  
Definition Of ◽  
Linear Loss ◽  
Energy Dissipated ◽  
Experimental Bench

In structural dynamics, the problem of damping remains the biggest challenge. This paper deals with the energy losses caused by micro-slip in a planar interface of a structure. Taking into account friction in the joints during the analysis of dynamic systems remains a complex task. This paper proposes an analytical and experimental study of flexural vibrations of a clamped-clamped beam with innovative position of the interfaces. First, the benchmark is described and the choice of the position of the interface is justified. The displacement and stress fields are defined during each phase of the loading process in the joints under the assumption of quasi static motion. The energy dissipated by friction in the interface is calculated during a loading cycle. This leads to a definition of the dissipated energy, thus, to a non linear loss factor. The dynamic response of the beam is calculated using this non linear loss factor and a dissipative force is defined and used to predict the dynamic behaviour of the structure. In the last part of the paper, we present the experimental bench, and the dynamic behaviour of this structure. We propose to illustrate the mechanism of energy losses by micro-slip by making a comparison between the behaviour of the “monolithic” beam and the sectioned beam. Finally, we confront the loss factor calculated analytically and the measured one.

Non Linear Dynamic Behaviour Modelling of a Planar Friction Interface in a Structure Assembly

2009 ◽  
Author(s):  
N. Peyret ◽  
J.-L. Dion ◽  
G. Chevallier ◽  
P. Argoul
Keyword(s):  
Dynamic Systems ◽  
Loss Factor ◽  
Analytical Study ◽  
Dynamic Behaviour ◽  
Stress Fields ◽  
Non Linear ◽  
Definition Of ◽  
Linear Loss ◽  
Energy Dissipated ◽  
Structure Assembly

This paper deals with the energy losses caused by micro-slip in a planar interface of a structure. Taking into account friction in the joints during the analysis of dynamic systems remains difficult. This paper proposes an analytical study of flexural vibrations of a clamped-clamped beam, the novelty of this experiment is that the position of the interfaces has never been tested before to our knowledge. First, the authors described the benchmark and justified the choice of the position of the interfaces. The second section presents the displacement and stress fields during each phase of the loading process in the joints under the assumption of quasi static motion. In the third part, the authors calculated the energy dissipated by friction in the interface on a loading cycle. This leads to a definition of the energy dissipated by friction in the interface and thus to a non linear loss factor. This loss factor is then optimized according to the height of the beam. In the last part of the paper, the dynamic response of the beam is calculated using this non linear loss factor.

scholarly journals Dynamics of Assembled Structures: Taking Into Account the Surface Defects in Interfaces

2013 ◽  
Author(s):  
Nicolas Peyret ◽  
Gaël Chevallier ◽  
Jean-Luc Dion
Keyword(s):  
Loss Factor ◽  
Surface Defect ◽  
Test Bench ◽  
Surface Defects ◽  
Dissipated Energy ◽  
Energy Losses ◽  
Proposed Model ◽  
Nonlinear Loss ◽  
Energy Dissipated ◽  
Experimental Bench

In structural dynamics, the prediction of damping remains the biggest challenge. This paper deals with the energy losses caused by micro-slip in a nominally planar interface of a structure. This paper proposes an analytical and experimental study of flexural vibrations of a clamped-clamped beam with innovative position of the interfaces. The objective of this test bench is to characterize the global rheology of the interface. The proposed model aims to characterize this rheology based on local settings of the interface. First, the test bench is described and the choice of the position of the interface is justified. The experimental bench and the dynamic behavior of this structure are presented. We propose to illustrate the mechanism of energy losses by micro-slip by making a comparison between the behavior of a “monolithic” beam and a sectioned beam. Secondly, a modeling of the interface taking into account the surface defect is presented. The energy dissipated by friction in the interface is calculated during a loading cycle. This leads to a computation of the dissipated energy and thus to a nonlinear loss factor. Finally, we confront the loss factor calculated analytically and the measured one.

An Energy Approach for Helping the Selection of Solid Lubrication Coatings Under Fretting Conditions

2009 ◽  
Author(s):  
D. B. Luo ◽  
V. Fridrici ◽  
Ph. Kapsa ◽  
M. Taillandier ◽  
C. Prud’homme
Keyword(s):  
Master Curve ◽  
Initial Energy ◽  
Energy Approach ◽  
Friction Reduction ◽  
Solid Lubrication ◽  
Dissipated Energy ◽  
Test Parameters ◽  
Definition Of ◽  
Energy Dissipated ◽  
Fretting Damage

Employing friction reduction coatings is one of the most effective methods to palliate the fretting damage. However, facing numerous available coatings, how to compare them and select the optimum one for a specific application is still a challenging task. In this paper, based on the investigation of the fretting behaviors of several bonded solid lubricant coatings, an energy approach in terms of “initial maximal dissipated energy density” was suggested to compare the tribological response of coatings. According to test results, the lifetime of each coating under different test parameters can be fitted by one master curve. The definition of this master curve for a given coating may be used for the prediction of the coating lifetime only by knowing the initial energy dissipated in the contact. The comparison of different master curves for different coatings can be employed to help the coating selection.

scholarly journals A computational framework to establish data-driven constitutive models for time- or path-dependent heterogeneous solids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weijian Ge ◽  
Vito L. Tagarielli
Keyword(s):  
Constitutive Models ◽  
Computational Procedure ◽  
Data Driven ◽  
Dissipated Energy ◽  
Computational Framework ◽  
Heterogeneous Solids ◽  
Non Linear ◽  
Recorded Data ◽  
Path Dependent ◽  
Computational Homogenisation

AbstractWe propose and implement a computational procedure to establish data-driven surrogate constitutive models for heterogeneous materials. We study the multiaxial response of non-linear n-phase composites via Finite Element (FE) simulations and computational homogenisation. Pseudo-random, multiaxial, non-proportional histories of macroscopic strain are imposed on volume elements of n-phase composites, subject to periodic boundary conditions, and the corresponding histories of macroscopic stresses and plastically dissipated energy are recorded. The recorded data is used to train surrogate, phenomenological constitutive models based on neural networks (NNs), and the accuracy of these models is assessed and discussed. We analyse heterogeneous composites with hyperelastic, viscoelastic or elastic–plastic local constitutive descriptions. In each of these three cases, we propose and assess optimal choices of inputs and outputs for the surrogate models and strategies for their training. We find that the proposed computational procedure can capture accurately and effectively the response of non-linear n-phase composites subject to arbitrary mechanical loading.

MICRO-SLIP INDUCED DAMPING IN PLANAR CONTACT UNDER CONSTANT AND UNIFORM NORMAL STRESS

2010 ◽  
Vol 02 (02) ◽  
pp. 281-304 ◽  
Author(s):  
N. PEYRET ◽  
J.-L. DION ◽  
G. CHEVALLIER ◽  
P. ARGOUL
Keyword(s):  
Normal Stress ◽  
Loss Factor ◽  
Flexural Vibration ◽  
Bolted Joints ◽  
Stress Fields ◽  
Dissipated Energy ◽  
Stress And Strain ◽  
Loading Process ◽  
Nonlinear Loss ◽  
Planar Contact

The friction between interfaces at bolted joints plays a major role in the damping of structures. This paper deals with the energy losses caused by micro-slips in the joints. The aim of this study is to define in an analytical way these energy dissipation mechanisms which we examine through the analysis of a new benchmark: the flexural vibration of a clamped-clamped beam with original positioning of the interfaces. The joints exhibit the behavior of an interface under constant and uniform normal stress. The stress and strain values are computed at the joints under the assumption of quasi-static motion. This model allows us to understand the evolution of the slip and stick regions along the joint interfaces during the loading process. The expressions of the strain and stress fields during each phase of the loading process are derived. These lead to the quantification of the dissipated energy within the interface. Using this formula, a nonlinear loss factor can then be computed. In the final part of the paper, the dynamic response of the beam is calculated using this nonlinear loss factor.

The complex stiffnes method to detect and identify non-linear dynamic behaviour of SDOF systems

1989 ◽  
Vol 3 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. Mertens ◽  
H. Van der Auweraer ◽  
P. Vanherck ◽  
R. Snoeys
Keyword(s):  
Dynamic Behaviour ◽  
Linear Dynamic ◽  
Non Linear

The Static Aeroelasticity of Slender Configurations

1963 ◽  
Vol 14 (1) ◽  
pp. 75-104 ◽  
Author(s):  
G. J. Hancock
Keyword(s):  
Static Stability ◽  
Aerodynamic Forces ◽  
Flexible Aircraft ◽  
The Past ◽  
Plate Models ◽  
Non Linear ◽  
The Future ◽  
Static Aeroelasticity ◽  
Definition Of ◽  
Image Position

SummaryThe validity and applicability of the static margin (stick fixed) Kn,where as defined by Gates and Lyon is shown to be restricted to the conventional flexible aircraft. Alternative suggestions for the definition of static margin are put forward which can be equally applied to the conventional flexible aircraft of the past and the integrated flexible aircraft of the future. Calculations have been carried out on simple slender plate models with both linear and non-linear aerodynamic forces to assess their static stability characteristics.

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