Dynamic behaviour of a bolted joint subjected to torsional excitation

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

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AN EXPERIMENTAL STUDY ON THE RELAXATION OF BOLTS

IIUM Engineering Journal ◽

10.31436/iiumej.v16i1.539 ◽

2015 ◽

Vol 16 (1) ◽

Cited By ~ 1

Author(s):

Muhammad Abid ◽

Muhammad Shahid Khalil ◽

Hafiz Abdul Wajid

Keyword(s):

Dynamic Behaviour ◽

Relaxation Behaviour ◽

Bolted Joint ◽

Factors Affecting ◽

Elastic Interactions ◽

Short And Long Term ◽

The Many ◽

Almost All ◽

Static Behaviour

Loss of pre-load with time, commonly known as â€˜Relaxationâ€™ is an established phenomena. Behaviour of a bolted joint depends upon the pre-load in the bolts in use, not the pre-load introduced by the mechanic. Loss of pre-load is expected due to the many factors such as embedment relaxation, gasket creep, elastic interactions, and vibration loosening or stress relaxation. In a gasketed joint, due to the gasket flexibility, relaxation is always substantial during preliminary passes, as 80 to 100% loss is not uncommon in almost all the bolts, resulting in a dynamic behaviour. Pre-load in a gasketed joint is stabilized and retained to certain extent in the final passes only. In a non-gasketed joint, due to no gasket and no rotation its static behaviour is concluded. This paper highlights the factors affecting the amount of relaxation with time and presents important considerations that can reduce this. Both the short and long term relaxations are recorded and a â€˜best fitâ€™ model for relaxation behaviour is derived.

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Some Dynamic Properties of Contact Patches in Bolted Joints

Volume 8: 29th Conference on Mechanical Vibration and Noise ◽

10.1115/detc2017-67008 ◽

2017 ◽

Author(s):

Damien P. T. Lancereau ◽

Hugh G. D. Goyder ◽

Philip Ind ◽

Daniel Brown

Keyword(s):

Dynamic Behaviour ◽

Dynamic Properties ◽

Relative Displacement ◽

Bolted Joints ◽

Nonlinear Behaviour ◽

Bolted Joint ◽

Clear Trend ◽

Contact Patch ◽

New Interpretation ◽

Instantaneous Frequencies

The dynamics of structures built-up from components connected by bolted joints are not well understood. Experiments were conducted with bolted joints in a shear configuration in which instantaneous vibration frequencies and damping could be measured. A system with bolted joints was excited and the free vibration decay measured. As the vibration decays, the damping decreases and the frequencies increase. This suggests a new interpretation for the contact patch in a bolted joint, involving bound, slipping and alternating regions. The changing size of the bound region controls the instantaneous frequencies and the relative displacement inside the slipping region and the alternating region controls the damping behaviour. Shims of different lengths enabled the behaviour of the contact patch to be investigated. A clear trend exists between the length of the shims and the non-linear dynamic behaviour. The introduction of multiple shims did not increase the damping or alter the dynamic nonlinear behaviour. The introduction of grease into the bolted joint increased the damping but oil did not. The vibration measurements enable the size of the contact patch to be estimated.

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Simplified model to study the dynamic behaviour of a bolted joint and its self loosening

STRUCTURAL ENGINEERING AND MECHANICS ◽

10.12989/sem.2015.55.3.639 ◽

2015 ◽

Vol 55 (3) ◽

pp. 639-654 ◽

Cited By ~ 2

Author(s):

Olfa Ksentini ◽

Bertrand Combes ◽

Mohamed Slim Abbes ◽

Alain Daidie ◽

Mohamed Haddar

Keyword(s):

Dynamic Behaviour ◽

Simplified Model ◽

Bolted Joint

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Investigation of fused silica dynamic behaviour

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2006134142 ◽

2006 ◽

Vol 134 ◽

pp. 929-934 ◽

Cited By ~ 2

Author(s):

F. Malaise ◽

J.-M. Chevalier ◽

I. Bertron ◽

F. Malka

Keyword(s):

Dynamic Behaviour ◽

Fused Silica

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A MODEL FOR THE FATIGUE SATURATION RANGE OF ALUMINIUM FROM DYNAMIC BEHAVIOUR AND INTERACTIONS OF DISLOCATIONS

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1987820 ◽

1987 ◽

Vol 48 (C8) ◽

pp. C8-155-C8-160

Author(s):

R. FOUGERES ◽

J. CHICOIS ◽

A. HAMEL ◽

A. VINCENT

Keyword(s):

Dynamic Behaviour

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Analysis of the Multi-Channel Epileptiform EEG Using the Markov Chains Formalism

Methods of Information in Medicine ◽

10.1055/s-0038-1635557 ◽

1989 ◽

Vol 28 (03) ◽

pp. 160-167 ◽

Cited By ~ 1

Author(s):

P. Penczek ◽

W. Grochulski

Keyword(s):

Dynamic Behaviour ◽

Joint Probability ◽

Drug Effects ◽

Anticonvulsant Drug ◽

Channel System ◽

Markov Network ◽

Eeg Data ◽

Multi Level ◽

Joint Probability Functions ◽

Dependent State

Abstract:A multi-level scheme of syntactic reduction of the epileptiform EEG data is briefly discussed and the possibilities it opens up in describing the dynamic behaviour of a multi-channel system are indicated. A new algorithm for the inference of a Markov network from finite sets of sample symbol strings is introduced. Formulae for the time-dependent state occupation probabilities, as well as joint probability functions for pairs of channels, are given. An exemplary case of analysis in these terms, taken from an investigation of anticonvulsant drug effects on EEG seizure patterns, is presented.

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