Showing posts with label modelling. Show all posts
Showing posts with label modelling. Show all posts

Friday, 6 September 2013

Modelling and simulation of an Aramid rope system

A paper on rope system modelling, simulation and experimental validation is to be published at the 11th International Conference on Vibration Problems, Lisbon, Portugal, 9-12 September 2013


MODELLING, SIMULATION AND EXPERIMENTAL VALIDATION OF NONLINEAR DYNAMIC INTERACTIONS IN AN ARAMID ROPE SYSTEM
S. Kaczmarczyk, S. Mirhadizadeh, P. Picton, R. Salamaliki-Simpson, S. Turner
School of Science and Technology, The University of Northampton, UK 


Abstract. 
Vibration phenomena taking place in lifting and hoist installations may influence the dynamic performance of their components. For example, in an elevator system they may affect ride quality of a lift car. Lateral and longitudinal vibrations of suspension ropes and compensating cables may result in an adverse dynamic behaviour of the entire installation. Thus, there is a need to develop reliable mathematical and computer simulation models to predict the dynamic behaviour of suspension rope and compensating cable systems. The aim of this paper is to develop a model of an aramid suspension rope system in order to predict nonlinear modal interactions taking place in the installation. A laboratory model comprising an aramid suspension rope, a sheave/ pulley assembly and a rigid suspended mass has been studied. Experimental tests have been conducted to identify modal nonlinear couplings in the system. The dynamic behaviour of the model has been described by a set of nonlinear partial differential equations. The equations have been solved numerically. The numerical results have been validated by experimental tests. It has been shown that the nonlinear couplings may lead to adverse modal interactions in the system. 


REFERENCES
[1] R. Salamaliki-Simpson, S. Kaczmarczyk, P. Picton, S. Turner, "Non-linear Modal Interactions in a Suspension Rope System with Time-varying Length", Applied Mechanics and Materials 5-6 (2006) 217-224.
[2] S. Kaczmarczyk, "The Nonstationary, Nonlinear Dynamic Interactions in Slender Continua Deployed in High-rise Vertical Transportation Systems in the Modern Built Environment", Journal of Physics: Conference Series, Vol. 382 012037, doi:10.1088/1742-6596/382/1/012037 (2012).
[3] S. Kaczmarczyk, P. Picton, "The Prediction of Nonlinear Responses and Active Stiffness Control of Moving Slender Continua Subjected to Dynamic Loadings in a Vertical Host Structure", The International Journal of Acoustics and Vibration 18(1) (2013) 39-44. 

For more details please contact:
stefan.kaczmarczyk@northampton.ac.uk

seyed.mirhadizadeh@northampton.ac.uk

Details of the conference can be found at: http://www.icovp.com/index.php/programme

Saturday, 10 November 2012

Lifting and elevating modelling






  • Salamaliki-Simpson R, Kaczmarczyk S, Picton P, Turner S (2006) Non-Linear Modal Interactions in a Suspension Rope System with Time-Varying Length Journal of Applied Mechanics and Materials Vol. 5-6 pp 217-224 ISSN 1660-9336
Abstract:
This paper focuses on the investigation of the autoparametric coupling effects and modal
interactions in a suspension rope system with a time varying length. Equations of motion of a
multi-degree-of-freedom discrete, non-stationary and non-linear model are presented and are used to analyze the dynamic response of an elevator suspension rope system under resonance conditions. The equations of motion involve quadratic and cubic non-linear terms which are responsible for the modal interaction between the lateral and longitudinal oscillations of the rope and the car motions. The model takes into account the periodic excitations caused by motion of the host structure. The
results confirm that adverse responses may arise and internal autoparametric resonance phenomena
may occur

http://www.scientific.net/AMM.5-6.217



  • Terumichi Y, Kaczmarczyk S, Turner S, Yoshizawa M, Ostachowicz W (2003) Modelling, Simulation and Analysis Techniques in the Prediction of Non-stationary Vibration Response of Hoist Ropes in Lift Systems Materials Science Forums Vol. 440-441 pp 497-504





http://www.scientific.net/MSF.440-441.49

Saturday, 27 October 2012

Computational Model of Acute Pain


A Computational Model of Acute Pain 
Karen Prince, Jackie Campbell, Phil Picton, Scott Turner 

Paper available at: http://ducati.doc.ntu.ac.uk/uksim/journal/Vol-6/No.9/Paper1.pdf


Abstract: In 1965 Melzack and Wall proposed the influential gate control theory of pain.  This theory postulates that the substantia gelatinosa, located within the spinal cord, acts like a gating mechanism, which modulates the flow of information through the spinal cord to the brain and thus impacts on the pain experience. Subsequent research has, in general, supported this theory.  The explicitness of the theory and its well-defined architecture was translated into a mathematical model by Britton and Skevington in 1996.  However, the use of such modelling has been very limited in the field of pain.  

The fact that pain is still relatively a poorly understood phenomenon despite the abundance of literature that is available and because of the difficulty in obtaining some experimental data, suggest that it is an ideal candidate for mathematical modelling.  This paper successfully replicates the mathematical model as presented by Britton and Skevington.  It uses this as a platform to develop the model further to test some of the assumptions made in its original development and, more importantly, to produce a more biologically plausible model that can be used for further applications. 

Paper available at: http://ducati.doc.ntu.ac.uk/uksim/journal/Vol-6/No.9/Paper1.pdf

Wednesday, 3 October 2012

BCS events in October and November

A list of BCS events going on in Northampton and in surrounding areas:





Northampton Branch
4th October - Introduction to the world of Crypto https://events.bcs.org/book/159/ University of Northampton, 6:30pm


Bedford Branch
 4th October - Getting your business found in the search engines - what's new and what's important?
Bedford College, 6:00pm

27th November - The Way The Cookies Crumble - new website legal requirements http://www.bedfordtrainingservices.co.uk/cookies
Bedford College, 6:00pm



Hertfordshire Branch
10th October - The Perfect Storm: Population, Development & Climate Change http://www.herts.bcs.org/future.htm
University of Hertfordshire, 7:30pm