Dissertation Defenses

Doctoral Dissertation Announcement

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Candidate: Jai Thomas

Degree of: Doctor of Philosophy

Department: Industrial and Manufacturing Engineering

Title: Using a Torsional Stiffness Curve in a Simulation Model to Predict Brake Hose Shape

Committee:
Dr. Mitchel J. Keil, Chair
Dr. Azim Houshyar
Dr. Steven Butt
Dr. Tarun Gupta
Dr. Damon Miller

Date: Wednesday, March 10, 2010 3:00 p.m. - 5:00 p.m.
College of Engineering and Applied Sciences, Room C-258

Abstract:
This research seeks to increase the understanding of the effect of non linear torsional stiffness in addition to the bending stiffness on the brake hose shape. A simulation model to predict the hose shape when it is twisted through different angles using beams and torsion springs has been presented. This would help to define the envelope that a hose is going to occupy during the movement of an automobile’s suspension. The knowledge would be useful in preventing the abrasion of the hose with nearby structures and, therefore, eliminate a significant source of failure. A fixture was fabricated in order to hold the hoses of different lengths firmly after invoking a specific twist at one end. A digitizer was used to obtain point cloud data of hose shapes between coplanar and non coplanar attachment points for different lengths of hoses. This non-contact means of taking measurement was essential in eliminating the errors in data collection. It was noted that the hose shapes were not consistent for the same angle of twist for a given length of hose from an initial no twist position. The torque value for angular deformations was adjusted in order to define the torsional stiffness curve for all springs so that the hose shape would lie near the center of the scans for every 100 twist from 00-1800 for 11in, 13in and 16in brake hoses held between coplanar attachment points. A neural network model with three hidden layers consisting of three neurons in each layer was used to approximate the torsional stiffness curves. The torsional stiffness curve that predicted the hose shape between non coplanar attachment points was different from that for coplanar points. It was found that the axial force in the beams for the two configurations had significantly different characteristics. The interaction of the axial forces with the angular deformation of the torsion springs for different lengths of hoses and its resulting effect on predicting hose shape has been presented.