Date of Award
1-1-2017
Document Type
Dissertation
Degree Name
Ph.D.
First Advisor
Yun-Bo Yi, Ph.D.
Second Advisor
Maria Calbi, Ph.D.
Third Advisor
Ali Azadani
Fourth Advisor
Mohammad Matin
Keywords
Thermomechanical stability, Clutches, Brakes, Automotive
Abstract
Finite element analyses were performed to evaluate the stability thermal buckling existing in clutch disks. The commercial software ABAQUS had been used. It was discovered that monotonically increasing thermal loads constantly result in axisymmetric buckling modes. When the maximum values of thermal loads were located at the medium radii of the models, the non-axisymmetric modes became dominant. The buckling mode and buckling temperature of the model in which the profile of thermal load varies periodically in the circumferential direction were also tentatively studied. The [achievements] described in this part of this dissertation had been published in Ref. [33].
The numerical analysis was applied to inspect the thermal buckling of an annular plate using a reduced Fourier method. The stress stiffness matrix was derived from the geometric nonlinearity in the Green strains with a predefined circumferential wave number. It was implemented to solve non-axisymmetric problems with multiple reversals in the circumferential direction. It was shown that there exists a particular wave number with which the buckling temperature reaches a minimum. The [achievements] described in this part of this dissertation had been published in Ref. [58].
Through performing finite element analyses, the coupling between thermal buckling and thermoelastic instability (TEI) was studied. The eigenmodes (i.e. nodal temperature distributions) obtained from TEI analyses were applied as the reference thermal loads. The effects of the sliding speed, the coefficient of friction, and the boundary condition had been investigated. It was concluded that TEI and thermal buckling could interact with each other in some situations. The [achievements] described in this part of this dissertation will be published in Ref. [63].
Linear and nonlinear buckling finite element analyses were performed to evaluate the thermal postbuckling of clutch metal disks. The dominant buckling modes were firstly obtained through linear buckling FEA analyses. The scaled displacement fields obtained from the linear buckling analyses were applied to the original geometries to produce the perturbed meshes. The postbuckling behaviors were then investigated through nonlinear buckling FEA analyses. The software ABAQUS was used as the fundamental numerical tool. It was discovered the temperature dependence of material properties significantly decreases the cirtical buckling. The [achievements] described in this part of this dissertation will be published in Ref. [72].
Publication Statement
Copyright is held by the author. User is responsible for all copyright compliance.
Rights Holder
Zhuo Chen
Provenance
Received from ProQuest
File Format
application/pdf
Language
en
File Size
140 p.
Recommended Citation
Chen, Zhuo, "Thermomechanical Stability of Automotive Clutches and Brakes" (2017). Electronic Theses and Dissertations. 1358.
https://digitalcommons.du.edu/etd/1358
Copyright date
2017
Discipline
Mechanical engineering