Citation
Pence, Thomas James (1983) The emergence and propagation of a phase boundary in an elastic bar. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd09052006154543
Abstract
This dissertation is concerned with the dynamical analysis of an elastic bar whose stressstrain relation is not monotonic. Sufficiently large applied loads then require the strain to jump from one ascending branch of the stressstrain curve to another such branch. For a special class of these materials, a nonlinear initialboundary value problem in onedimensional elasticity is considered for a semiinfinite bar whose end is subjected to either a monotonically increasing prescribed traction or a monotonically increasing prescribed displacement. If the stress at the end of the bar exceeds the value of the stress at any local maximum of the stressstrain curve a strain discontinuity or "phase boundary" emerges at the end of the bar and subsequently propagates into the interior. For classically smooth solutions away from the phase boundary, the problem is reducible to a pair of differentialdelay equations for two unknown functions of a single variable. The first of these two functions gives the location of the phase boundary, while the second characterizes the dynamical fields in the highstrain phase of the material. In these equations the former function occurs in the argument of the latter, so that the delays in the functional equations are unknown. A shorttime analysis of this system provides an asymptotic description of the emergence and initial propagation of the phase boundary. For largetimes, a different analysis indicates that the phase boundary velocity approaches a constant which depends on material properties and on the ultimate level reached by the applied load as well. Higher order corrections depend on the detailed way in which the load is applied. Estimates for the various dynamical field quantities are given and a priori conditions are deduced which determine whether the phase boundary eventually becomes the leading disturbance.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Subject Keywords:  Hyperelasticity; Phase boundary propagation; Phase transformation 
Degree Grantor:  California Institute of Technology 
Division:  Engineering and Applied Science 
Major Option:  Applied Mechanics 
Thesis Availability:  Public (worldwide access) 
Research Advisor(s): 

Thesis Committee: 

Defense Date:  1 October 1982 
Author Email:  pence (AT) egr.msu.edu 
Record Number:  CaltechETD:etd09052006154543 
Persistent URL:  http://resolver.caltech.edu/CaltechETD:etd09052006154543 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  3336 
Collection:  CaltechTHESIS 
Deposited By:  Imported from ETDdb 
Deposited On:  18 Sep 2006 
Last Modified:  26 Dec 2012 02:59 
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