Nonlinear Stability Considerations in Thermoelastic Contact

1999 ◽  
Vol 66 (1) ◽  
pp. 109-116 ◽  
Author(s):  
J. A. Pelesko
Keyword(s):  
Steady State ◽  
Perturbation Technique ◽  
Multiple Scale ◽  
Steady State Solution ◽  
Rigid Wall ◽  
Stable Steady State ◽  
Dynamic Information ◽  
Multiple Steady State ◽  
Singular Perturbation Technique ◽  
Steady State Solutions

The behavior of a one-dimensional thermoelastic rod is modeled and analyzed. The rod is held fixed and at constant temperature at one end, while at the other end it is free to separate from or make contact with a rigid wall. At this free end a pressure and gap-dependent thermal boundary condition is imposed which couples the thermal and elastic problems. Such systems have previously been shown to undergo a bifurcation from a unique linearly stable steady-state solution to multiple steady-state solutions with alternating stability. Here, the system is studied using a two-timing or multiple-scale singular perturbation technique. In this manner, the analysis is extended into the nonlinear regime and dynamic information about the history dependence and temporal evolution of the solution is obtained.

Nonlinear Stability, Thermoelastic Contact, and the Barber Condition

2000 ◽  
Vol 68 (1) ◽  
pp. 28-33 ◽  
Author(s):  
J. A. Pelesko
Keyword(s):  
Steady State ◽  
Steady State Solution ◽  
Rigid Wall ◽  
Stable Steady State ◽  
Dynamic Information ◽  
Long Time ◽  
Uniform Expansions ◽  
Short Time ◽  
Matching Techniques ◽  
Steady State Solutions

The behavior of a one-dimensional thermoelastic rod is modeled and analyzed. The rod is held fixed and at constant temperature at one end, while at the other end it is free to separate from or make contact with a rigid wall. At this free end we impose a pressure and gap-dependent thermal boundary condition. This condition, known as the Barber condition, couples the thermal and elastic problems. Such systems have previously been shown to undergo a bifurcation from a unique linearly stable steady-state solution to multiple steady-state solutions with alternating stability. Here, the system is studied using the asymptotic matching techniques of boundary layer theory to derive short-time, long-time, and uniform expansions. In this manner, the analysis is extended into the nonlinear regime and dynamic information about the history dependence and temporal evolution of the solution is obtained.

scholarly journals The response to a hot spot in a combustion problem

1981 ◽  
Vol 23 (1) ◽  
pp. 95-102 ◽  
Author(s):  
K. K. Tam ◽  
M. T. Kiang
Keyword(s):  
Steady State ◽  
Simple Model ◽  
Initial Value Problem ◽  
Initial Temperature ◽  
Hot Spot ◽  
Steady State Solution ◽  
Initial Value ◽  
Multiple Steady State ◽  
Steady State Solutions ◽  
Combustion Problem

AbstractA simple model for a problem in combustion theory has multiple steady state solutions when a parameter is in a certain range. This note deals with the initial value problem when the initial temperature takes the form of a hot spot. Estimates on the extent and temperature of the spot for the steady state solution to be super-critical are obtained.

scholarly journals STABILITY ANALYSIS OF A LOTKA–VOLTERRA TYPE PREDATOR–PREY SYSTEM INVOLVING ALLEE EFFECTS

2010 ◽  
Vol 52 (2) ◽  
pp. 139-145 ◽  
Author(s):  
HÜSEYİN MERDAN
Keyword(s):  
Steady State ◽  
Stability Analysis ◽  
Steady State Solution ◽  
Prey Population ◽  
Stable Steady State ◽  
Allee Effects ◽  
Predator Prey ◽  
Population Dynamics Model ◽  
Steady State Solutions ◽  
Model Subject

AbstractWe present a stability analysis of steady-state solutions of a continuous-time predator–prey population dynamics model subject to Allee effects on the prey population which occur at low population density. Numerical simulations show that the system subject to an Allee effect takes a much longer time to reach its stable steady-state solution. This result differs from that obtained for the discrete-time version of the same model.

An airfoil theory of bifurcating laminar separation from thin obstacles

1990 ◽  
Vol 216 ◽  
pp. 255-284 ◽  
Author(s):  
C. J. Lee ◽  
H. K. Cheng
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Steady State ◽  
Steady State Solution ◽  
Equation System ◽  
Branch Points ◽  
Laminar Separation ◽  
Kutta Condition ◽  
Numerical Studies ◽  
Steady State Solutions

Global interaction of the boundary layer separating from an obstacle with resulting open/closed wakes is studied for a thin airfoil in a steady flow. Replacing the Kutta condition of the classical theory is the breakaway criterion of the laminar triple-deck interaction (Sychev 1972; Smith 1977), which, together with the assumption of a uniform wake/eddy pressure, leads to a nonlinear equation system for the breakaway location and wake shape. The solutions depend on a Reynolds numberReand an airfoil thickness ratio or incidence τ and, in the domain$Re^{\frac{1}{16}}\tau = O(1)$considered, the separation locations are found to be far removed from the classical Brillouin–Villat point for the breakaway from a smooth shape. Bifurcations of the steady-state solution are found among examples of symmetrical and asymmetrical flows, allowing open and closed wakes, as well as symmetry breaking in an otherwise symmetrical flow. Accordingly, the influence of thickness and incidence, as well as Reynolds number is critical in the vicinity of branch points and cut-off points where steady-state solutions can/must change branches/types. The study suggests a correspondence of this bifurcation feature with the lift hysteresis and other aerodynamic anomalies observed from wind-tunnel and numerical studies in subcritical and high-subcriticalReflows.

scholarly journals Stability of the positive steady-state solutions of systems of nonlinear Volterra difference equations of population models with diffusion and infinite delay

2000 ◽  
Vol 23 (4) ◽  
pp. 261-270 ◽  
Author(s):  
B. Shi
Keyword(s):  
Steady State ◽  
Difference Equations ◽  
Infinite Delay ◽  
Steady State Solution ◽  
Population Models ◽  
Monotone Iterative ◽  
Positive Steady State ◽  
Infinite Delays ◽  
Steady State Solutions ◽  
Volterra Difference Equations

An open problem given by Kocic and Ladas in 1993 is generalized and considered. A sufficient condition is obtained for each solution to tend to the positive steady-state solution of the systems of nonlinear Volterra difference equations of population models with diffusion and infinite delays by using the method of lower and upper solutions and monotone iterative techniques.

scholarly journals ELIMINATION OF CHAOS IN MULTIMODE, INTRACAVITY-DOUBLED LASERS IN THE PRESENCE OF SPATIAL HOLE-BURNING

2001 ◽  
Vol 11 (10) ◽  
pp. 2637-2645 ◽  
Author(s):  
MONIKA E. PIETRZYK ◽  
MILTCHO B. DANAILOV
Keyword(s):  
Steady State ◽  
Steady State Solution ◽  
Hole Burning ◽  
Stable Steady State ◽  
Small Perturbations ◽  
Spatial Hole Burning ◽  
Saturation Coefficient ◽  
Amplitude Fluctuations ◽  
The Cross ◽  
State Configuration

In this paper possibilities of a stabilization of large amplitude fluctuations in an intracavity-doubled solid-state laser are studied. The modification of the cross-saturation coefficient by the effect of spatial hole-burning is taken into account. The stabilization of the laser radiation by an increase of the number of modes, as proposed in [James et al., 1990b; Magni et al., 1993], is analyzed. It is found that when the cross-saturation coefficient is modulated by the spatial hole-burning the stabilization is not always possible. We propose a new way of obtaining a stable steady-state configuration based on an increase of the strength of nonlinearity, which leads to a strong cancellation of modes, so that during the evolution all modes, but for a single one, are canceled. Such a steady-state solution is found to be stable with respect to small perturbations.

scholarly journals The Vibration reduction of a cantilever beam subjected to parametric excitation using time delay feedback

2017 ◽  
Vol 13 (2) ◽  
pp. 7186-7193
Author(s):  
Y A Amer
Keyword(s):  
Time Delay ◽  
Cantilever Beam ◽  
Parametric Excitation ◽  
Order Approximation ◽  
Perturbation Technique ◽  
Dynamical Behavior ◽  
Multiple Scale ◽  
Steady State Solution ◽  
State Feedback Control ◽  
Resonance Case

In this paper, dynamical behavior of a cantilever beam subject to parametric excitation under state feedback control with time delay is analyzed. The method of multiple scale perturbation technique is applied to obtain the solution up to the first order approximation. We obtain equations for the amplitude and phase. We studied all resonance cases numerically. Stability of the steady state solution for the selected resonance case is studied applying Rung-Kutta fourth method and frequency response equation via Matlab 7.0 and maple 16. From the results, it can be seen that the frequency and amplitude responses for the selected resonance case can be affected by the time delayed control. Effects of different parameters of the system are studied.

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