S. Kwofie¹

Structural Durability & Health Monitoring, Vol.8, No.4, pp. 295-306, 2012, DOI:10.32604/sdhm.2012.008.295

Abstract Fatigue life of components may be enhanced by mechanical surface treatments, such as shot penning, which induce compressive residual stresses in the component's surface. Under cyclic/fatigue loads, however, relaxation of the residual stress may occur thus, reducing the optimum benefit of the surface treatment. For health monitoring / life prediction under such conditions it is important to be able to assess stress relaxation in real-time. However, the phenomenon of cyclic relaxation of residual stress is not well understood and its tracking during component operation is a technical challenge. By means of cyclic plastic deformation model and the Matlab/Simulink Program cyclic… More >

JA. Herzog^∗, TR. Leonard^†, A. Jinha^†, W. Herzog^†,‡

Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 1-17, 2014, DOI:10.3970/mcb.2014.011.001

Abstract Titin is the third most abundant protein in sarcomeres and fulfills a number of mechanical and signaling functions. Specifically, titin is responsible for most of the passive forces in sarcomeres and the passive visco-elastic behaviour of myofibrils and muscles. It has been suggested, based on mechanical testing of isolated titin molecules, that titin is an essentially elastic spring if Ig domain un/refolding is prevented either by working at short titin lengths, prior to any unfolding of Ig domains, or at long sarcomere (and titin) lengths when Ig domain un/refolding is effectively prevented. However, these properties of titin, and by extension… More >

Ligia Munteanu¹, Veturia Chiroiu¹

CMC-Computers, Materials & Continua, Vol.28, No.1, pp. 57-80, 2012, DOI:10.3970/cmc.2012.028.057

Abstract This paper discusses the modeling and feedforward control of hysteresis in a Cantor-like piezoelectric plate. The generalized play operator is analyzed in connection with the plate equations. Results show that hysteresis can be reduced to less than 40% when applying the feedforward control. The subject of the paper belongs to the field of dynamics, characterization and control at the micro/nanoscale. The choose of the Cantor-like piezoelectric plate is motivated by its special property to generate the subharmonic waves due to the anharmonic coupling between the extended-vibration (phonon) and the localized-mode (fracton) regimes. This behavior is a benefit for several applications… More >

Ala Tabiei¹, Suraush Khambati²

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.1, pp. 25-45, 2015, DOI:10.3970/cmes.2015.105.025

Abstract A constitutive model to describe the behavior of rubber from low to high strain rates is presented. For loading, the primary hyperelastic behavior is characterized by the six parameter Ogden’s strain-energy potential of the third order. The rate-dependence is captured by the nonlinear second order BKZ model using another five parameters, having two relaxation times. For unloading, a single parameter model has been presented to define Hysteresis or continuous damage, while Ogden’s two term model has been used to capture Mullin’s effect or discontinuous damage. Lastly, the Feng-Hallquist failure surface dictates the ultimate failure for element deletion. The proposed model… More >

Tao Cui¹, Wenhao Liao¹ and Daren Yu ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.45, No.3, pp. 273-294, 2009, DOI:10.3970/cmes.2009.045.273

Abstract Aerodynamic hysteresis is of practical importance for the flying airfoils. Motivated by the problem of global description on the hysteresis behaviors, this paper proposes a topological approach to analyze and model the hysteresis behaviors exhibited in the airfoil flow from a viewpoint of dynamic system theory. The approach is based on the topological invariant rules of singular points under topological mapping. It is able to theoretically explain such discontinuous hysteresis phenomena, and make consistent and accurate predictions of the hysteresis behaviors in the airfoil flow. The model results have shown that the present model is in good agreement with the… More >

Veturia Chiroiu¹, Ioan Ursu², Ligia Munteanu³, Tudor Sireteanu⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 91-106, 2012, DOI:10.3970/fdmp.2011.008.091

Abstract The Kadomtsev-Petviashvili (KP) equation describes the evolution of nonlinear, long waves of small amplitude with slow dependence on the transverse coordinate. The KP equation coupled with the generalized play operator is studied in this paper in order to explain the dilatonic behavior of the soliton interaction and the generation of huge waves in shallow waters. Hirota bilinear method and results from a nonlinear semigroup theory are applied to simulate the resonant soliton interactions. More >

Chein-Shan Liu^1,2

CMC-Computers, Materials & Continua, Vol.5, No.2, pp. 151-160, 2007, DOI:10.3970/cmc.2007.005.151

Abstract An accurate magnetization requires that both the reversible and irreversible components be modeled. The classical Landau-Lifshitz model deals with only the irreversible component of magnetization. We first subject the Landau-Lifshitz equation to an AC external field by performing a computation through the closed-form solution and the resulting hysteresis loop is displayed to show its deficiency. Then we modify the Landau-Lifshitz model into a new one by including a reversible part and an irreversible part accompanying with the switching criteria between these two states. With the new solutions we display the influence of parameters on the hysteresis loops of magnetic materials… More >

Tian-Zhong Wang¹, You-He Zhou^1,2

CMC-Computers, Materials & Continua, Vol.21, No.1, pp. 41-64, 2011, DOI:10.3970/cmc.2011.021.041

Abstract Based on the thermodynamic theory and the postulates of Jiles and Atherton, a general coupled magnetic-elastic-thermal free-energy model with hysteretic nonlinearity is established for Terfenol-D rods, in which the effect of Weiss molecular field is incorporated. The quantitative agreement between numerical simulation results predicted by the free-energy model and existing experimental data confirms the validity and reliability of the obtained nonlinear theoretical model, and indicates that the free-energy model can accurately capture the nonlinear hysteresis characteristic of Terfenol-D. Meanwhile, the free-energy model is employed to investigate the influences of mechanical stress and the temperature on the magnetostrictive effect of Terfenol-D… More >