1 ABSTRACT ____ An experimental study was undertaken to establish the viscoelastic behavior of IM7/K3B composite in compression at elevated temperature. Creep compliance, strain recovery and the effects of physical aging on the time dependent response was measured for uniaxial loading at several isothermal conditions below the glass transition temperature (T g). The IM7/K3B composite is a graph...

The present work reports a discrete stress-dependent, complex compliance spectra method that may be used to predict the mechanical response of nonlinear viscoelastic polymers during creep and recovery processes. The method is based on the observation that the real and imaginary parts of a discrete complex compliance frequency spectra obtained from creep and recovery measurements are smooth, eas...

If the shape memory alloy is subjected to the subloop loading under the stress-controlled condition, creep and creep recovery can appear based on the martensitic transformation. In the design of shape memory alloy elements, these deformation properties are important since the deflection of shape memory alloy elements can change under constant stress. The conditions for the progress of the marte...

The creep and recovery of 5% carboxyl-terminated butadiene acrylonitrile (CTBN) modified epoxy shape memory polymers (SMP) was studied. The results were compared with those for the unmodified epoxy SMP. The glass transition temperatures (Tg) were determined using Advanced Rheometric Expansion System (ARES). The creep behavior of the unmodified epoxy and 5wt.% CTBN modified epoxy SMP were studie...

In this article, experimental results on the effect of CO2 sorption and desorption on the creep response of polycarbonate (PC) are presented. Tensile specimens machined from PC sheets were exposed to CO2 and the absorbed gas mass fraction ranged from 0.045 to 0.12. The creep/creep recovery response of as-received PC, saturated PC, and saturation-cycled PC was characterized. It was found that th...

Creep deformation in < 001 > oriented single crystals of CMSX-3 has been studied at temperatures around 850°C at a stress level of 552 MPa. Detailed observations of the evolution of the dislocation structure during creep have been made. TEM stereo pairs show creep deformation in the matrix phase, leaving the 7’ precipitates undeformed. In previously undeformed crystals there is a brief incubati...

BACKGROUND Several physiological and pathological conditions in daily life cause sustained static bending or torsion loads on the spine resulting in creep of spinal segments. The objective of this study was to determine the effects of creep and recovery on the range of motion, neutral zone, and neutral zone stiffness of thoracolumbar multi-level spinal segments in flexion, extension, lateral be...

PURPOSE In juvenile tree shrews, positioning a negative-power lens in front of an eye produces a hyperopic shift in refractive state and causes a compensatory increase in axial length over several days so that the eye is myopic when the lens is removed. During negative lens compensation, the scleral extracellular matrix is remodeled. A biomechanical property of the sclera, creep rate, increases...

We present a constitutive model capturing some of the experimentally observed features of soft biological tissues: nonlinear viscoelasticity, nonlinear elastic anisotropy, and nonlinear viscous anisotropy. For this model we derive the equation governing rectilinear shear motion in the plane of the fiber reinforcement; it is a nonlinear partial differential equation for the shear strain. Special...