We have assessed viscoelastic properties of pericardium within the physiological range of stresses and related mechanical behavior to fiber direction as defined by scanning electron microscopy. Stiffness, stress relaxation, and creep were measured in samples taken from the anterior surface of 14 canine pericardia. Stress-strain relations generally were not exponential; stiffness at a stress of ...

Ligaments, tendons and other soft tissues are nonlinearly viscoelastic. To discriminate among various constitutive equations which may be used to describe the tissue, appropriate experimental modalities are requisite. Ideally, testing should span physiologic ranges for load (or strain), load history (recovery and reloading), and load onset and duration, and a robust model will fit all data. Met...

The effect of strain rate on the inelastic properties of nanocrystalline Au films was quantified with 0.85 and 1.76 lm free-standing microscale tension specimens tested over eight decades of strain rate, between 6 10 6 and 20 s . The elastic modulus was independent of the strain rate, 66 ± 4.5 GPa, but the inelastic mechanical response was clearly rate sensitive. The yield strength and the ulti...

Under long-term loading creep conditions, mineralized biological tissues like bone are expected to behave in a similar manner to synthetic composites where the creeping matrix sheds load to the elastic reinforcement as creep deformation progresses. To study this mechanism in biological composites, creep experiments were performed at 37 °C on bovine compact bone and dentin. Static compressive st...

Strain rate dependent deformation behaviours of selective laser melted Alloy 718 (IN718) are systematically studied at 550 and 650 °C by slow strain testing, with a forged counterpart as reference. Selective IN718 shows significant susceptibility to intergranular cavitation, resulting in ductility degradation decreasing rate. Detailed fractography cross section inspections employed identify the...

In two-phase TiAl-based alloys, the coexisting 2 and phases exhibit a thermal expansion mismatch, so that increased creep rates during thermal cycling may be expected. Creep deformation of two g-TiAl-based alloys was investigated during thermal cycles between 900 and 300 or 350 C with applied tensile stresses of 32.5 or 37.0 MPa. Measured thermal cycling creep rates were compared with isotherma...

The creep phenomenon is considered as one of the most important deformation mechanisms under working conditions. The present study has examined the microstructure and creep properties of Sn-9.0Zn-0.5Al solder alloy after adding a small amount of Antimony (Sb). Nominal compositions of Sb additions were chosen to be 0, 0.5, 1.0, and 1.5 wt.%. The minimum strain rate was reduced for the Sb contain...

Recent studies of excessive multidecade deflections of prestressed segmentally erected box girders revealed that more accurate predictions of the prestress loss due to steel relaxation are needed for the design of large-span creep-sensitive structures. In particular, the loss needs to be calculated as part of creep structural analysis, during which the strain of concrete to which the prestressi...

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...