Bi2O3 is an excellent ceramic candidate for transformation-mismatch plasticity because of its low melting point, its allotropic nature and the rapid creep rate of its high-temperature d-phase. Transformation-mismatch plasticity, which has been reported in many polymorphic metals, alloys and composites [1], is a deformation mechanism taking place during a phase transformation: internal mismatch ...

where J(t) is the creep compliance as it depends on time t, and E(t) is the relaxation modulus. Many constitutive models have been developed to describe the nonlinear viscoelastic behavior of materials; see Schapery (1969) and Findley et al. (1976). Models described by Johnson et al. (1996) are for large deformations and Pioletti et al. (1998) take into account the strain rate. In the present s...

In this article, the time-dependent stress redistribution analysis of magneto-electro-elastic (MEE) thick-walled sphere subjected to mechanical, electrical, magnetic and uniform temperature gradient as well as moisture concentration gradient is presented. Combining constitutive equations of MEE with stress-strain relations as well as strain-displacement relations results in obtaining a differen...

OBJECTIVES To evaluate the viscoelastic properties of demineralized dentin matrix. Stress-relaxation studies were done on matrices in tension and strain elongation or creep studies were done in both tension and compression. METHODS Mid-coronal dentin disks were prepared from extracted unerupted human third molars. Disks were 0.5 mm thick for stress-relaxation or tensile creep experiments and ...

Fatigue damage from activities of daily living has been considered to be a major cause of aseptic loosening in cemented total hip arthroplasty. The cement-bone interface is one region where loosening could occur, but to date the fatigue response of the interface has not been examined. Cement-bone specimens were prepared from fresh frozen human cadaver tissue using simulated in vivo conditions. ...

Article history: Received 17 May 2013 Accepted 6 August 2013 Available online 16 August 2013 Creep was studied in Haynes 230, a material candidate for the very high temperature reactor’s intermediate heat exchanger, at 800 C and 900 C. This study focused on the differences between the behavior at the two elevated temperature, and using the microstructure, grain boundary serrations and triple ju...

The Non-Linear Strain Energy Equivalence Theory, a semi-empirical model, is utilized to predict longterm creep from short-term compressive stress-strain experiments conducted at different strain rates. Stress-strain experiments in uni-axial compression are performed at strain rates of 3 and 0.03 %/minute to predict creep behavior and stress-strain data at several strain rates for an immiscible ...

the influence of flour content and immersion time in water on the creep behavior of composites made from high density polyethylene (hdpe) waste and mdf (medium density fiberboard) flour was investigated. mixing was carried out by a twin screw extruder and the sample was manufactured by flat hot press. firstly, the modulus of elasticity and bending strength of various mdf flour-polyethylene comp...

In this study, a novel multiscale combined creep strain and creep rupture model is proposed. By comparing to experimental data it was shown that the model provides accurate creep rupture predictions for unidirectional off-axis specimens. The creep strain model provides accurate predictions within the confines of the linear elastic restrictions used in its development. This creep strain and cree...

Experimental data (Thornton et al., 1997) show that relaxation proceeds more rapidly (a greater slope on a log-log scale) than creep in ligament, a fact not explained by linear viscoelasticity. An interrelation between creep and relaxation is therefore developed for ligaments based on a single-integral nonlinear superposition model. This interrelation differs from the convolution relation obtai...