A method utilizing expansion of a diaphragm-type film specimen was developed to study in vitro biodegradation of poly(etherurethane urea) (PEUU) under conditions of dynamic loading (fatigue). A finite element model was used to describe the strain state, which ranged from uniaxial at the edges of the film to balanced biaxial tensile strain at the center. During testing, the film was exposed to a...

In the current study the nonlinear viscoelastic response of a polymer matrix composite under multiple creep/creep-recovery loading is presented. The influence of creep/creep-recovery multiple step loading in the overall strain response both viscoelastic and viscoplastic is examined and an attempt for modeling this behaviour is attempted. An increase in the parameters of nonlinearity is observed...

This chapter constitutes an introduction to creep and to the creep response of Aluminium and its alloys. Its major goals are: to provide basic information on creep and its mechanisms to give a description of the more extensively used mathematical relations among creep variables (time, stress and temperature) to illustrate the creep response of pure Aluminium and of Al-Mg alloys to provide a syn...

In this study, a large number of creep tests were carried out to study the effect of stress level and testing temperature on the creep behavior of 63 Sn/37Pb solder in a systematic manner. Based on the dislocation controlled creep mechanism and Gibbs’ free-energy theory, a new creep constitutive model was proposed. The model was found to describe accurately the creep flow of the solder and to b...

From decades Creep has been known and studied for textile materials. In comparison, a newly observed phenomenon of inverse creep seems not to have received much attention. A new instrument has been fabricated to measure creep and inverse creep in textile materials particularly yarns. Creep and Inverse creep measurements of few of the textile yarns like nylon multifilament yarn, Polyester multif...

An instrument for measuring the creep response of a material maintained under a controlled environment of temperature and vapor pressure is described. The temperature range of the instrument is 20-250 degrees C while the range of vapor pressure is 0-1 atm. Data are presented for tests conducted on this instrument with Nafion, a perfluorinated ionomer developed by DuPont and used as a membrane i...

Creep deformation and rupture experiments are conducted on samples of the Ni-base superalloy directionally solidified GTD-111 tested at temperatures between 649°C and 982°C and two orientations (longitudinally and transversely oriented). The secondary creep constants are analytically determined from creep deformation experiments. The classical Kachanov–Rabotnov model for tertiary creep damage i...

This paper characterized bovine extraocular muscles (EOMs) using creep, which represents long-term stretching induced by a constant force. After preliminary optimization of testing conditions, 20 fresh EOM samples were subjected to four different loading rates of 1.67, 3.33, 8.33, and 16.67%/s, after which creep was observed for 1,500 s. A published quasilinear viscoelastic (QLV) relaxation fun...

The creep behavior of bagasse-based composites with virgin and recycled polyvinyl chloride (B/PVC) and high density polyethylene (B/HDPE) as well as a commercial wood and HDPE composite decking material was investigated. The instantaneous deformation and creep rate of all composites at the same loading level increased at higher temperatures. At a constant load level, B/PVC composites had better...