Polypropylene is one of the most common, fastest growing and versatile thermoplastics currently used to produce tanks and chemical piping systems. Even at room temperature creep is considerable for polypropylene products. The creep behavior of strains, stresses, and displacement rates is investigated in a thick-walled cylinder made of polypropylene reinforced by functionally graded (FG) multi-w...

This paper reports (1) the latest development and application of a modified hyperbolic sine law for minimum creep strain rate and stress for both low Cr and high Cr steels, and (2) the development of a creep fracture criterion based on cavity area fraction along grain boundaries for high Cr steel. This work is part of the fundamental development of creep damage constitutive equations which were...

Directionally solidified (DS) Ni-base superalloys have become a commonly used material in gas turbine components. Controlled solidification during the material manufacturing process leads to a special alignment of the grain boundaries within the material. This alignment results in different material properties dependent on the orientation of the material. When used in gas turbine applications t...

Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic ...

In this paper, ratcheting behavior of beams subjected to mechanical cyclic loads at elevated temperature, using the rate dependent Chaboche unified viscoplastic model with combined kinematic and isotropic hardening theory of plasticity, is investigated. A precise and general numerical scheme, using the incremental method of solution, is developed to obtain the cyclic inelastic creep and plastic...

Creep damage is one of the serious problems for the high temperature industries and computational approach (such as continuum damage mechanics) has been developed and used, complementary to the experimental approach, to assist safe operation. However, there are no ready creep damage constitutive equations to be used for predicting the lifetime for this type of alloy, particularly for low stress...

Compression creep tests were performed on the ternary 91.84Sn-3.33Ag-4.83Bi (wt.%, abbreviated Sn-Ag-Bi) Pb-free alloy. The test temperatures were: −25 °C, 25 °C, 75 °C, 125 °C, and 160 °C (± 0.5 °C). Four loads were used at the two lowest temperatures and five at the higher temperatures. The specimens were tested in the as-fabricated condition or after having been subjected to one of two air a...

Both the load partitioning between hydroxyapatite (HAP) and collagen during compressive creep deformation of bone and the HAP residual strain in unloaded bone have been shown in previous synchrotron X-ray diffraction studies to be affected by the X-ray irradiation dose. Here, through detailed analysis of the X-ray diffraction patterns of bovine bone, the effect of X-ray dose on (i) the rate of ...

This study has investigated the creep properties of asphaltic concrete modified with different dosages of waste polyethylene terephthalate (PET) in two different ranges of size. Uniaxial dynamic creep test at 40°C was conducted on the cylindrical specimens of the mixtures. The load was applied in two different frequencies of 0.5 and 5Hz. Creep test results showed that the accumulated strain und...

In this study, the non-linear creep behaviour of a thick-walled cylinder made of stainless steel 316 is investigated using a semi-analytical method. The thick-walled cylinder is under a uniform internal pressure and a non-axisymmetric thermal field as a function of the radial and circumferential coordinates. For the high temperature and stress levels, creep phenomena play a major role in stress...