Compression Creep and Thermal Ratcheting Behavior of High Density Polyethylene (HDPE)

Abstract

Abstract:The characterization of thermal ratcheting behavior of high density polyethylene (HDPE) material coupled with compressive creep is presented. The research explores the adverse influence of thermal cycling on HDPE material properties under the effect of compressive load, number of thermal cycles, creep time period, and thermal ratcheting temperature range. The compressive creep analysis of HDPE shows that the magnitude of creep strain increases with increase in magnitude of applied load and temperature, respectively. The creep strain value increased by 7 and 28 times between least and maximum applied temperature and load conditions, respectively. The creep modulus decreases with increase in compressive load and temperature conditions. The cumulative deformation is evident in the HDPE material, causing a reduction in the thickness of the sample under thermal ratcheting. The loss of thickness increases with increase in the number of thermal cycles, while showing no sign of saturation. The thermal ratcheting strain (TRS) is influenced dominantly by the applied load condition. In addition, the TRS decreases with increase in creep time period, which is cited to the extended damage induced due creep. The results highlight the need for improved design standard with inclusion of thermal ratcheting phenomenon for HDPE structures particularly HDPE bolted flange joint.

A Mixed Iteration Method to Determine the Linear Material Parameters in the Study of Creep Behavior of the Composites

“…In these general equations, t represents all times (i.e., the total time history of composite), whereas is the time at which stress (constant for creep loading) is applied [ 29 , 30 , 31 , 32 ]. Substitution of the above equation into Equation (11) yields: …”

Nanofiltration of Aqueous Dye Solution through the Diffused Rough Pores of a Carbonaceous–Kaolinite Amalgamation Membrane

“…In the coating, the malleable acrylic-polymer phase is tightened due to polymer−particle association 21 upon drying, so that the dry coating layer achieves adequate dimensional stability before compression. On isopressing the precursor layer to 20 000 psi for a certain length of time, creep strain takes place in the polymer phase, 22 most of which is attached to kaolin particles because of its lower vol %. The rheological response of acrylic−polymer chains under load leads to chain stretching in random directions, provided adequate duration is given.…”

Structure Evolution and Hoop-Reinforcing Mechanism of Bionic-Inspired Off-Axial Glass Fiber-Reinforced High-Density Polyethylene Pipes Fabricated via Rotating Co-extrusion

“…Materials. The HDPE (PE100, trade name 4902T, with a density of 0.95 g/cm 3 and a melt flow rate of 0.23 g/10 min under the pressure of 5 kg at 190 °C) was commercially available from Yangzi Petrochemical Company Limited (China). The short-cut glass fiber (ESC13-4.5-508A, with a fiber diameter of ∼13 μm and a fiber length of ∼4.5 mm) was purchased from Jushi Group Co. (China).…”

“…Playing the role of “artery” in the lifeline of the city, high-density polyethylene (HDPE) pressure pipelines, such as water and gas pipelines, have usually been perceived as one of the important infrastructures in modern civilization owing to their outstanding long-term properties, excellent chemical resistance, and low cost. − For decades, the global population growth and increasing need for drinking water infrastructure have been expanding the demand for HDPE pipes with higher pressure resistance. Synchronously, a series of stricter standards toward higher-performance HDPE pipe resins have been incrementally established or further perfected nowadays. , Based on the continuous innovation of polymerization technology and stronger appreciation of the molecular structure modification, several generations of HDPE pipe materials have emerged including grade PE63, PE80, PE100, and PE125. , Nevertheless, these resins will inevitably face the stress distribution defect when used as pressure pipes, of which the hoop stress is twice as much as the axial stress. , This stress characteristic will bring the risk of bamboo-like splitting for conventional extruded pipes due to the axial arrangement (the extruding direction) of molecular chains.…”