Nonlinear creep in high-density polyethylene under time-dependent stresses

1975 ◽  
Vol 9 (5) ◽  
pp. 704-709
Author(s):  
A. F. Kregers ◽  
U. K. Vilks ◽  
M. Ya. Leitane
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Time Dependent ◽  
Nonlinear Creep

scholarly journals Time‐dependent properties of graphene nanoplatelets reinforced high‐density polyethylene

2021 ◽  
pp. 50783
Author(s):  
Zainab Al‐Maqdasi ◽  
Liva Pupure ◽  
Guan Gong ◽  
Nazanin Emami ◽  
Roberts Joffe
Keyword(s):  
High Density Polyethylene ◽  
Graphene Nanoplatelets ◽  
High Density ◽  
Time Dependent

scholarly journals Time-Temperature Superposition of Time-Dependent Birefringence for High Density Polyethylene

1970 ◽  
Vol 19 (199) ◽  
pp. 350-356
Author(s):  
Yoshiharu FUKUI ◽  
Masahiro USHIROKAWA ◽  
Tadahiro ASADA ◽  
Shigeharu ONOGI ◽  
Takami SATO
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Time Dependent ◽  
Temperature Superposition ◽  
Time Temperature Superposition

Time-dependent uniaxial piezoresistive behavior of high-density polyethylene/short carbon fiber conductive composites

2004 ◽  
Vol 19 (9) ◽  
pp. 2625-2634 ◽  
Author(s):  
Q. Zheng ◽  
J.F. Zhou ◽  
Y.H. Song
Keyword(s):  
Carbon Fiber ◽  
High Density Polyethylene ◽  
Volume Fraction ◽  
High Density ◽  
Constant Stress ◽  
Time Dependent ◽  
Short Carbon Fiber ◽  
Conductive Composites ◽  
Short Carbon ◽  
Resistance Relaxation

Short carbon fiber (SCF) filled high-density polyethylene conductive composites were studied in terms of time-dependent piezoresistive behaviors. The time-dependent change of resistance under constant stress or strain was found to be the succession of the previous pressure-dependent piezoresistance. Depending on the filler volume fraction and the level of the constant stress or strain, resistance creep and resistance relaxation with different directions were observed. An empirical expression similar to the Burgers equation could be applied to fit the data for both the resistance creep and the resistance relaxation. The fitted relaxation time as a function of pressure showed that there exist two competing processes controlling the piezoresistive behavior and its time dependence. Mechanical creep and stress relaxation of the composites were also studied, and a comparison with the time-dependent resistance implied that there is a conducting percolation network attributed to the physical contacts between SCF and a mechanical network formed by the molecular entanglement or physical crosslinking of the polymer matrix and the interaction between the filler and the matrix. It is believed that the two networks dominate the electrical and the mechanical behaviors, respectively.

Linear viscoelastic modelling of profiled high density polyethylene pipe

1996 ◽  
Vol 23 (2) ◽  
pp. 395-407 ◽  
Author(s):  
Ian D. Moore ◽  
Fuping Hu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Density Polyethylene ◽  
Parallel Plate ◽  
High Density ◽  
Time Dependent ◽  
Element Analysis ◽  
Vertical Diameter ◽  
Polyethylene Pipes ◽  
Linear Viscoelastic

Rheological model parameters for a linear viscoelastic finite element analysis are developed for corrugated polyethylene pipes. Relaxation test data from parallel plate load tests on lined corrugated high density polyethylene pipes are used, for pipes deflected to 5% and 10% vertical diameter decrease. Three-dimensional time-dependent finite element analysis is then used to estimate the time-dependent response of a 610 mm diameter pipe subjected to a constant rate of vertical diameter decrease with time. Predictions are obtained for deflection rates varying over three orders of magnitude, for direct comparison with laboratory test results. Small deflection (5%) relaxation rheology leads to good predictions of measured response up to 3% vertical pipe deflection. Large deflection (10%) rheology yields reasonable predictions for pipe response between 3% and 10% vertical deflection. Levels of strain are examined in the pipe profile, and a peak local tensile strain of 0.6% is estimated for the pipe deflected to 3% vertical diameter decrease. The rheological models should permit prediction of response under parallel plate loading for other pipe profiles. These models might also be used for estimation of pipe response under other loading conditions (such as deep burial in the field).

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