Mechanochemical reactions of some polyurethane elastomers. 3. Prediction of long-term uniaxial tensile creep using linear compliance as a basis

1986 ◽  
Vol 264 (7) ◽  
pp. 590-594 ◽  
Author(s):  
C. V. Oprea ◽  
A. C. Constantinescu ◽  
P. B�rsanescu
Keyword(s):  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Polyurethane Elastomers ◽  
Mechanochemical Reactions ◽  
Uniaxial Tensile Creep

Tensile Creep Behavior of HPC at Early Ages under Different Curing Temperatures

2011 ◽  
Vol 250-253 ◽  
pp. 434-439 ◽  
Author(s):  
Yang Yang ◽  
Peng Li ◽  
Yan Ping Wu
Keyword(s):  
Creep Rate ◽  
Creep Behavior ◽  
Strength Class ◽  
Concrete Specimen ◽  
Curing Temperature ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Creep Coefficient ◽  
The Difference ◽  
Uniaxial Tensile Creep

This paper presents an experimental investigation on tensile basic creep behavior of HPC at early ages by using a uniaxial tensile creep testing apparatus. Concrete specimens of 100×100×400mm with compressive strength class 60MPa was used, sealed and loaded at different curing temperature. The effects of the curing temperature and the age at loading on creep behavior are discussed. The results show that tensile specific creep and creep rate of HPC at early ages were governed by the age at loading. The specific creep, creep coefficient and creep rate were larger at earlier loading ages, and decreased exponentially with age at loading. The tensile specific creep decreased with curing temperature, but the difference in creep due to different curing temperatures decreased with the age at loading, and could be ignored while concrete specimen being loaded after the age of 7 days.

Viscoelastic Finite Element Modeling of Bimodal High Density Polyethylene (HDPE) Piping Materials for Nuclear Safety-Related Applications

2010 ◽  
Author(s):  
Do-Jun Shim ◽  
Prabhat Krishnaswamy ◽  
Yunior Hioe ◽  
Sureshkumar Kalyanam
Keyword(s):  
Finite Element ◽  
Service Life ◽  
High Density Polyethylene ◽  
Viscoelastic Behavior ◽  
Time Dependent ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Fe Model ◽  
Creep Tests ◽  
Uniaxial Tensile Creep

The U.S. Nuclear Regulatory Commission (USNRC) has recently approved Relief Requests for the use of high density polyethylene (HDPE) piping in safety-related applications. The ASME Boiler and Pressure Vessel Code, meanwhile, has developed Code Case N-755 that defines the design and service life requirements for PE piping in nuclear plants though it has not as yet been approved by the USNRC. One of the issues of concern is premature failure of PE piping due to slow crack growth (SCG) that can initiate due to a combination of sustained loads, elevated temperatures, and a pre-existing defect. Understanding and predicting the SCG behavior is an essential step in developing a methodology for predicting the service life of PE piping. The first step in studying the failure process in a polymer under a constant sustained load is the selection of a suitable constitutive model to represent the time-dependent behavior of the material. In this paper, uniaxial tensile creep tests were performed for a bimodal HDPE (PE4710) piping material. This creep data was used to determine the viscoelastic material constants for this bimodal HDPE using a power-law creep model. These material constants were used in finite element (FE) analyses to study the viscoelastic behavior of the bimodal HDPE. As a first step, the FE model was verified by comparing the results from numerical simulations and experiments for a set of uniaxial tensile creep tests. The FE model was then applied to study the viscoelastic behavior of a SCG specimen. The time dependent stress and strain fields were investigated.

Molecular mobility of poly(methyl methacrylate) glass during uniaxial tensile creep deformation

2009 ◽  
Vol 47 (17) ◽  
pp. 1713-1727 ◽  
Author(s):  
Hau-Nan Lee ◽  
Keewook Paeng ◽  
Stephen F. Swallen ◽  
M. D. Ediger ◽  
Rebecca A. Stamm ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Creep Deformation ◽  
Molecular Mobility ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Poly Methyl Methacrylate ◽  
Uniaxial Tensile Creep
Sign in / Sign up

Export Citation Format

Share Document