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Tensile Behavior (tensile + behavior)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Effects of temperature and strain rate on the tensile behavior of short fiber reinforced polyamide-6

POLYMER COMPOSITES, Issue 5 2002
Zhen Wang
Tensile behavior of extruded short E-glass fiber reinforced polyamide-6 composite sheet has been determined at different temperatures (21.5°C, 50°C, 75°C, 100°C) and different strain rates (0.05/min, 0.5/min, 5/min). Experimental results show that this composite is a strain rate and temperature dependent material. Both elastic modulus and tensile strength of the composite increased with strain rate and decreased with temperature. Experimental results also show that strain rate sensitivity and temperature sensitivity of this composite change at a temperature between 25°C and 50°C as a result of the glass transition of the polyamide-6 matrix. Based on the experimental stress-strain curves, a two-parameter strain rate and temperature dependent constitutive model has been established to describe the tensile behavior of short fiber reinforced polyamide-6 composite. The parameters in this model are a stress exponent n and a stress coefficient ,*. It is shown that the stress exponent n, which controls the strain rate strengthening effect and the strain hardening effect of the composite, is not only strain rate independent but also temperature independent. The stress exponent ,*, on the other hand, varies with both strain rate and temperature. [source]

The role of a novel p -phenylen-bis-maleamic acid grafted atactic polypropylene interfacial modifier in polypropylene/mica composites as evidenced by tensile properties

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009
J. M. García-Martínez
Abstract Present work is devoted to the study of the tensile behavior of polypropylene (PP)/mica composites with improved interfacial interactions from the matrix side caused by the presence of a p -phenylen-bis-maleamic acid grafted atactic polypropylene (aPP- pPBM) as an interfacial agent. Hence, aPP- pPBM was previously obtained, in our laboratories, by reactive processing in the melt of a by-product (atactic PP) from industrial polymerization reactors. Present article is two-fold, on one hand it has been planned to evidence the so called interfacial effects caused by this novel interfacial agent (aPP- pPBM) yielding better final properties of the heterogeneous system as a whole as revealed by tensile mechanical properties, and on the other to obtain models to forecast the overall behavior of the system. For such purpose, a Box-Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables was used to obtain polynomials to forecast the behavior of the PP/Mica system in the experimental space scanned. The existence of a critical amount of aPP- pPBM to optimize mechanical properties appears to emerge. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Thirty-year durability of a 20-mil PVC geomembrane

JOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 4 2004
E. J. Newman
In 1971, twenty circular aquaculture ponds were constructed for the W. K. Kellogg Biological Research Station in Hickory Corners, Michigan. The 30.5-m-diameter research ponds were lined using a 0.51-mm-thick fish-grade PVC geomembrane. Over the years the ponds became congested with dense, persistent stands of cattails, trees, and other vegetation, which required the ponds to be cleared and relined in September 2000 in order to allow the initiation of new experiments. The lack of holes in the exhumed geomembrane suggests that it resisted biological attack from microorganisms and also root penetration. Laboratory testing shows that the tensile behavior of the nearly 30-year-old PVC geomembrane is within current specifications for new 0.51-mm-thick PVC geomembranes. Test results also indicate that performing laboratory tests at in-situ moisture conditions provides a better estimate of the field properties of PVC geomembranes than desiccating the material prior to testing, as is required by ASTM Standard Test Methods. J. Vinyl Addit. Technol. 10:168,173, 2004. © 2004 Society of Plastics Engineers. [source]

Lateral compaction effects in braided structures

POLYMER COMPOSITES, Issue 2 2003
Robert A. Dasilva
This paper addresses the phenomenology of strand interaction in biaxial non-embedded braided textile structures under uniaxial tension. The specific interest in the development of new braided textile structures is a result of the shortcomings of current rope, belt, and cable performance under large strain controlled conditions. However, this work also holds particular significance in the area of textile composite preforms. In composites forming, the lateral strand compaction mechanism, which drives braid behavior under tension, may be applied to woven fabrics for predicting wrinkling during forming processes. Additionally, manufacturing models produced in this study may be used to predict shape and size limitations of braided composite preforms. In this paper, a generalized model is developed for these structures with the intent of characterizing and predicting mechanical behavior. The methodology consists of a modular framework, which includes the prediction of manufacturing parameters. Lateral strand compaction tests were performed to generate constitutive material curves for use in analytical geometric models. Model predictions correlate well with data generated from braid uniaxial tension tests. Results suggest that lateral strand strain drives braid tensile behavior. [source]

Effects of temperature and strain rate on the tensile behavior of short fiber reinforced polyamide-6

Constitutive modeling for intercalated PMMA/clay nanocomposite foams

POLYMER ENGINEERING & SCIENCE, Issue 12 2006
Choonghee Jo
A constitutive model for tensile behavior of PMMA/clay nanocomposite foams was developed in this study. The elastic modulus of the nanocomposites is affected by the form of clays embedded in the polymer matrix. The reinforcing effect by intercalation of the clays and the detrimental effect by clay agglomeration were considered for the determination of the elastic modulus of the nanocomposites. A viscoelastic model was adapted for the tensile behavior of the material. The developed constitutive equation is expressed in terms of clay morphology and material properties. The aspect ratio of clays and the expansion of clay layer spacing in the intercalated clay clusters were proved to play a vital role in the reinforcing mechanism. For the verification of the constitutive model, Poly(methyl-methacrylate) (PMMA)/clay nanocomposite foams were manufactured by batch process method and their uniaxial tensile test results were compared with theoretical predictions. Compared with the experimental results, the proposed constitutive equation showed agreement with the experimental test results. POLYM. ENG. SCI. 46:1787,1796, 2006. © 2006 Society of Plastics Engineers. [source]

Effects of temperature and strain rate on the tensile behavior of unfilled and talc-filled polypropylene.

POLYMER ENGINEERING & SCIENCE, Issue 12 2002
Part I: Experiments
The tensile behavior of unfilled and 40 w% talc-filled polypropylene has been determined at four different temperatures (21.5, 50, 75 and 100°C) and three different strain rates (0.05, 0.5 and 5 min,1). Experimental results showed that both unfilled and talc-filled polypropylenes were sensitive to strain rate and temperature. Stressstrain curves of both materials were nonlinear even at relatively low strains. The addition of talc to polypropylene increased the elastic modulus, but the yield strength and yield strain were reduced. The temperature and strain rate sensitivities of these materials were also different. An energy-activated, rate sensitive Eyring equation was used to predict the yield strength of both materials. It is shown that both activation volume and activation of energy increased with the addition of talc in polypropylene. [source]

Effects of temperature and strain rate on the tensile behavior of unfilled and talc-filled polypropylene.

POLYMER ENGINEERING & SCIENCE, Issue 12 2002
Part II: Constitutive equation
Based on the experimental results presented in Part I of this research, a three parameter nonlinear constitutive model has been proposed to describe the strain rate and temperature dependent tensile behaviors of unfilled and talc-filled polypropylene. One of the parameters is the elastic modulus. The other two parameters in this model are a strain exponent, m, and a compliance factor, ,. Their relationships to strain rate and temperature are obtained from the experimental results. The simulated stress-strain curves from the model are in good agreement with the test data. The analysis of the model shows that the strain exponent m, which controls the strain softening (or hardening) effect of the material, is not only strain rate independent, but also temperature independent. The compliance parameter, ,, which controls the flow stress level of the material, on the other hand, varies with both strain rate as well as temperature. Results also show that the addition of talc filler in polypropylene reduces the strain exponent m, and increase the compliance parameter, ,, which reduces the flow stress level of talc-filled polypropylene to lower than that of unfilled polypropylene. [source]