Theory for the Plasticity of Glassy Polymers

Robertson, Richard E.

doi:10.1063/1.1726558

Cited by 361 publications

(171 citation statements)

References 29 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…Remark 3: There are many models for the rate and temperature-dependent yield strength of polymers in the literature which consider plastic flow as a thermally-activated process (e.g., Eyring, 1936;Robertson, 1966;Argon, 1973). Most of these models give a reasonably acceptable representation of the variation of the yield strength with temperature and strain rate, but over limited ranges of these variables.…”

Section: Wherementioning

confidence: 99%

A thermo-mechanically-coupled large-deformation theory for amorphous polymers in a temperature range which spans their glass transition

Srivastava

Chester

Ames

et al. 2010

International Journal of Plasticity

207

View full text Add to dashboard Cite

Amorphous thermoplastic polymers are important engineering materials; however, their nonlinear, strongly temperature-and rate-dependent elastic-viscoplastic behavior is still not very well understood, and is modeled by existing constitutive theories with varying degrees of success. There is no generally agreed upon theory to model the large-deformation, thermo-mechanically-coupled, elastic-viscoplastic response of these materials in a temperature range which spans their glass transition temperature. Such a theory is crucial for the development of a numerical capability for the simulation and design of important polymer processing operations, and also for predicting the relationship between processing methods and the subsequent mechanical properties of polymeric products. In this paper we extend our recently published theory , IJP 25, 1474-1494Ames et al., 2009, IJP 25, 1495-1539 to fill this need.We have conducted large strain compression experiments on three representative amorphous polymeric materials -a cyclo-olefin polymer (Zeonex-690R), polycarbonate (PC), and poly(methyl methacrylate) (PMMA) -in a temperature range from room temperature to approximately 50C above the glass transition temperature, ϑ g , of each material, in a strain-rate range of ≈ 10 −4 to 10 −1 s −1 , and compressive true strains exceeding 100%. We have specialized our constitutive theory to capture the major features of the thermomechanical response of the three materials studied experimentally.We have numerically implemented our thermo-mechanically-coupled constitutive theory by writing a usermaterial subroutine for a widely-used finite element program. In order to validate the predictive capabilities of our theory and its numerical implementation, we have performed the following validation experiments: (i) a plane-strain forging of PC at a temperature below ϑ g , and another at a temperature above ϑ g ; (ii) blowforming of thin-walled semi-spherical shapes of PC above ϑ g ; and (iii) microscale hot-embossing of channels in Zeonex and PMMA above ϑ g . By comparing the results from this suite of validation experiments of some key features, such as the experimentally-measured deformed shapes and the load-displacement curves, against corresponding results from numerical simulations, we show that our theory is capable of reasonably accurately reproducing the experimental results obtained in the validation experiments.

show abstract

Section: Wherementioning

confidence: 99%

A thermo-mechanically-coupled large-deformation theory for amorphous polymers in a temperature range which spans their glass transition

Srivastava

Chester

Ames

et al. 2010

International Journal of Plasticity

207

View full text Add to dashboard Cite

show abstract

“…2(b). Numerous theories have been developed in the literature [13][14][15][16] in order to model the strain rate and temperature dependence of the yield stress of amorphous polymers over a wide range of strain rate and temperature. However, few models allow reproducing the yield stress of polymers in their glass transition or rubbery regions.…”

Section: Yield Stress Modellingmentioning

confidence: 99%

Impact behaviour of an innovative plasticized poly(vinyl chloride) for the automotive industry

Bernard

Bahlouli

Wagner-Kocher

et al. 2015

EPJ Web of Conferences

View full text Add to dashboard Cite

Abstract. Plasticized poly(vinyl chloride) (PPVC) is widely used in the automotive industry in the design of structural parts for crashworthiness applications. Thus, it is necessary to study and understand the influence of the mechanical response and mechanical properties of PPVC over a wide range of strain rate, from quasi-static to dynamic loadings. The process is also investigated using different sample thicknesses. In this work, the strain rate effect of a new PPVC is investigated over a wide range of strain rates at three temperatures and for three thicknesses. A modelling of the yield stress is also proposed. The numerical prediction is in good agreement with the experimental results.

show abstract

“…Near a glass transition where a temperature increase produces important structural alterations that increase the fraction of liquid-like material (see Section 11.4.3), different considerations are necessary to change the emphasis from inter-molecular to intra-molecular resistances to deformation. This was achieved by Robertson (1966Robertson ( , 1968) in a theoretical model in which thermal equilibrium concentrations of strain producing "flexed" molecular conformation under the applied shear stress are calculated from Boltzmann statistics through which a structural reference temperature 0 (above Tg) is defined that in turn defines the effective deformation resistance through the free volume model of the glass transition of Williams, Landel and Ferry (1955). Argon and Bessonov (1977a) have compared 'he Robertson model to theirs and have concluded that it should be the model of choice ne-r T,.…”

Section: (-)G = a -B(t/js)mentioning

confidence: 99%

Inelastic Deformation and Fracture of Glassy Solids

Argon¹

1991

View full text Add to dashboard Cite

Theory for the Plasticity of Glassy Polymers

Cited by 361 publications

References 29 publications

A thermo-mechanically-coupled large-deformation theory for amorphous polymers in a temperature range which spans their glass transition

A thermo-mechanically-coupled large-deformation theory for amorphous polymers in a temperature range which spans their glass transition

Impact behaviour of an innovative plasticized poly(vinyl chloride) for the automotive industry

Inelastic Deformation and Fracture of Glassy Solids

Contact Info

Product

Resources

About