Deformation of thermosetting resins at impact rates of strain. Part 2: constitutive model with rejuvenation

Processing-induced Properties in Glassy Polymers

“…Buckley and Jones 14 already proposed in their paper on the constitutive modeling of amorphous polymers to use the fictive temperature to describe the structural state of the material. In a later publication, 15 Buckley also added the notion that there should be an evolution contributed to the fictive temperature. The use of the fictive temperature by Buckley in this sense is the same as the use of the state parameter S a 19 to describe the thermomechanical history of the material as done here.…”

“…[4][5][6][7][8][9] These plastic instabilities are the same as those found for short-term failure, observed in tensile testing under constant strain rate. 10 In the last 15 years, a lot of effort has been invested by a number of groups at different universities into the development and validation of 3D constitutive models that can describe this localization behavior of glassy polymers, for example, in the group of Mary Boyce at MIT, [11][12][13] the group of Paul Buckley in Oxford [14][15][16] and in our Eindhoven group. [17][18][19] It was shown in subsequent quantitative studies 10,[19][20][21][22][23][24] that it is the large strain intrinsic behavior (yield, strain softening, and subsequent strain hardening) of the polymer that determines the macroscopic localization behavior, and thus failure.…”

Micromechanical modelling of reversible and irreversible thermo-mechanical deformation of oriented polyethylene terephthalate

“…Crystal plasticity [19] is used as a constitutive model for the crystalline phase, with viscous slip on the (limited number of) slip systems. The non-crystalline phase can be modelled with one of the material models suitable for glassy polymers, such as the model by Buckley et al [20,21], by Boyce et al [22,23] and by Govaert et al [24,25]. In this article, the model by Govaert et al, referred to as the EGP model, is used.…”

Two-subsystem thermodynamics for the mechanics of aging amorphous solids

“…The formal description of aging dynamics often is based on a concept of internal state variables [3], particularly in the form of configurational temperature, first proposed by Tool [9], and then used intensively, e.g., in [10][11][12][13][14][15][16]. According to this concept, the amorphous solid is described by two, rather than one, thermal degrees of freedom, namely a kinetic one and a configurational one.…”

“…While the kinetic (vibrational) degree of freedom accounts for intra-basin thermodynamics, the configurational one describes the inter-basin thermodynamics [17][18][19][20][21][22][23][24]. Models have been developed for the evolution of the kinetic and configurational thermal degrees of freedom [10][11][12][13][14][15], as well as constitutive expressions have been formulated for a stress tensor and for a plastic flow rule for the mechanical deformation of aging solids. However, in these models the mutual interaction of the kinetic and configurational subsystems is in general incomplete, as discussed in the sequel of this paper, and leaves room for further investigation and generalization.…”