Pith. sign in

REVIEW 3 major objections 5 minor 56 references

Multi-step deformation experiment and development of a model for the mechanical behavior of polymeric glasses

T0 review · 3 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

Pith's one-line read Direct mobility measurements in a four-step deformation experiment eliminate the standard mobility-based explanation of the second stress overshoot in glassy polymers.

desk verdict A decisive experiment that removes the mobility-only rescue hypothesis for the four-step overshoot, plus a clearly labeled toy model; the paper's main overreach is the word 'unambiguously,' given the unvalidated probe proxy. read the letter →

arxiv 2608.11069 v1 pith:2RYAYLW6 submitted 2026-08-11 cond-mat.soft cond-mat.mtrl-sci

classification cond-mat.softcond-mat.mtrl-sci
keywords polymericglassesnonlinearviscoelasticityfour-stepdeformationsecondstressovershootmolecularmobilityphotobleachingphysicalagingshearmodulus
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper tries to overturn the standard assumption that the nonlinear mechanical response of glassy polymers is caused by deformation-induced changes in molecular mobility. It reports four-step loading experiments on PMMA—load, partial unload, creep, reload—while simultaneously measuring probe reorientation times with the photobleaching technique. The central finding is that molecular mobility during the reload step is ordered in the intuitive way, with higher creep stress giving higher mobility, so mobility changes cannot produce the observed second stress overshoot, whose magnitude grows with creep stress. Because the whole class of mobility-based constitutive models predicts the opposite trend, the paper proposes that deformation acts instead on the shear modulus, through the fraction of efficiently packed material, and shows that a toy model based on this mechanism qualitatively reproduces the four-step experiment and known aging behavior.

What carries the argument

The central object is the efficiently packed fraction $n$, an internal variable in the range $0<n<1$ that represents the fraction of material in a high-modulus packed state. The shear modulus is $G(n)=G_1 n + G_2(1-n)$ with $G_1>G_2$, and $n$ evolves by the population balance $dn/dt = k_f(1-n) - k_b n$, where both formation rate $k_f$ and breakage rate $k_b$ are accelerated by stress but breakage is accelerated more, so the steady-state $n$ decreases under deformation. This variable, not the relaxation time, carries the structural memory: during creep after partial unloading, the formation rate is fast enough for $n$ to climb toward its undeformed steady-state value, while after full unloading $n$ stays frozen low. On reload, the distance between the current $n$ and its flow steady-state value controls the size of the stress overshoot. The paper shows that predictions are nearly identical whether the relaxation time is stress-dependent or constant, indicating that the modulus mechanism is what carries the result.

What would settle it

Superpose a small oscillatory strain on the creep step of the four-step protocol and measure the storage modulus directly: the model predicts that partial unloading should produce a measurable rise in modulus as the efficiently packed fraction recovers during creep, while full unloading should leave the modulus nearly unchanged; if the modulus stays constant while the second overshoot still grows with creep stress, the efficient-packing mechanism is falsified.

Watch

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that the measured segmental mobility during the four-step protocol cannot explain the second stress overshoot. In a PMMA glass at $T_g-24$ K, the probe reorientation time $\tau_{1/e}$ during creep rises to values ordered by creep stress (log values 3.1, 2.8, and 2.7 for creep stresses of 10.0, 17.3, and 18.5 MPa), exactly the ordering that traditional models would produce; yet the second overshoot grows with creep stress, opposite to what those models predict. The paper concludes that the postulate that nonlinear viscoelastic behavior is solely due to deformation-accelerated relaxation is eliminated, and that the structural variable controlling the overshoot must instead act on the modulus. The replacement model keeps the Maxwell stress equation but lets the shear modulus depend linearly on the efficiently packed fraction, with that fraction obeying a stress-dependent population balance, and it qualitatively describes both the four-step experiment and single-step loading.

Load-bearing premise

The whole conclusion rests on treating the photobleaching probe's reorientation time as a faithful stand-in for the segmental mobility that controls mechanical relaxation during this specific load-unload-creep-reload history; if the probe reports something else, the elimination of mobility-based models does not follow.

Editorial extensions

If this is right

  • Constitutive models in which an internal structural state affects only the relaxation time cannot qualitatively capture the four-step experiment, since they predict that the second overshoot shrinks as creep stress increases, the opposite of the measured trend.
  • Deformation-induced mobility enhancement is real but insufficient; a complete description of glassy polymer nonlinearity must include a structural effect on the modulus or some additional mechanism independent of relaxation time.
  • The efficiently packed fraction provides a single qualitative mechanism for post-yield softening, the second overshoot, and physical aging, because in the absence of deformation $n$ rises toward equilibrium and raises the modulus, producing vertical shifts in compliance curves.
  • The model unifies rejuvenation and accelerated aging: pre-yield stress lets $n$ move toward its higher steady-state value, while post-yield stress lowers the steady-state value of $n$, matching the dual behavior seen in simulations and experiments.
  • Quantitative prediction will require moving beyond the toy model to finite strain tensors, a spectrum of relaxation times, and thermodynamic constraints, but the overshoot mechanism itself is robust to the choice of relaxation-time kinetics.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the modulus mechanism is correct, one could test it directly by superposing a small oscillatory strain during the creep step and measuring the storage modulus: partial unloading should show the modulus rising as $n$ recovers, while full unloading should leave it nearly frozen.
  • The probe reorientation time may report average segmental dynamics rather than the distribution of local packing, so a natural extension is to connect the population-balance picture to spatially heterogeneous stiff and soft environments, as suggested by simulations finding a broad distribution of local elastic moduli.
  • The same population-balance logic might apply to other glass formers, such as metallic glasses or small-molecule glasses, where a four-step load-unload-creep-reload history should likewise produce a second overshoot controlled by structural state rather than by mobility alone.
  • A practical extension is that forming and conditioning protocols involving partial unloading before final deformation could be designed around package-fraction recovery during creep, giving a new variable beyond mobility-based rejuvenation rules for controlling yield response.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper reports four-step deformation experiments on a lightly crosslinked PMMA glass at Tg-24 K, performed simultaneously with photobleaching measurements of probe molecule reorientation time tau_1/e, which the authors interpret as the segmental relaxation time. In the four-step protocol (initial constant strain rate loading, unloading to a specified stress, 1500 s creep, and a second constant strain rate loading), the second stress overshoot is larger for higher creep stress, while the tau_1/e value at the end of creep is smaller (higher mobility) for higher creep stress. The authors argue that this ordering is opposite to the correlation expected from traditional mobility-based constitutive models and thus unambiguously eliminates the postulate that nonlinear behavior is solely due to deformation-accelerated relaxation. They then propose a new toy model in which the shear modulus depends on a structural variable, the fraction of efficiently packed material, with formation and breakage rates that depend on stress, and they show that this model qualitatively reproduces the four-step behavior and also offers an explanation for vertical shifting in physical aging experiments.

Significance. If the experimental finding is robust, it is significant because it directly challenges a core assumption of the dominant class of constitutive models for glassy polymers. The simultaneous optical and mechanical measurement is a strong experimental approach, and the proposed modulus-based mechanism is a novel alternative that could redirect theoretical work. The model is explicitly a toy model, which is appropriate for a communication, but the strength of the wording in the paper ('unambiguously eliminates', 'fundamental flaw') goes beyond what the current evidence supports. The paper also connects to long-standing issues of vertical shifting in physical aging and the rejuvenation/accelerated-aging debate, which adds to its significance if the proposed mechanism is supported by future work.

major comments (3)
  1. [Results] The central negative conclusion rests on the assumption that the photobleaching probe reorientation time tau_1/e faithfully and monotonically reports the segmental alpha relaxation time that controls mechanical response under the four-step load-unload-creep-reload protocol. The paper cites previous correlations (refs 6, 7, 42, 43) established for single-step, creep, and aging experiments, but it does not validate the proxy under the present non-equilibrium history, which involves unloading, 1500 s of creep at different stresses, and reloading after a stress drop. In particular, the tau_1/e values at the end of creep are averages over 200-500 s windows and may not capture the instantaneous mobility at the onset of the second constant strain rate step. Since the entire elimination argument uses the ordering of these averaged values (3.1, 2.8, 2.7), the claim that the data 'unambiguously eliminate' the mobility-only postulate is not supported without direct validation of the proxy under the exact protocol, for example by comparing probe reorientation with a mechanical measure such as stress relaxation or creep compliance on the same sample.
  2. [Results] The experiments are single runs with no error bars or replicate measurements. The reported differences in log tau_1/e among the three creep stresses (3.1, 2.8, and 2.7) are only 0.3-0.4 decades, and the differences in the magnitude of the second stress overshoot are not quantified with uncertainties. If the uncertainty in tau_1/e for this photobleaching technique is comparable to the observed spread (as is typical in such measurements), the monotonic ordering on which the conclusion rests may not be statistically significant. The authors should either provide replicate experiments and error estimates or soften the claim that the data 'unambiguously' rule out the mobility-only mechanism.
  3. [Toy Model] The new toy model is a post hoc construction with nine free parameters (G1, G2, tau0, k0, b, f, K0, c, n0) and is not quantitatively fit to the measured stress-strain curves. The paper states that the parameter choices are illustrative and that predictions are 'robust with respect to significant changes in the values of parameters', but this is demonstrated only by a single example of scaling the moduli. No quantitative criterion for 'qualitative agreement' is defined, and no comparison between the model output and the experimental curves in Figure 3 is shown. If the model is intended as evidence that a modulus-based mechanism can explain the four-step experiment, the authors should show that the main qualitative features (second overshoot increasing with creep stress, small overshoot after full unloading) persist over a explicitly defined range of parameter values, or alternatively label the model as purely suggestive and not a validated explanation.
minor comments (5)
  1. [Eq. 1] Equation (1) and several other equations in the main text appear to be typeset incorrectly in the manuscript (e.g., '1dd Gdt dtse st=-+' is garbled); please ensure all equations display properly and use consistent notation.
  2. [Figure 2] The numerical values of the model parameters cited in the caption of Figure 2 are missing; please provide the full parameter set so that the predictions can be assessed.
  3. [Table 1] The parameters in Table 1 are listed without units; please specify the units for each parameter (e.g., G1 and G2 in MPa, tau0 in s, k0 in s^-1).
  4. [Conclusions] The Conclusions state that the optical experiments 'identified a fundamental flaw in the traditional constitutive models'; this wording is stronger than the evidence presented in the paper and should be tempered to match the experimental limitations discussed in the major comments.
  5. [References] Reference 23 (Klompen et al., Macromolecules 2005) appears to be a duplicate of reference 13; please check and correct the reference list.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the central mobility measurement is an external optical dataset, and the toy model is openly a post hoc illustration rather than a fitted prediction.

full rationale

The paper's central claim is that probe reorientation times measured during the four-step experiment rule out the mobility-only explanation of the second stress overshoot. That claim rests on an external optical measurement, not on any equation that defines the overshoot in terms of the probe time. The measured ordering (log tau_1/e = 3.1, 2.8, 2.7 for creep stresses 10.0, 17.3, 18.5 MPa) is compared directly with the stress-overshoot ordering; no fitting step or definition makes one equal to the other. The identification of tau_1/e with segmental dynamics is supported by prior experimental correlations, and while those correlations are cited from the same research groups, they are external calibrations rather than assertions whose truth is assumed by construction. The failure of the traditional mobility-based models is also demonstrated with an explicit toy model (eqs 1-3) whose predicted trend is opposite to experiment; this demonstration does not depend on a self-citation for its logical force. The new toy model is explicitly labeled a toy, with parameters chosen 'for illustrative purposes' and no claim of uniqueness or first-principles derivation. Its reproduction of the four-step trend is a sufficiency demonstration, not a prediction forced by fitting to the target data. There is no exhibited reduction of a predicted quantity to an input by construction, no fitted parameter renamed as a prediction, and no load-bearing uniqueness theorem imported from the authors' prior work. The main remaining concerns, such as whether probe reorientation faithfully reports the mechanical relaxation time under this specific load-unload-creep-reload protocol, are assumption and correctness risks rather than circularity.

Assumptions & free parameters 9 free parameters · 5 assumptions · 1 invented entities

The experimental conclusion relies on the probe-mobility proxy and single-sample data; the model conclusion relies on a two-state packing postulate with no direct evidence, the stress-dependent rate forms in Eqs 8-9, and a set of illustrative parameters in Table 1. These are assumptions and free parameters rather than externally constrained inputs.

free parameters (9)
  • G1 = 10^4 (Table 1, illustrative)
    Shear modulus of efficiently packed state; controls overshoot magnitude through Eq 4.
  • G2 = 10 (Table 1, illustrative)
    Shear modulus of inefficiently packed state; sets the modulus contrast G1 > G2.
  • tau0 = 10 s (Table 1)
    Reference relaxation time in Eq 10; case-dependent and critical for the claim that modulus alone can explain the overshoot.
  • k0 = 0.01 (Table 1)
    Prefactor for formation rate of efficiently packed material in Eq 8.
  • b = 6.3 (Table 1)
    Stress-sensitivity parameter in the formation rate, Eq 8.
  • f = 0.1 (Table 1)
    Stress-shape parameter in the denominator of Eq 8.
  • K0 = 0.4 (Table 1)
    Prefactor for the stress-dependent equilibrium constant in Eq 9.
  • c = 0.1 (Table 1)
    Stress-sensitivity of the equilibrium constant in Eq 9.
  • n0 = 0.35 (initial condition, below equilibrium 0.71)
    Initial efficiently packed fraction; represents the non-equilibrium aged glass state and directly controls whether overshoot appears.
assumptions (5)
  • domain assumption Maxwell model Eq 1 is a valid point of departure for nonlinear glassy response.
    Used in both toy models; ignores multi-mode relaxation and finite strain effects, acknowledged by the authors.
  • ad hoc to paper Glass consists of efficiently and inefficiently packed environments with distinct shear moduli connected in parallel (Eq 4).
    The authors state there is no direct experimental evidence for these domains; the assumption is motivated by a simulation of broad local modulus distribution.
  • ad hoc to paper Stress accelerates both formation and breakage rates, with breakage accelerated more (Eqs 8 and 9).
    This is needed to make the steady-state packing fraction decrease with deformation and to drive the modulus change that produces the overshoot.
  • domain assumption Probe reorientation time tau_1/e measured by photobleaching reports the segmental molecular mobility relevant to mechanical relaxation.
    Underpins the interpretation of Figures 3 and 4; the paper cites prior correlations but does not independently validate this proxy in the four-step history.
  • domain assumption Contraction is identical along the two transverse directions when converting force to true stress.
    Used in the stress calculation; stated as an assumption in the measurement section without direct verification.
invented entities (1)
  • Efficiently packed fraction n
    purpose: Internal variable controlling shear modulus in the new toy model; its population balance replaces the structural variable that controls relaxation time in traditional models.
    The authors explicitly state that no experimental evidence exists for domains with different local modulus, so the two-state packing structure is a postulated model entity rather than a measured quantity.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Multi-step deformation experiment and development of a model for the mechanical behavior of polymeric glasses." pith.science (2026). https://pith.science/paper/2RYAYLW6

@misc{pith2026260811069,
  author       = {Pith},
  title        = {Pith review of: Multi-step deformation experiment and development of a model for the mechanical behavior of polymeric glasses},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/2RYAYLW6}},
  note         = {Machine review of arXiv:2608.11069}
}
read the original abstract

Traditional models for stress-strain behavior of glassy polymers are based on the assumption that the critical features of the stress-strain response can be explained by changes in the molecular mobility. The four-step deformation experiments consisting of (i) an initial constant strain rate loading, (ii) unloading to specified stress, (iii) creep under that stress and (iv) second constant strain rate loading, challenges that assumption. Specifically, existing models fail to predict the experimentally observed large second stress overshoot in case of a slight unloading. Until now there has remained a possibility that the mobility was actually lower in case of a partial rather than complete unloading, which would preserve the main assumption, if not particular details, of these specific constitutive models. By performing direct optical experiments using the photobleaching technique simultaneously with the mechanical four-step experiments it is shown that a lower molecular mobility upon partial unloading does not take place. As traditional models cannot account for these experimental results, a new model has been developed where the changes of molecular structure manifest not in the relaxation time, but in the shear modulus, which is function of an internal variable that is the fraction of the efficiently packed material. This fraction obeys a population balance equation, where the steady-state fraction is controlled by the applied stress. In the absence of deformation, the efficiently packed fraction increases, which explains the increase in the modulus in the course of physical aging below Tg. The model qualitatively describes the four-step experiment as well as single step loading experiments.

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

56 extracted references · 54 canonical work pages

  1. [1]

    B., The yield behavior of glassy polymers

    Bowden, P. B., The yield behavior of glassy polymers. In The physics of glassy polymers, Haward, R. N., Ed. Applied Science Publishers Ltd: London, 1973; pp 279-339

  2. [2]

    In The physics of glassy polymers, Haward, R

    Crist, B., Yield processes in glassy polymers. In The physics of glassy polymers, Haward, R. N.; Young, R. J., Eds. Chapman and Hall: London, 1997; pp 155-210

  3. [3]

    M.; Medvedev, G

    Caruthers, J. M.; Medvedev, G. A., Thermo-mechanical signatures of polymeric glasses. In Polymer Glasses, Roth, C. B., Ed. Taylor & Fransis Books: London, 2016; pp 107-178

  4. [4]

    H.; Wang, G.; Wang, R

    Liu, Y. H.; Wang, G.; Wang, R. J.; Zhao, D. Q.; Pan, M. X.; Wang, W. H., Super Plastic Bulk Metallic Glasses at Room Temperature. Science 2007, 315 (5817), 1385-1388

  5. [5]

    L., Deformation behavior of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass over a wide range of strain-rates and temperatures

    Lu, J.; Ravichandran, G.; Johnson, W. L., Deformation behavior of the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass over a wide range of strain-rates and temperatures. Acta Materialia 2003, 51, 3429– 3443

  6. [6]

    F.; Ediger, M

    Lee, H.-N.; Paeng, K.; Swallen, S. F.; Ediger, M. D., Direct Measurement of Molecular Mobility in Actively Deformed Polymer Glasses. Science 2009, 323, 231-234

  7. [7]

    D., Measurement of Segmental Mobility during Constant Strain Rate Deformation of a Poly(methyl methacrylate) Glass

    Bending, B.; Christison, K.; Ricci, J.; Ediger, M. D., Measurement of Segmental Mobility during Constant Strain Rate Deformation of a Poly(methyl methacrylate) Glass. Macromolecules 2014, 47 (2), 800-806

  8. [8]

    D., Linear Stress Relaxation and Probe Reorientation: Comparison of the Segmental Dynamics of Two Glassy Polymers during Physical Aging

    Ricci, J.; Bennin, T.; Xing, E.; Ediger, M. D., Linear Stress Relaxation and Probe Reorientation: Comparison of the Segmental Dynamics of Two Glassy Polymers during Physical Aging. Macromolecules 2019, 52 (21), 8177-8186

Show all 56 references
  1. [9]

    A.; Caruthers, J

    Medvedev, G. A.; Caruthers, J. M., A comparison of constitutive descriptions of the thermo- mechanical behavior of polymeric glasses. In Polymer Glasses, Roth, C. B., Ed. Taylor & Fransis Books: London, 2016; pp 451-536

  2. [10]

    Dreistadt, C.; Bonnet, A.-S.; Chevrier, P.; Lipinski, P., Experimental study of the polycarbonate behaviour during complex loadings and comparison with the Boyce, Parks and Argon model predictions. Mater. Des. 2009, 30, 3126–3140

  3. [11]

    C.; Haward, R

    Boyce, M. C.; Haward, R. N., The post-yield deformation of glassy polymers. In The physics of glassy polymers, Haward, R. N.; Young, R. J., Eds. Chapman and Hall: London, 1997; pp 213-289

  4. [12]

    B., Physical aging of epoxy networks after quenching and/or plastic cycling

    Aboulfaraj, M.; G'Sell, C.; Mangelinck, D.; McKenna, G. B., Physical aging of epoxy networks after quenching and/or plastic cycling. J. Non·Cryst. Solids 1994, 172-174, 615-621

  5. [13]

    Klompen, E. T. J.; Engels, T. A. P.; Govaert, L. E.; Mejer, H. E. H., Modeling of the Postyield Response of Glassy Polymers: Influence of Thermomechanical History. Macromolecules 2005, 38 (16), 6997-7008

  6. [14]

    Senden, D. J. A.; van Dommelen, J. A. W.; Govaert, L. E., Physical Aging and Deformation Kinetics of Polycarbonate. J. Polym. Sci. Pol. Phys. 2012, 50 (22), 1589–1596

  7. [15]

    Clarijs, C. C. W. J.; Kanters, M. J. W.; van Erp, M. J.; Engels, T. A. P.; Govaert, L. E., Predicting plasticity-controlled failure of glassy polymers: Influence of stress-accelerated progressive physical aging. J. Polym. Sci. Polym. Phys. 2019, 57 (19), 1300-1314

  8. [16]

    G.; Emri, I., Volume Change and the Nonlinearly Thermo-Viscoelastic Constitution of Polymers

    Knauss, W. G.; Emri, I., Volume Change and the Nonlinearly Thermo-Viscoelastic Constitution of Polymers. Polym. Eng. Sci. 1987, 27 (1), 86-100

  9. [17]

    Shay, R. M. J.; Caruthers, J. M., A New Nonlinear Viscoelastic Constitutive Equation for Predicting Yield in Amorphous Solid Polymers. J. Rheol. 1986, 30 (4), 781-827

  10. [18]

    P.; Dooling, P

    Buckley, C. P.; Dooling, P. J.; Harding, J.; Ruiz, C., Deformation of thermosetting resins at impact rates of strain. Part 2: constitutive model with rejuvenation. J. Mech. Phys. Solids 2004, 52 (10), 2355 – 2377

  11. [19]

    Shay, R. M. J.; Caruthers, J. M., A Predictive Model for the Effects of Thermal History on the Mechanical Behavior of Amorphous Polymers. Polym. Eng. Sci. 1990, 30 (20), 1266-1280

  12. [20]

    M.; Adolf, D

    Caruthers, J. M.; Adolf, D. B.; Chambers, R. S.; Shrikhande, P., A thermodynamically consistent, nonlinear viscoelastic approach for modeling glassy polymers. Polymer 2004, 45 (13), 4577- 4597

  13. [21]

    C.; Parks, D

    Boyce, M. C.; Parks, D. M.; Argon, A. S., Large inelastic deformation of glassy polymers. Part I: rate dependent constitutive model. Mech. Mater. 1988, 7 (1), 15-33

  14. [22]

    E.; Timmermans, P

    Govaert, L. E.; Timmermans, P. H. M.; Brekelmans, W. A. M., The influence of intrinsic strain softening on strain localisation in polycarbonate: modeling and experimental validation. J. Eng. Mater. Technol. 2000, 122 (2), 177–185

  15. [23]

    Klompen, E. T. J.; Engels, T. A. P.; Govaert, L. E.; Mejer, H. E. H., Modeling of the Postyield Response of Glassy Polymers: Influence of Thermomechanical History. Macromolecules 2005, 38, 6997- 7008

  16. [24]

    D.; Qi, H

    Nguyen, T. D.; Qi, H. J.; Castro, F.; Long, K. N., A thermoviscoelastic model for amorphous shape memory polymers: Incorporating structural and stress relaxation. J. Mech. Phys. Solids 2008, 56 (9), 2792– 2814

  17. [25]

    M.; Srivastava, V.; Chester, S

    Anand, L.; Ames, N. M.; Srivastava, V.; Chester, S. A., A thermo-mechanically coupled theory for large deformations of amorphous polymers. Part I: Formulation. Int. J. Plasticity 2009, 25 (8), 1474- 1494

  18. [26]

    L.; Ward, D

    Bouvard, J. L.; Ward, D. K.; Hossain, D.; Marin, E. B.; Bammann, D. J.; Horstemeyer, M. F., A general inelastic internal state variable model for amorphous glassy polymers. Acta Mech. 2010, 213, 71-96

  19. [27]

    A.; Caruthers, J

    Medvedev, G. A.; Caruthers, J. M., Development of a Stochastic Constitutive Model for Prediction of Post-Yield Softening in Glassy Polymers. J. Rheol. 2013, 57 (3), 949-1002

  20. [28]

    S., Theory of aging, rejuvenation, and the nonequilibrium steady state in deformed polymer glasses

    Chen, K.; Schweizer, K. S., Theory of aging, rejuvenation, and the nonequilibrium steady state in deformed polymer glasses. Phys. Rev. E 2010, 82, 041804

  21. [29]

    M.; Larson, R

    Fielding, S. M.; Larson, R. G.; Cates, M. E., Simple Model for the Deformation-Induced Relaxation of Glassy Polymers. Phys. Rev. Lett. 2012, 108, 048301

  22. [30]

    D., Thermodynamics of materials with memory

    Coleman, B. D., Thermodynamics of materials with memory. Arch. Rational Mech. Anal. 1964, 17, 1-46

  23. [31]

    D.; Noll, W., Foundations of linear viscoelsticity

    Coleman, B. D.; Noll, W., Foundations of linear viscoelsticity. Rev. Mod. Phys. 1961, 33, 239- 249

  24. [32]

    R.; Shay, R

    Lustig, S. R.; Shay, R. M. J.; Caruthers, J. M., Thermodynamic constitutive equations for materials with memory on a material time scale. J. Rheol. 1996, 40 (1), 69-106

  25. [33]

    B.; Chambers, R

    Adolf, D. B.; Chambers, R. S.; Caruthers, J. M., Extensive validation of a thermodynamically consistent, nonlinear viscoelastic model for glassy polymers. Polymer 2004, 45 (13), 4599-4621

  26. [34]

    M., On modeling the micro-indentation response of an amorphous polymer

    Anand, L.; Ames, N. M., On modeling the micro-indentation response of an amorphous polymer. Int. J. Plasticity 2006, 22 (6), 1123–1170

  27. [35]

    de Focatis, D. S. A.; Emberly, J.; Buckley, C. P., Large Deformations in Oriented Polymer Glasses: Experimental Study and a New Glass-Melt Constitutive Model. J. Polym. Sci. Pol. Phys. 2010, 48 (13), 1449–1463

  28. [36]

    van Breemen, L. C. A.; Klompen, E. T. J.; Govaert, L. E.; Meijer, H. E. H., Extending the EGP constitutivemodel for polymer glasses to multiple relaxation times. J. Mech. Phys. Solids 2011, 59, 2191- 2207

  29. [37]

    A.; Boyce, M

    Hasan, O. A.; Boyce, M. C.; Li, Z. S.; Berko, S., An Investigation of the Yield and Postyield Behavior and Corresponding Structure of Poly ( methyl methacrylate). J. Polym. Sci. Polym. Phys. 1993, 31, 185-197

  30. [38]

    A.; Boyce, M

    Hasan, O. A.; Boyce, M. C., Energy storage during inelastic deformation of glassy polymers. Polymer 1993, 34 (24), 5085-5092

  31. [39]

    M.; Srivastava, V.; Chester, S

    Ames, N. M.; Srivastava, V.; Chester, S. A.; Anand, L., A thermo-mechanically coupled theory for large deformations of amorphous polymers. Part II: Applications. International Journal of Plasticity 2009, 25, 1495–1539

  32. [40]

    D., An effective temperature theory for the nonequilibrium behavior of amorphous polymers

    Xiao, R.; Nguyen, T. D., An effective temperature theory for the nonequilibrium behavior of amorphous polymers. J. Mech. Phys. Solids 2015, 82, 62-81

  33. [41]

    Y.; Johari, G

    G'Sell, C.; El Bari, H.; Perez, J.; Cavaille, J. Y.; Johari, G. P., Effect of Plastic Deformation on the Microstructure and Properties of Amorphous Polycarbonate. Mat. Sci. Eng. A-Struct. 1989, 110, 223- 229

  34. [42]

    F.; Ediger, M

    Lee, H.-N.; Paeng, K.; Swallen, S. F.; Ediger, M. D.; Stamm, R. A.; Medvedev, G. A.; Caruthers, J. M., Molecular Mobility of Poly(methyl methacrylate) Glass During Uniaxial Tensile Creep Deformation. J. Polym. Sci. Polym. Phys. 2009, 47 (17), 1713-1727

  35. [43]

    D., Direct Comparison of Probe Reorientation and Linear Mechanical Measurements of Segmental Dynamics in Glassy Poly(methyl methacrylate)

    Ricci, J.; Bennin, T.; Ediger, M. D., Direct Comparison of Probe Reorientation and Linear Mechanical Measurements of Segmental Dynamics in Glassy Poly(methyl methacrylate). Macromolecules 2018, 51 (19), 7785-7793

  36. [44]

    F.; Ediger, M

    Lee, H.-N.; Paeng, K.; Swallen, S. F.; Ediger, M. D., Dye reorientation as a probe of stress- induced mobility in polymer glasses. J. Chem. Phys. 2008, 128, 134902

  37. [45]

    A.; de Pablo, J

    Lee, H.-N.; Riggleman, R. A.; de Pablo, J. J.; Ediger, M. D., Deformation-Induced Mobility in Polymer Glasses during Multistep Creep Experiments and Simulations. Macromolecules 2009, 42 (12), 4328-4336

  38. [46]

    Annalen der Physik 1854, 167 (1), 56-82

    Kohlrausch, R., Theorie des elektrischen Rückstandes in der Leidener Flasche. Annalen der Physik 1854, 167 (1), 56-82

  39. [47]

    C., Non-symmetrical dielectric relaxation behaviour arising from a simple empirical decay function

    Williams, G.; Watts, D. C., Non-symmetrical dielectric relaxation behaviour arising from a simple empirical decay function. Trans. Faraday Society 1970, 66, 80-85

  40. [48]

    Struik, L. C. E., Physical Aging in Amorphous Polymers and Other Materials. Elsevier: Amsterdam, 1978; p 229

  41. [49]

    B., Effect of crosslink density on physical ageing of epoxy networks

    Lee, A.; McKenna, G. B., Effect of crosslink density on physical ageing of epoxy networks. Polymer 1988, 29, 1812-1817

  42. [50]

    A.; McKenna, G

    O'Connell, P. A.; McKenna, G. B., Large Deformation Response of Polycarbonate:Time- Temperature Time-Aging Time and Time-Strain Superposition. Polym. Eng. Sci. 1997, 37 (9), 1485- 1495

  43. [51]

    B., Shear stress relaxation and physical aging study on simple glass-forming materials

    Shi, X.; Mandanici, A.; McKenna, G. B., Shear stress relaxation and physical aging study on simple glass-forming materials. J. Chem. Phys. 2005, 123, 174507

  44. [52]

    B., Mechanical rejuvenation in polymer glasses: fact or fallacy? J

    McKenna, G. B., Mechanical rejuvenation in polymer glasses: fact or fallacy? J. Phys.: Condens. Matter 2003, 15, S737–S763

  45. [53]

    J.; Osborne, M

    Lacks, D. J.; Osborne, M. J., Energy Landscape Picture of Overaging and Rejuvenation in a Sheared Glass. Phys. Rev. Lett. 2004, 93 (25), 255501

  46. [54]

    Zhou, Z.-Y.; Peng, H.-L.; Yu, H.-B., Structural origin for vibration-induced accelerated aging and rejuvenation in metallic glasses. J. Chem. Phys. 2019, 150 (20), 204507

  47. [55]

    S.; Workum, K

    Yoshimoto, K.; Jain, T. S.; Workum, K. V.; Nealey, P. F.; de Pablo, J. J., Mechanical Heterogeneities in Model Polymer Glasses at Small Length Scales. Phys. Rev. Lett. 2004, 93 (17), 175501

  48. [56]

    Multi-step deformation experiment and development of a model for the mechanical behavior of polymeric glasses

    Mainardi, F., Fractional Calculus and Waves in Linear Viscoelasticity. Imperial College Press: London, 2010. Supporting Information for “Multi-step deformation experiment and development of a model for the mechanical behavior of polymeric glasses” Grigori A Medvedev* ,1 Enran ...

Pith tools

Reviewed August 12, 2026 · model on record in the stance chip above.