Dislocation Avalanches in Compressive Creep and Shock Loadings

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript proposes a theoretical framework for dislocation-mediated plasticity and dislocation avalanches using a gradient plasticity model with thermodynamic consistency. The author attempts to explain plastic strain bursts and acoustic emissions within a continuum description, advancing earlier mean-field theories. Some comments can be found:

• Lack of clarity in the narrative and structure, making it difficult for a non-specialist to follow.

• Absence of empirical comparison or validation with experimental data.

• Figures are underexplained, and their significance is not sufficiently discussed in the text.

• The presentation lacks conciseness; derivations dominate while physical intuition and discussion are somewhat underdeveloped.

• The title can be rewritten and improved.

• The introduction is long and detailed but lacks a clear statement of novelty. Clarify: what is new in this theory compared to prior models (e.g., DDD simulations, SOC-based frameworks)?

• Abstarct can be improved

• Break the long background into two parts: (a) dislocation avalanches in experiments and simulations; (b) limitations in current modeling that motivate this work.

• Add a final paragraph in the introduction summarizing the structure and key contributions of the paper.

• It is preferable to use the passive form instead of repetition of "WE"

• Provide a flowchart that shows how dislocation emission, plastic slip, and damage parameter interact dynamically.

• Compare your approach briefly with other gradient plasticity models (e.g., Anand, Aifantis, Fleck–Hutchinson).

• Explain why this motion is important: is it observable? Does it correspond to slip band nucleation?

• Equation (44) for velocity is quite abstract—connect it to physically meaningful quantities like strain rate, stress drop, or AE signal.

• Include a small subsection that explains the numerical method used: time stepping, spatial discretization, stability constraints.

• Discuss limitations of 1D modeling and suggest future 2D/3D implementations.

• In the conclusion, Include bullet points summarizing Key findings, What phenomena are captured well, What extensions are needed (e.g., temperature dependence, multi-axial loading).

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript "Gradient Plasticity and Dislocation Avalanche" has deals with a new approach to dislocation plasticity that allows one to describe emission events and stress spikes, and to discuss computational experiments aimed at modeling the processes of compressive creep and shock compression in samples of different compositions and sizes. The main result of the manuscript is obtaining an expression for the speed of propagation of a slip band. The main shortcoming of the manuscript is the lack of a comparison of the main results of the manuscript with experimental data. In addition, it would be desirable to discuss the possibility of applying the approach presented in the manuscript to real anisotropic polycrystalline materials with crystallographic texture. My conclusion is the manuscript "Gradient Plasticity and Dislocation Avalanche" can be published after major revisions.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript presents a theoretical study of plastic deformation mediated by dislocation motion. The author proposes a thermodynamically consistent, mean-field plasticity theory enhanced with strain-gradient plasticity to describe mesoscale phenomena such as acoustic emissions and slip-band formation. Numerical simulations are carried out to demonstrate the behavior of dislocation avalanches under both compressive creep and shock compression.

 

 

1)      The numerical scheme used for the simulations (e.g., time stepping, discretization, stability) is not described in sufficient detail. What numerical methods were used to solve the PDEs? Were any convergence or sensitivity analyses performed?

2)      The conclusion section should be improved to help a reader not familiar with thetopic.

3)      The novelty of the work should be highlighted better.

4)      The predicted statistics of DEEs could be directly compared to AE measurements in microcrystals or nanocrystalline metals, enabling refinement of the damage evolution equations and calibration of model parameters.

5)      The treatment of noise (Langevin force) is central to triggering DEEs, but the numerical handling of this stochastic term is not clearly explained. Is the noise uniformly distributed in space and time? How was the correlation scale set?

6)  Additionally, although the article is authored by a single researcher, it is recommended to avoid the use of the first-person singular pronoun ("I") in scientific writing. An impersonal style (e.g., "we find", "it is observed", or passive forms) is generally preferred to maintain objectivity and consistency with standard scientific conventions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

   The author developed a theory and conducted simulations of uniaxial loading of a single slip specimen. The author introduced a novel approach to dislocation plasticity capable of describing emission events and stress bursts, and discussed about computational experiments intended to model the processes of compressive creep and shock compression in samples of various makeup and sizes.

 

Comments :

1. What does it add to the subject area compared with other published articles and studies? Describe this matter in a conclusion section.
2. L635 : Show a value of the free energy barrier using a unit of J, K, or eV.
3. Fig. 8 (b) and Fig. 10 : Explain the reason why the results of damage, stress became like falling rain?
4. Fig. 10 : Explain the reason why the deviation of DDE was large.
5. Fig. 13 : Add inscriptions of (a)-(c) in response to the caption of the figure13.
6. Fig. 14 : There is a difference of the values of stress and strain whenever repeated.　Explain about the cause of the difference of the values of stress and strain.

 

 

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Next time, please indicate the changes in the manuscript to be easily followed by the reviewers.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript was revised almost according to my comments.

Therefore, I recommend it for publication in the present form.