An Inverse Identification Procedure for the Evaluation of Equivalent Loading Conditions for Simplified Numerical Models in Abaqus

Round 1

Reviewer 1 Report

The authors presented an interesting inverse technique to evaluate the equivalent loading condition in ABAQUS/Explicit. The paper is well presented but needs some improvement:

1. The authors indicated that "The full models were replaced with simplified models, where some non-essential parts were removed and the boundary conditions were modified". It is not clear how the effect in changing the BCs on the overall response is accounted for?

2. The authors may need to cite and compare with the work of Voyiadjis and Abed in the area of dynamic localizations using ABAQUS/Explicit (e.g., https://doi.org/10.1115/1.4030804AND https://doi.org/10.1061/(ASCE)EM.1943-7889.0001862 )

3. Similar modeling to that presented in Figures 11 and 18 was conducted by other authors (eg., 10.1615/IntJMultCompEng.v5.i3-4.120). Any comparison?

Author Response

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Comments and Suggestions for Authors
The authors presented an interesting inverse technique to evaluate the equivalent loading condition in ABAQUS/Explicit. The paper is well presented but needs some improvement:

1. The authors indicated that "The full models were replaced with simplified models, where some non-essential parts were removed and the boundary conditions were modified". It is not clear how the effect in changing the BCs on the overall response is accounted for?

The differences between the two types of models mainly concern the deletion of certain parts of the assembly (rear mass in particular), which makes it possible to reduce the number of elements of the model, and the installation of an encastred boundary condition in place of the mass of the rear zone. This leads to the reconsideration of the impact velocity and thus to the identification of a new impact velocity and of an analytical calculation law of this impact velocity to take into account the modification of the boundary conditions of the simplified model.

2. The authors may need to cite and compare with the work of Voyiadjis and Abed in the area of dynamic localizations using ABAQUS/Explicit (e.g., https://doi.org/10.1115/1.4030804AND https://doi.org/10.1061/(ASCE)EM.1943-7889.0001862 )

This article does not deal with the notions related to the material behavior law and the notions of shear bands present in the cited articles. I therefore do not see the relevance of citing these references, insofar as the present article deals with the boundary conditions of the numerical models and the post-processing of the computational results and not with the flow law of the material.  The material flow law used in the present simulation is the Johnson-Cook one and therefore the results cannot be compared with those of the above references. Material is also not the same (brass vs. steel).

3. Similar modeling to that presented in Figures 11 and 18 was conducted by other authors (eg., 10.1615/IntJMultCompEng.v5.i3-4.120). Any comparison?

Concerning this article, which presents, among other things, numerical simulations of a dynamic shear test using a hat specimen (which brings it closer to figure 18), the dimensions of the specimens are not exactly the same, event if the cited paper presents 3 different approaches. The flow law is also not the same. The boundary conditions are not exactly comparable, whereas in the present study, the impact of a deformable projectile is actually taken into account in the numerical simulation, as well as the additional rear mass in the impact device. Again this paper focuses on the notion of geometrical simplification of numerical models and the adaptation of boundary conditions with respect to these simplifications.

Reviewer 2 Report

The authors present an inverse identification procedure for evaluating equivalent loading conditions for simplified numerical models using the  Abaqus Explicit finite element code. The introduction, presents enough relevant literature sources and the procedure proposed by the authors is well displayed.

The various examples are presented in a good and understandable manner.

The accompanied figures are clear and enable the reader to understand their content.

To sum-up, a good manuscript, worth to be published.

Author Response

Thank's a lot for your review.