Experimental and Computational Analysis of Low-Velocity Impact on Carbon-, Glass- and Mixed-Fiber Composite Plates
Round 1
Reviewer 1 Report
Dear Author,
the submitted manuscript report the mechanical response of CFRP and GFRP panels under low impact velocity experimentally and computationally.
This reviewer satisfy with the design and result of the aforementioned study.
One thing on the introduction part, please restructure the literature surveys in a course of meaningful story not by bunch of papers in series.
After that minor revision, this reviewer would suggest accept by J Compo Sci.
Author Response
Thanks for your feedback. The introduction part was revisited and modified. Please see the attachment.
Reviewer 2 Report
The author has done excellent studies in understanding different fibers in different polymers and their impact resistance. Impact resistance is critical in applications such as aerospace and automobile. Minor revision is needed for this paper.
- The author used ASTM low-velocity standards - can the author include that information briefly in the experimental section and comment on the influence of different velocity?
- During the FEM studies, can the author provide details regarding the parametric studies? is this done by the ADPL programming? Can the author list the coding in the supporting documents (suggested for the impact of this research)? How does the author control the death of element for material failure - what is the criteria?
Author Response
Thanks for your feedback. The manuscript was updated, please see the attachment.Below is the answers to your points:
The author used ASTM low-velocity standards. Can the author include that information briefly in the experimental section and comment on the influence of different velocity?
- ASTM low-velocity standard is briefly explained in section 2.2. The constant impact energy level of 20 J, which corresponds to an impact velocity of 2.06 m/s was only considered in all experiments as there is another study for changing the impact energies and their effect on the damage characterization, which is out of the scope of this study.
During the FEM studies,
- Can the author provide details regarding the parametric studies?
The Probabilistic Design System (PDS) module of commercial finite element software ANSYS was used for the Monte-Carlo simulation. A total of 1000 analysis loops are run to obtain the output parameters as a function of the set of random input variables. The 19 plates were manufactured and then tested based on previous work using the Monte Carlo method for random variables to evaluate the effect of variability in the governing parameters for the outcome of the experiment. We selected the von Mises equivalent stress as the outcome of the numerical experiment for the new proposed plates design.
- Is this done by the ADPL programming?
It was done using The Probabilistic Design System (PDS) module of commercial finite element software ANSYS.
- Can the author list the coding in the supporting documents (suggested for the impact of this research)?
It was done using The Probabilistic Design System (PDS) module of commercial finite element software ANSYS.
- How does the author control the death of element for material failure - what is the criteria?
The simulation was accomplished through a concept known as birth and death of elements in ANSYS. To achieve the “element death” effect, the ANSYS program does not actually remove “killed” elements. Instead, it deactivates them by multiplying their stiffness by a severe reduction factor (ESTIF). This factor is set to 1.0E-6 by default. An element's strain is also set to zero as soon as that element is killed. In like manner, when elements are “born”, they are not added to the model; they are reactivated. When an element is reactivated, its stiffness, mass, element loads, etc. return to their full original values.
