Enhancing the Fatigue of Mechanical Systems Such as Dispensers Entrenched on Generalized Life-Stress Models and Sample Sizes
Round 1
Reviewer 1 Report
In this paper, the authors apply the parametric accelerated life testing (ALT) to identify structural imperfections and reduce fatigue related failures. It involves (1) a parametric ALT scheme, (2) fatigue design, (3) ALTs with alterations, and (4) an estimate of whether design(s) achieve the BX lifetime.
I think the paper is significant and have different merits, but i have some concerns,
1- The mathematical model related to ALT is not mentioned well in the paper.
2- Authors have used the Weibull distribution as a lifetime model which fit the life of the devices. What about estimating the paraemters of the Weibull model.
3- Can the authors make a simulation study for the parameteric acceleration model.
Author Response
Dear Sirs:
Thank you for your review of our paper. We modified it based on the comments of the reviewers.
Comment 1. The mathematical model related to ALT is not mentioned well in the paper.
Response: Because some passages are incomprehensible and misleading in the description of the model (section 2.3), the paper was rewritten in a number of sections to better improve the English. This rewrite will have made clear some of the passages that may have been incomprehensible.
We also modified the detailed explanation in the section 2.5 (Case Study) in connection with the first section and the description of the model (section 2.3). Please check it. For verifying the effectiveness of the new dispenser system in the field, we can use formulations (41) and (42) that explain assessed life, LB, and approximated failure rate, λ, of the samples in each ALT.
We also added more explanation in the introduction to stress the innovation of this investigation and bibliographies in references. And we modified some texts in the introduction.
Comment 2. Authors have used the Weibull distribution as a lifetime model which fit the life of the devices. What about estimating the parameters of the Weibull model?
Response: As you recommend, we added some descriptions in section 2.2 and section 3(results and discussion) how to estimate the parameters of the Weibull model. That is, in bathtub curve, there are three sections: (1) in the Section 1 (b<1), during the premature system lifetime, there is some lessening in the failure rate; (2) in the Section 2 (b=1), during its center life, there is a comparatively constant failure rate; and (3) in the Section 3 (b>1), there is an increasing failure rate until the end of the life of the system is reached. Initially, we did not know the initial guess b. Therefore, we assumed b=2 as a representative value (or initial guess) in the wearout (section 3). After parameter ALT, we can determine the value of b=3.5 for parametric ALT.
Comment 3. Can the authors make a simulation study for the parametric acceleration model?
Response: Based on the customer usage conditions, maximum stress is typically chosen in the range between the elastic limit and yield stress in the material. Based on the parametric acceleration model, the acceleration factor is defined as the ratio between the maximum stress and minimum stress is used to determine the shortened test time due to the elevated testing conditions.
For a dispenser system subjected to repeated impact load, the acceleration factor can be defined as the ratio of the maximum impact load and normal impact load. In the 2nd and 3rd ALT, the system was tested for more than 38,000 cycles minutes (the assigned mission time – RQ specification) – of the parametric ALTs. Because there was no problem in the test, regardless of accuracy of accelerated factor, we can expect to assure the targeted lifetime. To confirm the validity of the ALT for the mission cycles (or marketplace), we need to observe the introduction of the new design in the field to ensure that it passed the objective reliability.
Additionally, we modified some Figures and some quantities in the list of abbreviations that are important but were not explained previously.
I think this modified paper is now ready for further review because most of the comments have been considered. I would appreciate your review of this paper again.
Sincerely,
The authors
Reviewer 2 Report
- The parametric accelerated life testing should be explained a more detail and clearly.
- Authors of manuscript should explain how was estimated the greatest impact load anticipated by the user in releasing water.
- Which type of the load was evaluated in failure analysis. It should be explained in manuscript.
- It is mentioned that “Stress analysis, which may be integrated with fatigue analysis and parametric ALT, was performed by utilizing finite element analysis (FEA) (lines 529-530).”. FE model and main results of the analysis should be presented and explained
Author Response
Dear Sirs:
Thank you for your review of our paper. We modified it based on the comments of the reviewers. Below is a response to the review.
Comment 1. The parametric accelerated life testing should be explained a more detail and clearly.
Response: As you recommend, we added more explanation in the introduction to stress the innovation of this investigation and bibliographies in references.
Because some passages are incomprehensible and misleading in the description of the model (section 2.3), it was rewritten in a number of sections to better improve the English. This rewrite will have made clear some of the passages that may have been incomprehensible.
We also modified the detailed explanation in the section 2.5 (Case Study) in connection with the first section and the description of the model (section 2.3). Please check it.
Comment 2. Authors of manuscript should explain how was estimated the greatest impact load anticipated by the user in releasing water.
Response: As you recommend, we added the description with reference [40] in the section 2.5 (Case Study). That is, based on market data and laboratory test, the greatest impact load anticipated by the user in releasing water was approximately 15 - 20 N.
Comment 3. Which type of the load was evaluated in failure analysis? It should be explained in manuscript.
Response: As you recommend, we added the description in the section 3 (Results and Discussion). Please check it.
Comment 4. It is mentioned that “Stress analysis, which may be integrated with fatigue analysis and parametric ALT, was performed by utilizing finite element analysis (FEA) (lines 529-530).”. FE model and main results of the analysis should be presented and explained
Response: As you recommend, we added FE model and main results.
Additionally, we modified some Figures and some quantities in the list of abbreviations that are important but were not explained previously.
I think this modified paper is now ready for further review because most of the comments have been considered. I would appreciate your review of this paper again.
Sincerely,
The authors
Reviewer 3 Report
Section 2.3 and more precisely equations 7 - 20 can be the subject of another study. The paper can be revised without these equations.
Author Response
Dear Sirs:
Thank you for your review of our paper. We modified it based on the comments of the reviewers.
Comment 1. Section 2.3 and more precisely equations 7 - 20 can be the subject of another study. The paper can be revised without these equations.
Response: Because some passages are incomprehensible and misleading in the description of the model (section 2.3) including Equations (7) – (20), the paper was rewritten in a number of sections to better improve the English. This rewrite will have made clear some of the passages that may have been incomprehensible.
We also modified the detailed explanation in the section 2.5 (Case Study) in connection with the first section and the description of the model (section 2.3). Please check it. For verifying the effectiveness of the new dispenser system in the field, we can use formulations (41) and (42) that explain assessed life, LB, and approximated failure rate, λ, of the samples in each ALT.
We also added more explanation in the introduction to stress the innovation of this investigation and bibliographies in references. And we modified some texts in the introduction.
Additionally, we modified some Figures and some quantities in the list of abbreviations that are important but were not explained previously.
I think this modified paper is now ready for further review because most of the comments have been considered. I would appreciate your review of this paper again.
Sincerely,
The authors
Round 2
Reviewer 1 Report
Thank you for considering the notes, it will be better if you cite some refrences in the are of stress analysis like these papers
1- El-Azeem, S.O.A., Abu-Moussa, M.H., El-Din, M.M.M. et al. On Step-Stress Partially Accelerated Life Testing with Competing Risks Under Progressive Type-II Censoring. Ann. Data. Sci. (2022). https://doi.org/10.1007/s40745-022-00454-0
2- Samanta, D., Mondal, S., & Kundu, D. (2022). Optimal plan for ordered step-stress stage life testing. Statistics, 1-26.
Author Response
Dear Sirs:
Thank you for your review of our paper. We modified it based on the comments of the reviewers.
Comment 1. Thank you for considering the notes. It will be better if you cite some references in the stress analysis like these papers as follows:
1- El-Azeem, S.O.A., Abu-Moussa, M.H., El-Din, M.M.M. et al. On Step-Stress Partially Accelerated Life Testing with Competing Risks Under Progressive Type-II Censoring. Ann. Data. Sci. (2022). https://doi.org/10.1007/s40745-022-00454-0
2- Samanta, D., Mondal, S., & Kundu, D. (2022). Optimal plan for ordered step-stress stage life testing. Statistics, 1-26.
Response: As you recommend, we added them. Please check it.
I think this modified paper is now ready for further review because most of the comments have been considered. I would appreciate your review of this paper again.
Sincerely,
The authors
Reviewer 2 Report
I don't have additional remarks for the modified manuscript.
Author Response
-
Dear Sirs:
Thank you for your review of our paper. We modified it based on the comments of the reviewers.
Comment 1. I don't have additional remarks for the modified manuscript.
Response: Additionally, we added some references in the stress analysis like these papers as follows:
1- El-Azeem, S.O.A., Abu-Moussa, M.H., El-Din, M.M.M. et al. On Step-Stress Partially Accelerated Life Testing with Competing Risks Under Progressive Type-II Censoring. Ann. Data. Sci. (2022). https://doi.org/10.1007/s40745-022-00454-0
2- Samanta, D., Mondal, S., & Kundu, D. (2022). Optimal plan for ordered step-stress stage life testing. Statistics, 1-26.
I think this modified paper is now ready for further review because most of the comments have been considered. I would appreciate your review of this paper again.
Sincerely,
The authors
