The State of Health of Electrical Connectors

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is correct and adequately explains the research carried out. Below I highlight some important deficiencies that should be reviewed by the authors.

1.       The contents of section 2 are widely collected in the literature. This section should be removed entirely and replaced with a reference.

2.       An experimental section must be included where the methods and instrumentation for measuring resistance are explained and the test setup is shown.

3.      In the bibliography section there are 17 references to publications by the authors. This is unacceptable. The bibliography must be extensively reviewed.

Author Response

Acknowledgement

The authors would like to express their thanks for the comments of reviewers which surely help in improving the quality of the paper.

 

Reviewer #1:

The paper is correct and adequately explains the research carried out. Below I highlight some important deficiencies that should be reviewed by the authors.

1. The contents of section 2 are widely collected in the literature. This section should be removed entirely and replaced with a reference.
2. An experimental section must be included where the methods and instrumentation for measuring resistance are explained and the test setup is shown.
3. In the bibliography section there are 17 references to publications by the authors. This is unacceptable. The bibliography must be extensively reviewed.
4. The contents of section 2 are widely collected in the literature. This section should be removed entirely and replaced with a reference.
   Response:

Shortened the general part of chapter 2 and additionally removed the chapters of Arrhenius (2.1.1) and Coffin-Manson (2.1.2) and shortened of “Failure in Time (FIT) Rate” (2.2).

 

2. An experimental section must be included where the methods and instrumentation for measuring resistance are explained and the test setup is shown.
   Response:

Added the section “3.5 Experimental” with a description and illustrations of the thermal cycling tests and the resistance measurements.

 

3. In the bibliography section there are 17 references to publications by the authors. This is unacceptable. The bibliography must be extensively reviewed.

Response:

Deleting some references at the end of section 1.2 since it is just a listing of different parameters affecting the force-resistance curve; replacing of other references.

Reviewer 2 Report

Comments and Suggestions for Authors

The reviewed article discusses the topic of "State of Health of Electrical Connectors". In the opinion of the reviewer, the article is interesting, although::

1) Equation formatting and equation numbering should be unified.

2) The article discusses the issues of damage prediction. A comparison with other methods typical of this type of problem would be desirable.

 

Author Response

Acknowledgement

The authors would like to express their thanks for the comments of reviewers which surely help in improving the quality of the paper.

 

Reviewer #2:

 

1. Equation formatting and equation numbering should be unified.
   Response:
   Equation format is unified, bold type of some equations has been removed, all equations are centred and the numberings right aligned.

 

2. The article discusses the issues of damage prediction. A comparison with other methods typical of this type of problem would be desirable.
   Response:
   The detailed electrical resistance development data of every single connector is used in this study. The comparable data in other investigations was not found. There are literatures available which focus on the prognosis of the degradation path and the remaining useful life of the connectors. They use different models such as autoregressive, autoregressive integrated moving average, Kalman filtering, Particle filtering, etc. to name a few. The results of our work cannot be directly compared with the results from these works.
   However, the extent of randomness in the measured and estimated lifetime of electrical connectors can be compared with some studies. In our investigation with percentile-based method, the absolute difference between the prognosed lifetime and the measured lifetime is in the range of 14 % to 60 %. This difference in the case of distribution-based methods is as high as 89 %. In the research by Gómez-Pau et al., the difference in the measured and estimated remaining useful life of the investigated individual connectors is in the range of 23 % to 71 % using the shortest test duration.
   [Á. Gómez-Pau, J.-R. Riba and M. Moreno-Eguila, "Time Series RUL Estimation of Medium Voltage Connectors to Ease Predictive Maintenance Plans," Applied Sciences, Vols. 10, , no. 24: 9041, 2020].

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is significant and has great sientific interest. There is an analyze of all the methods for estimating the reliability and the useful remaining lifetime of electrical connectors and proposes a data driven testing method based on short term field operations for accurate predictions.

It is relevant for the field and presented in a well-structured manner.

More tests should be done on different type connectors and especially on those that do not show failures in a short time to assess the accuracy of the conclusions of the study and the method.

Comments on the Quality of English Language

In equations 2, 5, 6 the minus sign should be visible.

In line 381 the symbols a and b should be in the same font format as in equation 17

Author Response

Acknowledgement

The authors would like to express their thanks for the comments of reviewers which surely help in improving the quality of the paper.

 

Reviewer 3

Minor editing of English language required

 

Conducted

 

In equations 2, 5, 6 the minus sign should be visible.

 

Corrected

 

In line 381 the symbols a and b should be in the same font format as in equation 17

 

Corrected

Reviewer 4 Report

Comments and Suggestions for Authors

The paper presents interesting results of a solid work, based on a significant amount of data. Yet please consider some remarks in order to improve your work:

In my opinion, too many general aspects from the field are included in this paper. Some of them can be dismissed either because they are widely mentioned in the specialty literature or are not usefully connected to the new information provided by this paper. This is not a “review” type paper. Actually only 5-6 pages out of 17 pages (references are not considered in this calculation) contain new and interesting info and the merit of them is somehow shaded by the “complementary” info.

Few references are very old (1974!) The authors should try to look for other more recent publications, even if their content is still valid.

References should be mentioned for many statements and Eqs. in the subsection 2.2, even if many of those information are widely known from the specialty literature.

If Fig. 4 is not original, reference should be inserted.

Reference no.9 misses information

Line 351 -> quotation marks are needed for the term „burn in phase”

Line 353 -> quotation marks are needed for the term „useful life of the component”

 

 

 

Comments on the Quality of English Language

Statements starting at lines 100 ,175, 188 need revision

Author Response

Acknowledgement

The authors would like to express their thanks for the comments of reviewers which surely help in improving the quality of the paper.

 

Reviewer #4:

 

1. In my opinion, too many general aspects from the field are included in this paper. Some of them can be dismissed either because they are widely mentioned in the specialty literature or are not usefully connected to the new information provided by this paper. This is not a “review” type paper. Actually only 5-6 pages out of 17 pages (references are not considered in this calculation) contain new and interesting info and the merit of them is somehow shaded by the “complementary” info.

Response:
Content is shortened in the introduction part with reductions in the section of “Acceleration Factor” and “Failure in Time (FIT) Rate”.

 

2. Few references are very old (1974!) The authors should try to look for other more recent publications, even if their content is still valid.

Response:
Former reference [7; Bock, E. M., Whitley, J. H.: Fretting corrosion in electrical contacts. In: 20th Annual Holm Seminar on Electrical Contacts. Harrisburg, Pennsylvania; 1974] removed as there are multiple references to the same statement.

 

3. References should be mentioned for many statements and Eqs. in the subsection 2.2, even if many of those information are widely known from the specialty literature.

Response:
Equations are given according to reference [37; Nelson, W. B., Accelerated testing: statistical models, test plans and data analysis, 2nd edition, John Wiley & Sons, Inc, Hoboken, 2004]; added the statement “The equations in the following section are according to [31].” in the beginning of section 2.2.

 

4. If Fig. 4 is not original, reference should be inserted.

Response:
Fig. 4 is an exemplary image and was created by the authors.

 

5. Line 351 -> quotation marks are needed for the term „burn in phase”

Response:
Quotation marks added.

 

6. Line 353 -> quotation marks are needed for the term „useful life of the component

Response:
Quotation marks added.

 

New editing of English language conducted.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The reviewer's questions have been correctly answered.