@misc{12761,
  abstract     = {{For modern machines, factories and electric and autonomous vehicles, the importance of vreliable electrical connectors cannot be overstated. With an increasing number of connectors being used in machines, factories and vehicles, ensuring their reliability is crucial for comfort and safety alike. One of the key indicators of reliability is the lifetime of connectors. To evaluate the lifetime of electrical connectors, a testing method and a model for calculating their lifetime based on the test data were developed. The results from these tests were compared to failure analysis data from long-term field operations. The findings indicate that the laboratory tests can accurately reproduce the main failures observed in the field. However, such lifetime tests can be time- and labor-intensive. To address this challenge, a data-driven method is proposed that predicts the lifetime of electrical connectors using statistical analysis of electrical contact resistance data collected from short-term tests. The predictions from this method were compared to actual results obtained from long-term tests. A strong correlation was observed between the contact resistance development in short-term tests and the number of failures in later stages of testing. Thus, apart from predicting the lifetime of connectors, this method can also be applied for failure prognosis in real-time operations.}},
  author       = {{Song, Jian and Shukla, Abhay Rammurti and Probst, Roman}},
  booktitle    = {{Machines}},
  issn         = {{2075-1702 }},
  keywords     = {{electrical connectors, accelerated life testing, statistical model, lifetime prognosis, reliability, state of health}},
  number       = {{12}},
  pages        = {{474}},
  publisher    = {{MDPI}},
  title        = {{{The State of Health of Electrical Connectors}}},
  doi          = {{https://doi.org/10.3390/machines12070474}},
  volume       = {{7}},
  year         = {{2024}},
}

@misc{12891,
  abstract     = {{Copper alloy metal strips are widely used to manufacture electrical connectors. These connectors experience stress relaxation during operation. The reduced contact force may lead to contact failure. For the given design of connectors, the contact force is proportional to the Young's modulus which depends on interatomic bonds, alloying elements and the microstructure of metal grains. According to the literature, it is assumed that Young's modulus does not change significantly during long-term mechanical stress and aging at temperatures below the recrystallization temperature of copper alloys. Based on this assumption, the relaxation of connectors from lifetime tests and from long-term used field vehicles can be determined by the comparison of spring deflection of connectors before and after long-term tests or long-term use. The focus of this paper is to answer the question, whether this assumption is accurate. For this purpose, the influence of long-term thermal and mechanical loads on the Young's modulus of various copper alloys is investigated. The temperature in test approximately matches the maximum design temperature of automotive connectors and the mechanical stress is comparable to that in a typical connector.}},
  author       = {{Bünting, Karolin and Shukla, Abhay Rammurti and Song, Jian}},
  booktitle    = {{	 Electrical contacts - 2024 : proceedings of the Sixty‐Ninth IEEE Holm Conference on Electrical Contacts : 6-10 October 2024, Annapolis, MD, USA }},
  isbn         = {{979-8-3315-2907-9}},
  keywords     = {{Young's modulus, thermal and mechanical loads, spring deflection, relaxation}},
  location     = {{Annapolis, MD, USA }},
  publisher    = {{IEEE}},
  title        = {{{The Influence of Long Term Thermal and Mechanical Loads on the Young's Modulus of Cu-Alloys - Determination of Stress Relaxation in Electrical Connectors}}},
  doi          = {{10.1109/holm56222.2024.10768449}},
  year         = {{2024}},
}

@misc{11348,
  abstract     = {{Lifetime is an important feature defining the reliability of electrical connectors. In general practice, the lifetime tests required for reliability estimation are time and labor intensive. In our previous work, a data driven method using a statistical process, with an application of probability distributions such as standard normal distribution and generalized extreme value (GEV) distribution with negative skewness to predict degradation paths, was introduced for estimation of the lifetime and FIT rate with the help of electrical contact resistance data collected from short term tests. The proposed method proved its significance by showing the possibility of drastic reduction in the lifetime test duration required for reliability determination. In this work, a non-parametric distribution free method using percentiles of actual measured contact resistances is used for determining the lifetime as against the percentiles of probability distribution used in previous work, thereby simplifying the process further and leading to an even more precise estimation. The lifetimes calculated from parametric and non-parametric methods are compared to highlight the significance of distribution free method in reliability estimation.}},
  author       = {{Shukla, Abhay Rammurti and Martin, Robert and Probst, Roman and Song, Jian}},
  booktitle    = {{Microelectronics Reliability}},
  issn         = {{0026-2714}},
  keywords     = {{Electrical and Electronic Engineering, Surfaces, Coatings and Films, Safety, Risk, Reliability and Quality, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}},
  publisher    = {{Elsevier }},
  title        = {{{Comparison of different statistical methods for prediction of lifetime of electrical connectors with short term tests}}},
  doi          = {{10.1016/j.microrel.2023.115216}},
  volume       = {{150}},
  year         = {{2023}},
}

@misc{11351,
  author       = {{Song, Jian and Shukla, Abhay Rammurti}},
  booktitle    = {{Elektrische und optische Verbindungstechnik 2023 : Tagungsband der VDE/VDI GMM-Fachtagung : 9. Symposium Connectors}},
  editor       = {{Song, Jian}},
  location     = {{Lemgo}},
  pages        = {{209 -- 221}},
  publisher    = {{Labor für Feinsystemtechnik, TH OWL}},
  title        = {{{Influence of surface roughness on contact behavior.}}},
  year         = {{2023}},
}

@misc{11356,
  abstract     = {{• Surface roughness has significant influence on contact area
• Real contact area can be predicted with good precision by simplifying roughness model using core roughness Rk and average groove width RSM
• Higher precision can be achieved by proper selection of material ratio
• The proposed method can be effectively used for predicting contact resistance for given contact conditions}},
  author       = {{Shukla, Abhay Rammurti and Song, Jian}},
  location     = {{Busan}},
  title        = {{{Influence of surface roughness and force on real contact area Busan}}},
  year         = {{2023}},
}

@misc{11360,
  abstract     = {{The state of health and lifetime estimation process of electrical connectors via lifetime tests is a time and labor intensive process. In our previous work, a correlation between the contact resistance developments in the early stages of lifetime tests of electrical connectors with the final results was established using a data driven statistical process based on probability distribution. Also, state of health indicators for prognosis of lifetime were introduced. In this work, the state of health indicators have been optimized. The sensitivity analysis is performed with regards to the selection of the appropriate amount of test data based on test duration for the reliable prognosis of the state of health and the characteristic lifetime. Through this the possibility of further reduction of test duration required for the reliable prognosis of state of health is investigated. Based on the results of analysis, a guideline for the determination of the duration of lifetime tests which lead to a reliable prediction of lifetime of connectors can be provided. Also, an assessment of the state of art in the prognosis of the lifetime of electrical connectors has been presented.}},
  author       = {{Song, Jian and Shukla, Abhay Rammurti and Probst, Roman}},
  booktitle    = {{2023 IEEE 68th Holm Conference on Electrical Contacts (HOLM)}},
  isbn         = {{979‐8‐3503‐4244‐4}},
  issn         = {{2158‐9992}},
  keywords     = {{accelerated life testing, test duration, contact resistance, statistical model, connector reliability}},
  location     = {{Seattle}},
  pages        = {{200--208}},
  publisher    = {{IEEE}},
  title        = {{{Advances in Evaluation of State of Health of Electrical Connectors}}},
  doi          = {{10.1109/holm56075.2023.10352279}},
  year         = {{2023}},
}

@misc{11361,
  author       = {{Shukla, Abhay Rammurti and Martin, Robert and Probst, Roman and Song, Jian}},
  location     = {{Toulouse (France)}},
  title        = {{{Comparison of different statistical methods for prediction of lifetime of electrical connectors with short term tests}}},
  year         = {{2023}},
}

@misc{11362,
  author       = {{Song, Jian and Probst, Roman and Shukla, Abhay Rammurti and Bünting, Karolin}},
  location     = {{Fukuoka, Japan }},
  title        = {{{Influence of tribological properties of contact coatings on the long term behavior of electrical contacts}}},
  year         = {{2023}},
}

@inproceedings{6290,
  author       = {{Langer, T. and Shukla, Abhay Rammurti and Yuan, Haomiao and Probst, Roman and Nolte, Steffen and Song, Jian}},
  booktitle    = {{Tagungsband der VDE/VDI-GMM-Fachtagung „Symposium Connectors“}},
  location     = {{Lemgo}},
  pages        = {{28 -- 43}},
  title        = {{{Parametric Optimization of Connectors by means of Coupled Simulation}}},
  year         = {{2021}},
}

@inproceedings{6324,
  author       = {{Yuan, Haomiao and Hilmert, Dirk and Shukla, Abhay Rammurti and Song, Jian}},
  booktitle    = {{Proceedings of the 66th IEEE Holm Conference on Electrical Contacts}},
  title        = {{{Effect of Direction of Motion on Fretting Corrosion Behaviour}}},
  year         = {{2020}},
}

@inproceedings{6310,
  author       = {{Song, Jian and Yuan, Haomiao and Shukla, Abhay Rammurti}},
  booktitle    = {{Proceedings of 15th Arnold Tross Colloquium}},
  location     = {{Hamburg}},
  title        = {{{Wear and fretting corrosion of coatings of electrical contacts - Some new aspects}}},
  year         = {{2019}},
}

@inproceedings{6326,
  author       = {{Song, Jian and Yuan, Haomiao and Shukla, Abhay Rammurti and Koch, Christian and Hilmert, Dirk}},
  booktitle    = {{Proceedings of the 65th IEEE Holm Conference on Electrical Contacts}},
  location     = {{Milwaukee}},
  title        = {{{Correlation of connector contact failures in accelerated testing and in long-term use field vehicles}}},
  year         = {{2019}},
}