A Method for Evaluating Degradation Phenomenon of Electrical Contacts Using a Micro-Sliding Mechanism   — Minimal Sliding Amplitudes against Input Waveforms (2) —

Shin-ichi WADA; Koichiro SAWA

doi:10.1587/transele.E100.C.723

A Method for Evaluating Degradation Phenomenon of Electrical Contacts Using a Micro-Sliding Mechanism — Minimal Sliding Amplitudes against Input Waveforms (2) —

Shin-ichi WADA, Koichiro SAWA

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Authors previously studied the degradation of electrical contacts under the condition of various external micro-oscillations. They also developed a micro-sliding mechanism (MSM2), which causes micro-sliding and is driven by a piezoelectric actuator and elastic hinges. Using the mechanism, experimental results were obtained on the minimal sliding amplitude (MSA) required to make the electrical resistance fluctuate under various conditions. In this paper, to develop a more realistic model of input waveform than the previous one, T_s/2 is set as the rising or falling time, T_c as the flat time, and τ/2 as the duration in a sliding period T (0.25 s) of the input waveform. Using the Duhamel's integral method and an optimization method, the physical parameters of natural angular frequency ω₀ (12000 s^-1), damping ratio ζ (0.05), and rising and falling time T_s (1.3 or 1.2 ms) are obtained. Using the parameters and the MSA, the total acceleration of the input TA (=f(t)) and the displacement of the output x(t) are also obtained using the Fourier series expansion method. The waveforms x(t) and the experimental results are similar to each other. If the effective mass m, which is defined as that of the movable parts in the MSM2, is 0.1 kg, each total force TF (=2mTA) is estimated from TA and m. By the TF, the cases for 0.3 N/pin as frictional force or in impulsive as input waveform are more serious than the others. It is essential for the safety and the confidence of electrical contacts to evaluate the input waveform and the frictional force. The ringing waveforms of the output displacements x(t) are calculated at smaller values of T_s (1.0, 0.5, and 0.0 ms) than the above values (1.3 or 1.2 ms). When T_s is slightly changed from 1.3 or 1.2 ms to 1.0 ms, the ringing amplitude is doubled. For the degradation of electrical contacts, it is essential that T_s is reduced in a rectangular and impulsive input. Finally, a very simple wear model comprising three stages (I, II, and III) is introduced in this paper. Because T_s is much shorter in a rectangular or impulsive input than in a sinusoidal input, it is considered that the former more easily causes wear than the latter owing to a larger frictional force. Taking the adhesive wear in Stages I and III into consideration, the wear is expected to be more severe in the case of small damped oscillations owing to the ringing phenomenon.

Publication: IEICE TRANSACTIONS on Electronics Vol.E100-C No.9 pp.723-731

Publication Date: 2017/09/01

Publicized

Online ISSN: 1745-1353

DOI: 10.1587/transele.E100.C.723

Type of Manuscript: Special Section PAPER (Special Section on Recent Development of Electro-Mechanical Devices)

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Authors

Shin-ichi WADA
TMC System Co. Ltd.
Koichiro SAWA
Nippon Institute of Technology

Keyword

electrical contact, micro-sliding mechanism, frictional force, minimal sliding amplitude, input waveform, rising or falling time, wear

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Shin-ichi WADA, Koichiro SAWA, "A Method for Evaluating Degradation Phenomenon of Electrical Contacts Using a Micro-Sliding Mechanism — Minimal Sliding Amplitudes against Input Waveforms (2) —" in IEICE TRANSACTIONS on Electronics, vol. E100-C, no. 9, pp. 723-731, September 2017, doi: 10.1587/transele.E100.C.723.
Abstract: Authors previously studied the degradation of electrical contacts under the condition of various external micro-oscillations. They also developed a micro-sliding mechanism (MSM2), which causes micro-sliding and is driven by a piezoelectric actuator and elastic hinges. Using the mechanism, experimental results were obtained on the minimal sliding amplitude (MSA) required to make the electrical resistance fluctuate under various conditions. In this paper, to develop a more realistic model of input waveform than the previous one, T_s/2 is set as the rising or falling time, T_c as the flat time, and τ/2 as the duration in a sliding period T (0.25 s) of the input waveform. Using the Duhamel's integral method and an optimization method, the physical parameters of natural angular frequency ω₀ (12000 s^-1), damping ratio ζ (0.05), and rising and falling time T_s (1.3 or 1.2 ms) are obtained. Using the parameters and the MSA, the total acceleration of the input TA (=f(t)) and the displacement of the output x(t) are also obtained using the Fourier series expansion method. The waveforms x(t) and the experimental results are similar to each other. If the effective mass m, which is defined as that of the movable parts in the MSM2, is 0.1 kg, each total force TF (=2mTA) is estimated from TA and m. By the TF, the cases for 0.3 N/pin as frictional force or in impulsive as input waveform are more serious than the others. It is essential for the safety and the confidence of electrical contacts to evaluate the input waveform and the frictional force. The ringing waveforms of the output displacements x(t) are calculated at smaller values of T_s (1.0, 0.5, and 0.0 ms) than the above values (1.3 or 1.2 ms). When T_s is slightly changed from 1.3 or 1.2 ms to 1.0 ms, the ringing amplitude is doubled. For the degradation of electrical contacts, it is essential that T_s is reduced in a rectangular and impulsive input. Finally, a very simple wear model comprising three stages (I, II, and III) is introduced in this paper. Because T_s is much shorter in a rectangular or impulsive input than in a sinusoidal input, it is considered that the former more easily causes wear than the latter owing to a larger frictional force. Taking the adhesive wear in Stages I and III into consideration, the wear is expected to be more severe in the case of small damped oscillations owing to the ringing phenomenon.
URL: https://global.ieice.org/en_transactions/electronics/10.1587/transele.E100.C.723/_p

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@ARTICLE{e100-c_9_723,
author={Shin-ichi WADA, Koichiro SAWA, },
journal={IEICE TRANSACTIONS on Electronics},
title={A Method for Evaluating Degradation Phenomenon of Electrical Contacts Using a Micro-Sliding Mechanism — Minimal Sliding Amplitudes against Input Waveforms (2) —},
year={2017},
volume={E100-C},
number={9},
pages={723-731},
abstract={Authors previously studied the degradation of electrical contacts under the condition of various external micro-oscillations. They also developed a micro-sliding mechanism (MSM2), which causes micro-sliding and is driven by a piezoelectric actuator and elastic hinges. Using the mechanism, experimental results were obtained on the minimal sliding amplitude (MSA) required to make the electrical resistance fluctuate under various conditions. In this paper, to develop a more realistic model of input waveform than the previous one, T_s/2 is set as the rising or falling time, T_c as the flat time, and τ/2 as the duration in a sliding period T (0.25 s) of the input waveform. Using the Duhamel's integral method and an optimization method, the physical parameters of natural angular frequency ω₀ (12000 s^-1), damping ratio ζ (0.05), and rising and falling time T_s (1.3 or 1.2 ms) are obtained. Using the parameters and the MSA, the total acceleration of the input TA (=f(t)) and the displacement of the output x(t) are also obtained using the Fourier series expansion method. The waveforms x(t) and the experimental results are similar to each other. If the effective mass m, which is defined as that of the movable parts in the MSM2, is 0.1 kg, each total force TF (=2mTA) is estimated from TA and m. By the TF, the cases for 0.3 N/pin as frictional force or in impulsive as input waveform are more serious than the others. It is essential for the safety and the confidence of electrical contacts to evaluate the input waveform and the frictional force. The ringing waveforms of the output displacements x(t) are calculated at smaller values of T_s (1.0, 0.5, and 0.0 ms) than the above values (1.3 or 1.2 ms). When T_s is slightly changed from 1.3 or 1.2 ms to 1.0 ms, the ringing amplitude is doubled. For the degradation of electrical contacts, it is essential that T_s is reduced in a rectangular and impulsive input. Finally, a very simple wear model comprising three stages (I, II, and III) is introduced in this paper. Because T_s is much shorter in a rectangular or impulsive input than in a sinusoidal input, it is considered that the former more easily causes wear than the latter owing to a larger frictional force. Taking the adhesive wear in Stages I and III into consideration, the wear is expected to be more severe in the case of small damped oscillations owing to the ringing phenomenon.},
keywords={},
doi={10.1587/transele.E100.C.723},
ISSN={1745-1353},
month={September},}

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TY - JOUR
TI - A Method for Evaluating Degradation Phenomenon of Electrical Contacts Using a Micro-Sliding Mechanism — Minimal Sliding Amplitudes against Input Waveforms (2) —
T2 - IEICE TRANSACTIONS on Electronics
SP - 723
EP - 731
AU - Shin-ichi WADA
AU - Koichiro SAWA
PY - 2017
DO - 10.1587/transele.E100.C.723
JO - IEICE TRANSACTIONS on Electronics
SN - 1745-1353
VL - E100-C
IS - 9
JA - IEICE TRANSACTIONS on Electronics
Y1 - September 2017
AB - Authors previously studied the degradation of electrical contacts under the condition of various external micro-oscillations. They also developed a micro-sliding mechanism (MSM2), which causes micro-sliding and is driven by a piezoelectric actuator and elastic hinges. Using the mechanism, experimental results were obtained on the minimal sliding amplitude (MSA) required to make the electrical resistance fluctuate under various conditions. In this paper, to develop a more realistic model of input waveform than the previous one, T_s/2 is set as the rising or falling time, T_c as the flat time, and τ/2 as the duration in a sliding period T (0.25 s) of the input waveform. Using the Duhamel's integral method and an optimization method, the physical parameters of natural angular frequency ω₀ (12000 s^-1), damping ratio ζ (0.05), and rising and falling time T_s (1.3 or 1.2 ms) are obtained. Using the parameters and the MSA, the total acceleration of the input TA (=f(t)) and the displacement of the output x(t) are also obtained using the Fourier series expansion method. The waveforms x(t) and the experimental results are similar to each other. If the effective mass m, which is defined as that of the movable parts in the MSM2, is 0.1 kg, each total force TF (=2mTA) is estimated from TA and m. By the TF, the cases for 0.3 N/pin as frictional force or in impulsive as input waveform are more serious than the others. It is essential for the safety and the confidence of electrical contacts to evaluate the input waveform and the frictional force. The ringing waveforms of the output displacements x(t) are calculated at smaller values of T_s (1.0, 0.5, and 0.0 ms) than the above values (1.3 or 1.2 ms). When T_s is slightly changed from 1.3 or 1.2 ms to 1.0 ms, the ringing amplitude is doubled. For the degradation of electrical contacts, it is essential that T_s is reduced in a rectangular and impulsive input. Finally, a very simple wear model comprising three stages (I, II, and III) is introduced in this paper. Because T_s is much shorter in a rectangular or impulsive input than in a sinusoidal input, it is considered that the former more easily causes wear than the latter owing to a larger frictional force. Taking the adhesive wear in Stages I and III into consideration, the wear is expected to be more severe in the case of small damped oscillations owing to the ringing phenomenon.
ER -