The steady-state response of the classic mass-spring-dashpot model when the spring stiffness decays exponentially with time (an aging spring) and the system is excited by a forcing function whose frequency is equal to the natural frequency of the system with the constant initial stiffness is investigated. The steady-state response is obtained in terms of the dumping and decay constants of the system and exhibits an oscillation about a nonzero value.

1.
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,
H.
, and
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T. T.
,
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An Aging Spring
,”
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, No.
2
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