One-dimensional analyses of striker impact on bar with different general impedance

Abstract

The particle velocity and stress in the striker and bar generated by the striker impact on a bar with different general impedance are formulated based on one-dimensional assumptions. Departure of the impact-generated stress wave towards the rear end of the striker and arrival of the release wave from the rear to the front of the striker constitute one impact cycle. In cases where Zs ≤ Zb ( Z is the general impedance, and subscripts ‘s’ and ‘b’ denote striker and bar, respectively), only one impact cycle takes place because the striker is stationary or separated from the impact surface after the first impact cycle. As a result, only a single (primary) pulse is observed in the bar and striker. In the case where Zs > Zb, however, multiple impact cycles take place because the striker is compressing the bar continually after the first cycle. As a result, a series of step-wise residual pulses follow the primary pulse in the bar and striker. The magnitudes of the stress and particle velocity in the bar and striker calculated using the formulated equations are quantitatively consistent with the results of the numerical simulations, verifying the formulated one-dimensional equations. The equations formulated in this study may be useful for better understanding the various wave interaction phenomena that take place in a pseudo-one-dimensional impact system and for modifying/designing an impact system.

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