The statistical property of electrical breakdown in vacumm interrupters under impulse stress is experimentally studied.

But every time I feel that impulse I remind myself that in the past I have actually gotten better results, been able to focus more sharply and had less stress in my mind and body when I single-tasked.

In the present paper the dynamic stress distribution and stress con-centration factor in the neighbourhood of caverns under impulse loadingare given by using dynamic photoelastic method.