Low-velocity impact behavior of vitreous-enameled steel plates

In the present work vitreous enamel, a special class of ceramic–glass material, was used as a coating for thin steel plate. The impact behavior of rectangular steel plate and coated steel plate (enameled steel plate) was studied by means of both experimental tests and numerical analysis. Experimental tests revealed the onset and growth of plate instability in the case of impact both on steel plates and on enameled steel plates. The instability was mainly located on the free edges and was particularly evident on the longer side of rectangular plates. The impactor initial energy that caused the instability onset in the case of enameled steel plate was about six times higher than the one that induced the instability in the steel plates. Numerical simulations were performed to better understand and study the experimentally observed instability phenomenon. Four numerical models were developed in order to study the influence of plate thickness and residual stresses acting on the enameled steel plates on plate instability. Results of numerical simulation revealed that residual stresses acting on enameled steel plated increased the value of force that caused the instability onset. Further numerical simulations showed that the increase of residual stresses acting on enameled steel plates highlighted the values relative to the instability force increase according to a non-linear trend.