Safety Glass Breaks If Hit By Ceramic

Why will a piece of ceramic break safety glass but a similar sized rock just bounces off.

Safety glass breaks if hit by ceramic.

Breaking your car s windows in an emergency might be tougher than you think study says. I can break a big piece of tempered glass with a little ceramic chip. When safety glass is damaged in this way the damage propagates throughout the glass rapidly and the tension within the glass. Safety glass is the generic name for glass which has been treated to make it safer than normal glass.

Second the rock may have a hardness similar to the glass. The impact of the shard against the glass creates a tiny structural failing which rapidly spreads the tension through the rest of the screen causing it to break. Safety glass is designed to shatter differently from other types of glass to help prevent injuries from flying shards. This concentrates the force of the hit to a small enough area on the glass that it can scratch and fracture it.

When regular glass shatters it breaks into several sharp pieces and spreads everywhere. First this is impact not a uniform load. The glass may be able to resist 200kg of evenly distributed load but that is very different from a rock. Normal float glass can be dangerous.

When broken the pieces form razor sharp edges that can cause serious injury. Although effective spark plug fragments will not work all the time. Spark plugs are made of aluminum oxide ceramic which is exceptionally hard.