Why Do Car Windshields Develop Cracks?
1 Answers
There are two main reasons for windshield cracking: 1. Natural factors causing windshield cracking: It is difficult to distinguish the specific cause of glass cracking due to glass quality issues and environmental factors. Cracks caused by these two factors share a common characteristic: there will be no external damage on the glass surface. Moreover, all natural glass cracks start from the edge of the glass. The primary reason is that laminated glass undergoes heating and cooling during the processing, which creates internal tensile stress and surface compressive stress. These two forces remain stable when balanced, otherwise, spontaneous cracking occurs. Due to internal defects in the glass material (such as impurities or surface scratches) or uneven heat treatment, tempered glass may develop uneven internal stress and localized stress concentration. Under the influence of external environmental factors (such as excessive temperature differences between the inside and outside), spontaneous cracking may occur. 2. Human factors causing windshield cracking: Human-induced windshield cracking can be divided into two scenarios: using tools or bare hands. It is possible for tempered glass in cars to crack when struck by bare hands. Cracks caused in this manner tend to be severe, with multiple fractures. Additionally, cracks caused by tools such as bricks or wrenches will show obvious external damage at the point of impact.
