What is the principle behind drilling circular holes at the start and end of cracks in car windshields?
Thread Content
In some cars, when cracks appear on the windshield, people deliberately make circular holes at the beginning and end of these cracks to slow down their progression. How can this practice be explained? Stress concentration in mechanics of materials – any advice?
I’m not sure what knowledge should be used to explain this; it reminds me of the concept of stress concentration in mechanics of materials
Eliminate the high stress peaks at the outer edge of the glass~
It disperses the stress at the crack tip, delaying crack propagation. Stress concentration leads to cracking.
Holes can cause stress concentration, but stress concentration is still better than the stress at the crack tip, right?
Crack stop hole: transforms the crack tip into a circular hole to prevent crack propagation.
Put simply, it means distributing the force that should act on a single point evenly across all the points along the circumference of the circular hole; therefore, the larger the circular hole, the less force each point experiences. :lol