Runaway Linear Cracking describes?

Runaway Linear Cracking describes?

• A. A slow, controlled crack that releases gas over time.
• B. A crack caused by external impact only.
• C. A crack that forms due to internal heat buildup only.
• D. When a container is stressed and weakens due to metal fatigue; internal pressure exceeds recovery point and results in a rapidly growing crack.

Answer: (D)

Runaway linear cracking happens when a container is already weakened by metal fatigue and is under internal pressure. That combination creates a driving force at a crack tip strong enough to push the crack to grow very rapidly and uncontrollably along a line. It’s not about a slow, controlled release, nor about damage from impact or heat alone—the internal pressure plus the fatigued, weakened metal causes the crack to propagate quickly until failure. The essence is that sustained internal pressure interacts with fatigue damage to produce rapid crack growth beyond what the material can arrest.

Runaway linear cracking happens when a container is already weakened by metal fatigue and is under internal pressure. That combination creates a driving force at a crack tip strong enough to push the crack to grow very rapidly and uncontrollably along a line. It’s not about a slow, controlled release, nor about damage from impact or heat alone—the internal pressure plus the fatigued, weakened metal causes the crack to propagate quickly until failure. The essence is that sustained internal pressure interacts with fatigue damage to produce rapid crack growth beyond what the material can arrest.