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Engineering Riddle – No. 4 (Materials) “A Point of No Returning”
Your welcome to disfigure, transform or twist with vigor, But let me be your warning, to save you dreadful mourning. When released from deformation, whether tension or compression, From my left get restoration, from my right, life-long mutation. I’m a bridge best not for burning, a point of no returning, Where rifts occur much faster, and cycling meets disaster. What material property am I?
This entry was posted in Engineering and tagged Civil Engineering, engineering mechanics, materials, Mechanical Engineering, mechanics of materials, strength of materials. Bookmark the permalink.
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I think “elastic limit” is more apt, although it and yield strength amount to the same thing.
The fourth line of the riddle seems to refer to the horizontal axis of the stress-strain curve. Elastic limit is the point at which stress and strain lose their proportionality and the specimen yields (often reducing the stress) and defining a new permanent length for the specimen when tension or compression is removed (the “point of no returning” in the fifth line).
A Point of No Returning
Answer: Yield Strength
Explanation:
Your welcome to disfigure, Transform or twist with vigor,
(In engineering, materials are intensionally stretched or compressed for desired compliance such as springs, or because it cannot be helped such as loaded bridges or other structures)
But let me be your warning, To save you dreadful mourning. When released from deformation, Whether tension or compression, From my left get restoration, From my right, life-long mutation.
(Yield Strength is a measure of strain under which the material is expected to return to it’s original length, whereas if the material is strained beyond the Yield Strength, the material will be plastically deformed and not likely return to it’s original length.)
I’m a bridge best not for burning, A point of no returning, Where rifts occur much faster, And cycling meets disaster.
(Exceeding the Yield Strength is like, as they say, burning a bridge; it is difficult to cross back over. Beyond the Yield Strength, cracks or rifts are more likely to occur especially if the material is exposed to a large number of stress or strain cycles.)
Answer please
The answer has been posted.