I mean your average party balloon, when it’s completely deflated, it seems you have to put extra effort into getting it going. As soon as it starts inflating, you need less effort.
In: Physics
I’m just an Electrical Engineer who had a lot of early-career exposure to material science and mechanical engineering stuff, but I’m pretty sure it’s just a stress/strain thing that applies to all materials, even nonlinear materials like polymers, right? don’t all materials have plastic and elastic regions of their stress vs. strain curves?
I used to work on high strength cables that were towed behind navy ships or laid on the bottom of the ocean, and they’d have really high axial tension strengths like 45klbf (thousand pounds-force), 100klbf, one was even a half million pounds axial tension strength. I used to get to be involved in pulling them to failure, which was like a bomb going off.
Anyway, just like with balloons, these cables, or more specifically the steel strength members in them, wouldn’t budge through tens of thousands of pounds on tension. We knew it was going to break though as we watched the elongation. At first, they wouldn’t stretch more than a few inches over a 50-foot length. As we approached the ultimate tensile strength though, suddenly the elongation would rapidly increase: as the steel transitioned from its elastic to plastic region, applying a constant or increasing force would stretch it more and more, and within a few seconds it would break. The stored energy released in microseconds, the cable would literally explode when the steel strength members finally gave way.
Latest Answers