The little metal pegs on a snow blower or a fuse in a circuit are examples I can think of.
‘Failsafe’ the word you are looking for?
“Ackshyually” incoming…
Failsafe has a specific meaning, describing a system that enters an inherently safe state in the case of a failure.
For example, semi truck parking brakes are actually disengaged by applying air pressure to the system; without air pressure the brakes are engaged automatically by heavy springs. Therefore most failures in the braking system would just result in being unable to disengage the brakes, as opposed to a truck rolling away.
So, while a sacrificial component like OP is describing could be designed as part of a failsafe, generally it’s a different design principle at play.
In electronics it’s a breaker or a fuse
I wanted to say fuse…
Fire sprinkler heads have a little glass vile filled with a glycerin based liquid holding the valve closed. When they heat up beyond a certain point, the liquid expands and bursts the vile, releasing the water from the sprinkler head. Note: only the sprinkler head exposed to the fire will dispense water, not the entire system as seen in movies. Also note: that water has been setting in an iron pipe for probably years and is absolutely disgusting.
Similarly, some commercial kitchens have a fuse-able link, which is a metal link in a chain made of some metal with a low melting point. When there’s a fire this link will melt and cause the roll up door between the kitchen and the rest of the building to slam shut.
After writing this I realize that it doesn’t necessarily answer the spirit of the question. But I guess these parts fail to protect the rest of the building, so maybe it does answer the question.
Mechanical fuse. Typically composed of shear pins or can be geartrain shafts manufactured with intentionally thinner cross-sections placed at strategic points. A plastic cog in some power tools serves a similar purpose.
In german its “Sollbruchstelle”, that would translate to “intended breaking point”.
