Filament Breakage: The Impact of Resistance and Temperature?

AI Thread Summary
Filament breakage in light bulbs is most likely to occur during the on/off cycling due to significant temperature changes that create maximum stress on the filament. The discussion highlights that bulbs often burn out when turned on, as the sudden temperature shift can lead to concentrated thermal stresses. Participants express interest in the underlying mechanics, suggesting that viscoplasticity and non-homogeneous temperature distribution also contribute to filament failure. The consensus indicates that deformation plays a critical role in the durability of the filament. Understanding these factors can help in mitigating filament breakage in light bulbs.
Gughanath
Messages
118
Reaction score
0
when is it more likely for the filament of a light bulp to break
 
Physics news on Phys.org
It is my experience that bulbs burn out when being turned on. Of course it is impossible to tell if a bulb burns out when being turned off you will not know until you try to turn it on. It makes sense to me that when the filament is feeling large changes in temperature it experiences a maximum stress, thus is more likely to break.

I say most bulbs burn out on On/Off cycling.
 
Here is probably more than you ever wanted to know and more.
http://members.misty.com/don/bulb1.html#wbt

Feel nearly an expert after reading that ... so essentially is the root cause concentrated thermal stresses or viscoplasticity & deformations overall due to the non-homogeneous temperature distribution (I've no idea about constitutive response of tungsten but supposedly it behaves similarly as other metals at such high relative temps?) ... I'd put a greater mark on the deformation?
 
wow...thank you everyone..problem solved :)
 
Back
Top