what is meant by tensile instability and its important in engineering design.?

Answer 1

Instability in Tensile Deformation - Solution Procedure
General Concept: The strength of strain hardening materials continually increases with increasing deformation. At necking the load carrying capacity starts to decrease ( load carrying ability decreases, strength which is a stress continues to increase). The load carrying capacity decreases because the effect decreasing cross-section area overcomes the effect of increasing material strength due to strain hardening


To identify the onset of necking the load, P, is used. When necking starts the load starts to decrease. Engineering stress is defined in terms of the specimen initial cross-section area, seng = P / Ao. So, a decrease in P results in a decrease in seng since Ao is constant. The onset of necking can be associated with the start of decreasing stress on the engineering stress-engineering strain plot.


Since there is a relation between engineering strain and true strain, the true strain at necking can be found if the engineering strain at necking is known.

http://www.menet.umn.edu/degarmo/Chapter2/soln2instability.html
http://www.menet.umn.edu/degarmo/Chapter2/tensileinstability.html

Answer 2

Tensile instability is the limiting tensile forces and moments which a structure can bear.

Answer 3

tensile strength is the stretch ability.