Project ForgeStrength of Materials
Stress & Strain
GATE 2017
Medium
A rod of length 20 mm is stretched to make a rod of length 40 mm. Subsequently, it is compressed to make a rod of final length 10 mm. Consider the longitudinal tensile strain as positive and compressive strain as negative. The total true longitudinal strain in the rod is
- A−0.5
- −0.69
- C−0.75
- D−1.0
Explanation
True strains are additive along a sequential deformation path and telescope to the overall length ratio: ε = ln(Lfinal/Linitial) = ln(10/20) = ln(0.5) ≈ −0.693. (Equivalently: ln(40/20)+ln(10/40) = 0.693−1.386 = −0.693.)
Source: GATE ME 2017 Session 2 (ME-2) (2017)
This question is part of a 15-day revision cycle — sign in and Project Forge will bring it back the day before you'd forget it.