MECHENG 382 Lecture : HW1+solution.pdf

• School: U of M
• Department: Mechanical Engineering
• Course: MECHENG 382
• Professor: All

Document Summary

Me 382 homework 1 solution: plastic deformation is shear deformation. Deformation caused by shear only change the shape of a material; it does not change the volume. However, plastic deformation dissipates energy in the form of heat. This may cause an increase in temeprature , and could lead to thermal expansion. However, provided the plastic deformation is done at a constant temperature, the volume will not change. N = 20% = 0. 2 d0 = 2r0 = 1mm = 10 3m l0 = 1m. T = 350 0. 4 t mpa = (3. 5 108) 0. 4 t pa. T = 350(ln(1 + n))0. 4 = 350 (ln(1 + 0. 2))0. 4 177. 18 mpa 177mpa. T = ln(1 + n) (b) (c) (d) 0 147. 65 0. 52 116 n. Energy(u ) = energy per unit volume(u) volume(v ) V = a0l0 = al (cid:90) t (cid:90) ln(1+ n) If material deforms by conserving its volume, a0l0 = al. The energy per unit volume is given as: u =