Quiz-3-soln

# Quiz-3-soln - 4. Define engineering stress and strain, with...

This preview shows page 1. Sign up to view the full content.

Name_____________________________ Team No._______ ENGR 213 Quiz 3 2 OC 02 CLOSED BOOK and NOTES, INDIVIDUAL WORK 1. List the two major mechanisms for interdiffusion. 3 pts Vacancy and interstitial 2. Give the equation (eqn) for Fick’s first law, defining terms and their SI units. 3 pts J = -D (dC/dx) where J = flux = mass/area/time = kg/m 2 -s D = diffusion coef = area/time = m 2 /s C = concentration = mass/vol = kg/m 3 X = distance = length = m 3. Give the eqn for Fick’s second law, defining terms and units not already listed for Prob 2. 3 pts ( C/ t) = D ( 2 C)/( x 2 ) where t = time = s
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 4. Define engineering stress and strain, with SI units. 3 pts σ = F/A where F = force = N σ = stress = force/area = N/m 2 = Pa A = area over which force F applied = m 2 ε = ∆ l/l , where ∆ l = l i- l o l i = instantaneous length = m l = length prior to loading = m ε = strain = no units 5. On the axes below, sketch the curves for the semi-infinite solution at two different times. Be sure to indicate which curve represents the longer time. 3 pts Distance from interface Concentration, C X = 0 interface Short time Longer time...
View Full Document

## This homework help was uploaded on 03/26/2008 for the course ENGR 213 taught by Professor Dr.stubbs during the Fall '04 term at Texas A&M.

Ask a homework question - tutors are online