Lecture30

# Lecture30 - ME 382 Lecture 30 COMBINED MODELING OF CREEP,...

This preview shows pages 1–2. Sign up to view the full content.

ME 382 Lecture 30 29/iii/06 1 C OMBINED MODELING OF CREEP , ELASTC AND PLASTIC DEFROMATION Total strain consists of elastic + plastic +creep component " total = elastic + plastic + creep For uniaxial case: ! elastic = / E ; plastic = A n ; d creep dt = ˙ o o # \$ % ( n Represented by a spring, dash-pot and friction element Example: Assume that an alloy with a modulus of 100 GPa exhibits steady-state power-law creep of the form ˙ ˜ H = 7.4 # 10 \$ 10 ˜ % H 5 exp \$ Q / RT ( ) s -1 , where Q = 160 kJ/mole, R = 8.31 J/mol.K, and ˜ H is in MPa. An applied uniaxial stress of 30 MPa is applied. What is the strain after 10,000 hours at 600 ° C? Creep rate with σ = 30 MPa at 600 ° C: ˙ = 4.75 " 10 # 12 s # 1 o = elastic + creep d o dt = d elastic dt + d creep dt d o dt = d / E ( ) dt + 7.4 # 10 \$ 10 5 exp \$ Q / RT ( ) s -1 ( σ in MPa) But if σ = 30 MPa & independent of time: d o dt = 4.75 " 10 # 12 o

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/20/2011 for the course ME 382 taught by Professor Garikipati during the Spring '08 term at University of Michigan.

### Page1 / 5

Lecture30 - ME 382 Lecture 30 COMBINED MODELING OF CREEP,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online