Eng-Tips is the largest forum for Engineering Professionals on the Internet.

Members share and learn making Eng-Tips Forums the best source of engineering information on the Internet!

  • Congratulations dmapguru on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

how can the plastic strain be greater than unity?

Status
Not open for further replies.

moeenhappy

Aerospace
Joined
Apr 17, 2015
Messages
7
Location
SE
Does anyone know how can the plastic strain be greater than unity? Such as in the benchmark manual 3.2.10 Indentation of a crushable foam plate:

As I Know that the formula for True strain is
True Strain = ln(1+nominal strain)
and if we consider a compression process then nominal strain should not be greater than 1 and thus max true strain will be
True Strain = ln(1+1)=ln(2)= 0.69

I know I am confusing somethings here, Kindly correct me

*CRUSHABLE FOAM HARDENING
0.2000E6, 0.0000
0.2577E6, 0.0094
0.2760E6, 0.0258
0.3053E6, 0.0452
0.3267E6, 0.0655
0.3623E6, 0.1084
0.3891E6, 0.1540
0.4250E6, 0.2405
0.4568E6, 0.3812
0.4738E6, 0.4600
0.5170E6, 0.6391
0.5862E6, 0.8570
0.6503E6, 0.9857
0.7470E6, 1.1324
0.9820E6, 1.2965
1.4702E6, 1.4808
2.7262E6, 1.6609
5.3911E6, 1.9000
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top