Dyna result doesn't match Test result

by lambertlai
Tags: dyna, match, result, test
lambertlai is offline
Jul21-10, 10:56 PM
P: 4
I try many time to model a simple tensile test for steel MAT_024 but the graph doesn't match from Dyna result and Test result.
1. Collect data Tensile strain and stress convert to True stress and strain use formula True stress: eng. stress*(1+eng. strain). True strain= ln(1+eng. strain) and then the true strain convert to plastic strain = true strain - (true stress / Young modulus) and plot the graph

2. Use MAT_024 from dyna

3. Then I extract nodout and sec force.

LN1 is left node 1 (triangle on left)
RN1 is right node (triangle on right)

4. Eng stress= Force/Ao and eng. strain= delta Length / original length and plot the graph. (original area is 40, original length is 45mm)

Then the both result was different, why? What the misstake? Anyone can help me solve this problem?
Phys.Org News Partner Science news on Phys.org
Simplicity is key to co-operative robots
Chemical vapor deposition used to grow atomic layer materials on top of each other
Earliest ancestor of land herbivores discovered
john.phillip is offline
Jul22-10, 10:51 PM
P: 93
In the first figure, when you define the stress x plastic strain for the material, the maximum inputed value is around 0.5GPa for a strain of 0.3, but when you show the lab test stress x strain graph in the last figure, the maximum stress is around 0.37GPa for the same strain.
lambertlai is offline
Jul23-10, 12:37 AM
P: 4
The 1st figure is a plastic strain vs true stress as a input, is it right?
if true stress vs strain and lab test strain stress the max. stress is different right?

Register to reply

Related Discussions
How to get the result? Calculus 0
why i has that result.. Calculus & Beyond Homework 5
what is the result Set Theory, Logic, Probability, Statistics 2
An unlikely result General Math 5