How to define paramaters of perzyna viscoplastic model?

  • Thread starter Thread starter zerrouki
  • Start date Start date
  • Tags Tags
    Model
Click For Summary

Discussion Overview

The discussion centers on modeling viscoplasticity using the Perzyna model in Ansys APDL, specifically focusing on how to determine the necessary parameters for the model. Participants explore the relevance of different testing methods, such as tensile tests and creep tests, in obtaining these parameters.

Discussion Character

  • Technical explanation, Experimental/applied, Debate/contested

Main Points Raised

  • One participant inquires about the methods for determining parameters for the Perzyna viscoplastic model, mentioning both tensile and creep tests.
  • Another participant suggests using an Instron machine for tensile strength and creep testing, noting the need for an environmental chamber for temperature control during creep tests.
  • A different participant questions whether tensile tests at varying strain rates or creep tests can be used to determine the parameters.
  • It is mentioned that the Instron can be programmed for different strain rates, but that strain rates influence yield and elongation, referencing ASTM methods for parameter determination.
  • A participant specifies that the material being tested is HDPE and asks about conducting tests with different strain rates using a Zwick Z100 machine.
  • Another participant advises consulting the operation manual of the Zwick Z100 and suggests referring to ASTM methods for guidance on setting machine parameters.

Areas of Agreement / Disagreement

Participants express varying opinions on the best methods for determining parameters, with no consensus reached on a single approach. The discussion includes multiple viewpoints on the suitability of tensile and creep tests.

Contextual Notes

Participants reference specific testing standards (ASTM methods) and equipment (Instron, Zwick Z100) but do not resolve the complexities of parameter determination or the implications of different testing conditions.

Who May Find This Useful

Researchers and engineers involved in material testing, particularly those working with viscoplastic materials and interested in modeling techniques in computational software.

zerrouki
Messages
6
Reaction score
0
Hello everyone
i want to model viscoplasticity using Ansys APDL, Perzyna and Peirce or Anand
model offer us to do this modeling, and each modèle Contains different parameters.
the question is: how to determine the parameters (if we can determine them experimentally, what is the concerned test "tensile test or creep").
thanks for help.
 
Engineering news on Phys.org
You'll need an Instron for the tensile strength elongation, and yield. The same machine can test for creep, but you need an environmental chamber for temp control. Creep is cold flow of a material under strain at a given temperature.
 
hello
is it possible to determine these paramaters using tensile tests with different strain rate or by using the creep test ?
thank's for help.
 
You can program the Instron for any strain rate within its capabilities, but strain rates affect yield, elongation at break. That is why there are ASTM methods for determining these parameters. Creep is done at constant strain. You can find physical properties of just about any resin in Modern Plastics data guidebook.

You can find elongation at 100%, elongation at break, elongation at yield, flexural modulus, and many other properties.
 
dear McHugh
the material to be tested is HDPE, the machine that can do this test is "Zwick Z100". how can I do the tests with different strain rates.
thanks

 
Consult your machine's operation manual. I am not familiar with this machine. I've always used Instrons. Consult ASTM methods for setting machine's parameters.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
3K
Replies
9
Views
3K
Replies
1
Views
1K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 45 ·
2
Replies
45
Views
6K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K