Learning Forum

[qadri4395]

Hi,

In Ansys Mechanical, nlcrwk and SENDCREEP are two expressions that calculate the creep strain energy density.

However, these two expressions calculated different results as shown below.

What is the difference between these two functions?

In another case, I managed to use the SENDCREEP expression but I will get an error if I use the nlcrwk expression.

Please see below the error.

What should I do to fix this?

For added context, I am trying to do a solder joint reliability study.

Let me know if more information is needed. 

[mohan.urs]

Hey,

From what i can see the NLCRWK is a valid expression to get creep strain energy density, which is also equivalent to the APDL command result item using PLESOL. However i was not able to find any expression for SENDCREEP. The SENDCREEP is an APDL command which is issued with PLESOL. So the result should match when you issue it using APDL postprocessing commands instead of user defined results. 

For the second case, can you check if you have the large deflection set to ON in the analysis settings and a proper creep model defined in the engineering material.

Regards,
Mohan Urs