Abaqus usdfld - density and elasticity Modulus

[compmechanics]

Hello Colleagues,
I'm working on modeling a FGM plate in which Density and Elasticity Modulus changes through thickness of plate by an exponential function. I'm attaching the code i wrote below. It will be huge help if someone could look through and help with the errors.

I got the following error, 'Density has been defined as a function of temperature and/or field variables. For all elements except acoustic, heat transfer, coupled temperature-displacement and coupled thermal-electrical elements the density is a function of the initial values of temperature and field variables. It will not be updated if temperatures and field variables change during the analysis.'

 

[FEA way]

Check this thread:

https://www.eng-tips.com/viewthread.cfm?qid=460200

 

[compmechanics]

Hello,
basically I am trying to run a modal analysis on the fgm beam and see the effects of changing density and elasticity on the natural frequencies. The thread you linked you mentioned it is possible define spatial variation in the model. Please could you give some ideas on how to do this, it will be really helpful.

 

[FEA way]

Spatial variation of the density can be defined using the distribution feature (*DISTRIBUTION). A default value has to be given first and then densities are specified per element or element set. You can find the details in the documentation.

If you are using a natural frequency extraction procedure, you would have to run the analysis multiple times with different densities if you need anything more than spatial variation. Of course, Python scripting can help you automate this.