Thermal expansion coefficient out of bound

[yanchen291]

Hi Louise,

I am working on a model to predict elastic and thermal properties of polymers reinforced with plain weave glass fabrics. I am running into difficulties with the CTE in z direction being out of bound for certain geometries. It will be great if you could provide some insights. Below is an example.

test 1
- weave geometry: spacing = 1, width =0.8, fabric thickness = 0.2, height = 0.1
- CTE input bound [7.15, 46.3] ppm/c
- CTE output in z direction 45.5 ppm/c (within bound)
test 2
- weave geometry: spacing = 1, width =0.8, fabric thickness = 0.2, height = 0.08
- CTE input bound [7.15, 46.3] ppm/c
- CTE output in z direction 50.8 ppm/c (out of bound)

test 1 and test 2 have the same material input as follows.
*********************
*** MATERIALS ***
*********************
*Material, Name=Mat0
*Elastic
5.295e+03, 0.399
*Expansion
4.63e-05,
*Material, Name=Mat1
*Elastic, type=ENGINEERING CONSTANTS
4.9468e+04, 2.29e+04, 2.29e+04, 0.42, 0.12, 0.257, 8.0644e+03, 7.6e+03
7.6e+03
*Expansion, type=ORTHO
7.1497e-06, 2.14e-05, 2.14e-05