PCB Material Properties

[gpavlik8]

I'm working on a structural analysis involving a box with 3 PCBs. Looking at the material properties for the PCB, I see tensile strength and flexural strength in both the "length" direction and the "cross" direction. Can someone explain the difference between the two? Does it have to do with sample orientation during testing? Testing direction relative to fiber orientation for a composite material?

This is what I'd assume is "Tensile Strength, Length Direction"

https://www.youtube.com/watch?v=InzDCs8OBxk

but I'm not sure how it'd change for "cross direction".

 

[FEA way]

The PCB material is treated as orthotropic, like in the case of wood. In most FEA programs such material are supported and you have to specify the elastic constants in three orthogonal directions, based on the coordinate system used for material definition.