Attached is a picture of two beams. The second beam has exactly the same properties and dimensions as the first one, but is rotated, say, by 45 degrees. I want to know if the second beam will have higher or lower stiffness in the X direction than the first beam. And an exlpanation for the answer will be appreciated.
The reason for asking this question is that when I was going over the Geometric Non-linearity effect inside a FEA software (like ANSYS), I read that if Large-Rotations are expected inside the model during solution, then Geometric Non-linearity should be turned ON. When I further researched that why does Large-Rotation need to have Geometric Non-linearity turned ON, it was discovered that the stiffness matrix changes because "If an element's oreintation changes (rotation), then the transformation of its local stiffness into global components will change", [as cited in Practical Finite Element Analysis, 1st Edition, Nitin].
I just want to understand the reason that why would changing the orientation (by rotating the beam) will change the local stiffness in a specific direction or axis, like X axis.