geomTrasf in 3d models

[giovannimilan]

Hi all,

In a 3d model (model basicBuilder -ndm 3 -ndf 6), I ve got beams with an angle respectively to the global coordinate system, do i really need to calculate exactly that angle for the orientation of the GeomTransf to be applied to the beam elements?

[selimgunay]

You don't need to calculate the angles. You can define the vecxz in the following link without any angles

http://opensees.berkeley.edu/wiki/index ... sformation

[giovannimilan]

got it now. also found an old example.

Cheers Selim,

[SadeghSalimian]

in some cases especially that your element is not parallel to global axis according to command manual you need to calculate a vector representing the direction of the local axis (z) of the element. it means you need an extra calculation to gain this vector. to me I always use the rotation matrices in 3D space to calculate this vector.