Local coordinate system.....URGENT

[nithinvl]

HI

In 2D, the bending is about local z-axis (which means, z-axis should be horizontal), as given under fiber section in http://opensees.berkeley.edu/OpenSees/m ... sermanual/.

But in the link http://opensees.berkeley.edu/wiki/index ... sformation, why is the local z-axis vertical for element 2 ??.....

I am finding problems in modelling, with confusion in this regard.

Kindly help me.

Regards

Nithin.

[vesna]

The example you are referring to is for 3D, not for 2D.

[Eslami]

Hi,
I also have confusion ith the link http://opensees.berkeley.edu/wiki/index ... sformation , I cant underestand how to define the local z-axis?

Although itis mentioned that vecxz should be used , but I can't underestand how this vector is defined when we don't know the z-axis?

Best regards,
Eslami

[vesna]

It is on you to set the local coordinate system for your elements. The only constraints for the local z axis are the following: (i) it can not coincide with the local x axis that goes from node I to node J of the element; (ii) local y and z axes need to follow the right-hand rule.