Transitional and rotational modes

[Moommoombaba]

I am building an irregular building model with a shape like a L but the bent is at 150 angle. The system is dual shear wall-moment frame RC structure. I notice the first mode is transitional mode in the x direction, second mode is the rotational mode and the third mode is the transitional mode in the y direction. I understand that since my building is irregular so I am getting the rotational mode being more dominant than the second transitional mode. However, it is vital to design a building that its first two modes are transitional. So my question is what is the most effective way to achieve this without changing my overall building shape and building system?

 

[Moommoombaba]

I don't know what's gotten into me. I mean "translational and rotational modes" and I couldn't find the edit post button.. My apologies

 

[monchie]

can you attached the model in .e2k file?

 

[jdgengineer]

Locate your center of rigidity and center of mass as close together as possible.

 

[asixth]

Not really. Any building with an offset core as the primary lateral resisting element will most likely have rotational mode as the second mode. CIRIA 102 has a section regarding building modes.