Etabs model attached , need help in detecting the problem in it.

[Robert-32]

Whats wrong with the attached file?? see the period of mode 1, it is not realistic. there is a problem with the slab but I cannot solve it. Any help??

 

[johnbridge231]

First divide the slab into smaller ones, so that a proper mesh is generated. Then this behaviour should be fixed.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[hsn199]

Do as john told you, in addition try to separate the Self wt and SIDL. Define a case "self" of type "dead" with self wt multiplier=1, and another case "SIDL" of type "super dead" with self multiplier =0.

then assign the dead load on slab based on SIDL case. Hope that helps.