Mathematical structural analysis of one way ribbed slabs was introduced
in this paper. The results of this analysis are compared with the results of
the finite element method by SAP program. In SAP program, the model
has been divided to frame elements "to represent ribs and beams" and
shell elements "to represent the slab and solid part". Before using the
SAP program to compare the results with the mathematical model, the
results of the SAP program are evaluated by three dimension analysis
through ANSYS program. The suggested mathematical analysis in this
work was more accurate than the traditional method and gives close
values of the induced moments of the ribs compared with the results of
finite element method.