Question:
What do I have to specify in the RF‑/CONCRETE Columns and RF‑/CONCRETE Members add-on modules for concrete design if the stability analysis of a concrete frame structure should be a second order-analysis?
Answer:
In RF‑/CONCRETE Columns, the design is based on the nominal curvature method. For the bending resistance design, the program automatically determines whether it is sufficient to perform the standard design or the design with moments according to the second-order analysis. Therefore, it is necessary to create the load combinations with the option to determine internal forces according to the linear static analysis. Furthermore, the program determines the eccentricity by using imperfections. The designed load cases/combinations need to be specified without imperfections.
In RF‑/CONCRETE Members, you can perform the design according to the general method of analysis. The load combinations to be designed should be created with the option to determine internal forces according to the second-order analysis. Furthermore, it is necessary to consider the imperfections. In this case, a nonlinear calculation considering the cracked state is to be performed.