The Compatible Stress Field Method is compliant with modern design codes. As the calculation models only use standard material properties, the partial safety factor format prescribed in the design codes can be applied without any adaptation. In this way, the input loads are factored, and the characteristic material properties are reduced using the respective strength reduction factors, exactly as in conventional concrete analysis.
Values of strength reduction factors are prescribed in ACI 318-19 Cl. 21.2. The default values for concrete and reinforcement are chosen based on the assumption that the typical example solved in the application is shear-controlled (based on Table 21.2.1 (b), (f), (g)). However, it is possible to model any type of element. Therefore, if a compression or tension-controlled element is assessed, the user has the option to change the strength reduction factor value in the Preferences.
\[ \textsf{\textit{\footnotesize{Fig. 42\qquad The setting of strength reduction factors in IDEA StatiCa Detail.}}}\]
Load factors for Strength combinations shall be defined according to ACI 318-19 Table 5.3.1.
Except as stated in Chapter 34, service-level load combinations are not defined in ACI 318-19. It is recommended to use combination rules based on Appendix C of ASCE/SEI 7-16. For all templates, load factors are already predefined.
\[ \textsf{\textit{\footnotesize{Fig. 43\qquad The setting of load factors in IDEA StatiCa Detail.}}}\]