The component-based Finite Element Method (CBFEM) is a method for the computer-aided calculation and design of steel connections. It adopts the basic idea of the component method regulated in EN 1993-1-8, where the characteristics of a connection are determined based on the (non-linear) stiffnesses and strengths of the individual basic components. With the help of the component method, the load-bearing behavior of semi-rigid and deformable connections can also be estimated with good accuracy. In many cases, this allows for more economical design than assuming purely hinge connections or designing fully rigid connections.
While the stiffnesses and strengths of the basic components in the classical procedure are calculated based on semi-empirical formulas and must then be superimposed in a suitable manner, the basic components in CBFEM are discretely represented with the help of suitable finite elements and linked together. The stiffness of the connection as well as the exact force distribution into the individual basic components is then derived from the (non-linear) Finite Element calculation. Subsequently, the load-bearing capacity of the basic components can be checked considering the relevant design rules—such as EN 1993-1-8 or AISC 360. The advantages of the FE-supported over the classical component method include, among others:
- Greater flexibility in terms of defining basic components as well as their geometry and material properties
- Greater flexibility in the definition of contact and coupling conditions between the basic components
- Greater flexibility in the design of connections; the basic components can be effortlessly incorporated into complex connection geometries
- No restrictions regarding the load of the connection; the internal force distribution in the individual basic components results from calculations on the detailed FE model
- Better understanding of failure mechanisms through the analysis of deformations, forces, stresses, and strains in all parts of the connection
The Steel Joints Add-On, available as an extension for RFEM 6, incorporates the component-based Finite Element Method (CBFEM) and seamlessly links the connection design with the structural analysis of the entire structural system, thereby ensuring compatibility and interaction between the connection and frame model at all times.
