Adhered web-lapped semi-rigid pultruded FRP beam-to-column framing connections: Part 2 – Spring constant, strength prediction, and applications

The herein research focused on the definition of the spring constant, developing a predictive equation for strength, and a parametric study for adhered lapped semi-rigid pultruded fiber reinforced polymers (FRP) beam-to-column connections. The research is the second part of a two-part paper in which the first part focused on the experimental testing of 51 lapped adhered semi-rigid pultruded FRP beam-to-column connections in cyclic loading. The spring constant was determined based on analytical methods to determine the initial stiffness of the semi-rigid connections, net deformation due to flexural bending, and shear acting on the connection component (i.e., the column and the beam). A predictive equation to determine the strength of the semi-rigid connection was developed using an analytical approach and compared with the connection strength determined in the first part of the work, and a strength reduction factor (i.e., ϕ-factor) was defined to grant a standard-compliant level of reliability for the application of the developed predictive equation into load and resistance factor design (LRFD) approach. Finally, the possible applications of the results within the boundaries of LRFD design of pultruded FRP framing systems were discussed via a parametric study in which the results were applied and two real-world examples.