Targeted steel frames by means of innovative moment resisting connections

A New Design Problem in the Formulation of a Special Moment Resisting Connection Device for Preventing Local Buckling

“…The device studied in the present paper is an evolution of that reported in other foregoing papers (see, e.g., [25][26][27][28][29][30][31]) and consists of a steel element with suitably assigned features aimed to substitute a portion of a given standard I-shaped steel profile. In Figure 1, the typical standard steel profile is sketched and its geometry is reported in Table 1.…”

“…From a geometrical point of view, the device possesses the following geometrical features: (i) it is characterized by symmetry with respect to three orthogonal barycentric planes; (ii) the thickness of flanges of the two outer portions is greater than that of the inner portion; (iii) the flanges of all portions possess a unique common medium plane; (iv) the thickness of web is the same in all the portions. It is important to emphasize that the actual version is an evolution of previous models (see, e.g., [31]) and, in particular, the main novelties are: (a) the flange width 𝑏 𝑖 of the inner part is assumed as different with respect to that of the outer portions; (b) the thickness of web is the same in all the portions. For a complete geometrical representation of the device, in Figure 3 the sketch of both the outer and inner portions, as well as a lateral view of the device, are reported while in Table 2 the adopted symbols are described.…”

“…Among the geometrical characteristics of the device reported above, the welding size 𝑠 has been introduced (Figure 3). In fact, from a technological point of view, the device is thought of as being obtained by the welding of steel plates with suitable thicknesses (for further details see [31]). Among the geometrical characteristics of the device reported above, the welding size s has been introduced (Figure 3).…”

“…To overcome these disadvantages, in the recent past, the authors proposed a new connection device realizing a special moment resisting connection for steel elements called the Limited Resistance Plastic Device (LRPD) [25][26][27][28][29][30][31]. The LRPD satisfies the requirements, ensuring the independence between strength and stiffness and, as a consequence, allowing an optimal mechanical performance for the structure that is suitably equipped.…”

A Discrete Macro Element Method for Modelling Ductile Steel Frames around the Openings of URM Buildings as Low Impact Retrofitting Strategy

“…Traditionally, such a technique was widely employed to restore the original in-plane stiffness and resistance of masonry walls where new openings had to be realized [2]. Alternatively, other strategies aim at replacing entire masonry walls with frames endowed with the same in-plane horizontal stiffness and resistance [3]. The retrofitting strategy here recommended was recently applied for the structural retrofitting of an existing masonry school building according to a structural design based on a synergic combination of Glass Fiber Reinforced Cementitious Matrix composites and dissipative steel frames around the openings (Progetto DPC-ReLUIS 2019-2021WP5: Interventi di rapida esecuzione a basso impatto ed integrati Case Study: SCUOLA IPSIA Vittoria (RG), in Italian).…”