In version 2025.c, CYPE Connect and StruBIM Steel include the necessary tools to carry out the analysis of connections with dissipative elements. These tools can be used to design connections for earthquake-resistant structures in which energy dissipation is foreseen through the formation of plastic hinges, either in one of the elements of the connection or in the bars linked to it.
In the "Analysis" tab, a tool has been added to select the dissipative elements, offering users the option to choose between sections and plates. The material properties of the dissipative elements are transformed in the load cases marked as "Capacity design", considering the effects of material overstrength.
For Eurocodes and similar standards, the program will request the overstrength coefficient of the material, 𝛾ov, which amplifies both the yield strength and the ultimate strength of the dissipative elements. For American standards such as AISC360, NSR10, NTC-2023, among others, and other similar standards, the program will include in the material library the specific overstrength factors for each type of steel, Ry and Rt.
To analyse the connection for the over-resistance in dissipative elements, it is necessary to select not only the dissipative elements but also the "Capacity design" types of load cases in the list of load cases.
This new implementation allows users to design the connections so that the capacity of the connection is larger than that of the dissipative element while considering the over-resistance. In these cases, dissipative elements will experience large plastic deformations, which makes it difficult to converge the model, therefore, another relevant parameter in dissipative elements is the slope of the plastic span.
As detailed in the calculations manual, the constitutive law for plates and sections follows a bilinear model, where the slope of the plastic span is tan-¹(E/1000). For dissipative elements, in addition to incorporating the over-resistance coefficient as a multiplier of the yield stress, the slope of the plastic span is adjusted. In these elements, for a deformation of 5%, the stress will reach the elastic limit of the material, amplified by the over-resistance coefficient (𝛾ov or Ry, depending on the applied standard) and by the resistance reserve coefficient due to strain hardening, which is equal to 1.1. This slope, greater than tan-¹(E/1000), contributes to improve the convergence of the analysis.
