CYPE is progressing in the implementation of structural design solutions based on non-linear analysis. This time, and after allowing this type of analysis in programs for connections (such as CYPE Connect) or steel structure detailing (such as StruBIM Steel), it is now time for CYPE 3D. The program can now perform the modelling and computational simulation by finite elements of the bars only in tension, uplift at supports and buckling. This has become a reality thanks to the release of three new modules that use the Open System for Earthquake Engineering Simulation (OpenSees) analysis engine.
With this new addition, presented in the 2024.d update, technicians will have more options when performing their calculations by having the possibility to use non-linear analysis, improving accuracy and providing more realistic results. To this end, the finite element method takes into account that the stress in an element may not be proportional to the deformation when the structural elements undergo significant alterations in the event, for example, of an earthquake impact.
" At CYPE we keep on improving our BIM structural solutions, incorporating new and better analysis options in our programs".Carlos Fernández, Technical Director at CYPE
Bars only in tension
For bars only in tension, the new CYPE module allows the bars to be deformed, which means that the tension is not proportional to the deformation. As a result, the program offers a more accurate solution than the linear analysis, as it considers the deformable behaviour of the material. There are many situations in which the material does not recover its original shape once it has been deformed.
To carry out a non-linear analysis of these tensioned bars in CYPE 3D, users must define the load combinations to be studied based on the loadcases defined in the construction data. When working, the module offers the option of performing the non-linear analysis both manually and automatically. For automatic analysis, CYPE 3D generates all possible combinations based on the loadcases defined in the project.
Uplift at supports
Uplifts at supports occur when, for example, a bar separates from the support. While in the linear analysis, the bar is always assumed to be in contact with the support, the non-linear analysis extends this option and includes the possibility of the bar detaching from the support point.
To analyse the non-linear behaviour of uplifts at supports, the new CYPE 3D module uses the OpenSees analysis engine to obtain a more precise solution than a linear analysis, considering the direction of the supports and the behaviour of the shells. It also generates reports with forces in structural elements.
Buckling analysis (global stability)
Buckling is a phenomenon in which a structure is suddenly deformed and loses its stability. To deal with this event, and as the latest new feature in this update, CYPE has incorporated buckling analysis using the finite element model. Just as in previous cases, CYPE 3D uses the OpenSees analysis engine through a specific module for extracting detailed results, such as the critical load factors for each combination and buckling mode, as well as the coefficient for each bar considered in the analysis.
Non-linear structural analysis is becoming increasingly more necessary when dealing with structures and increasing safety in the face of potentially complex situations such as earthquakes or extreme weather events. It provides more accurate results than linear analysis, as it considers the non-linear behaviour of the material and the structure.
CYPE has therefore been implementing the OpenSees analysis engine in its BIM structural design programs for some time. It is currently available in CYPE 3D, CYPE Connect, StruBIM Steel, StruBIM Foundations, StruBIM Design and StuBIM Analysis. Regarding this work, Carlos Fernández, CYPE's technical director, explains that the company "Will continue to improve our structural BIM solutions, incorporating new and better analysis options in our structural programs".