Up until version 2024.d, CYPE 3D designed structures with linear analysis, meaning that all elements only had linear behaviour. Now, as of version 2024.d, elements with non-linear behaviour will also be implemented, along with the non-linear analysis.
Elements with non-linear behaviour implemented in this update are bars that only work in tension and supports with uplifts. The non-linear analysis of these two elements is part of two CYPE 3D modules ("Bars only in tension" and "Uplift at supports"), which means that, in order to be able to perform this analysis, the user's license must include them. Furthermore, users must also have the "OpenSees analysis engine" in their license.
Non-linear combinations
In the non-linear analysis, a superposition of loadcases is not possible, so users must perform an analysis of the model for each load combination to be studied. Therefore, the load combinations are defined on the basis of the loadcases defined in the job data and the types of combinations to be used for checking the elements of the structure are indicated for each of them.
The program allows users to define the combinations to be analysed in three ways:
- By manually entering each combination.
- By automatically generating all possible combinations from the situations defined in the project.
- By analysing the results obtained from a linear analysis.
Analysis
The program shall offer the option to perform the non-linear analysis when non-linear combinations have been defined and/or elements with non-linear behaviour have been entered into the model.
In the linear analysis, the behaviour of the non-linear elements shall be considered linear. A non-linear analysis can be carried out without having previously defined the combinations, in which case the program will determine the combinations that need to be analysed from the results of the linear analysis.
The checking of the bars is carried out with the results available after the analysis. If both linear and non-linear results are available, the program combines the results of both types of analysis according to the types of combination that apply to each element.
Viewing the results
As well as being able to view the results by loadcase and by combinations, as of this version, the results by non-linear combinations can also be checked. When checking by combinations, if a combination has been analysed as non-linear, it will be indicated with the suffix "NL". The results of the linear analysis for that combination can also be checked by ticking the "Only linear combinations" option.
Bars only in tension (new CYPE 3D module)
To consider a bar that works only in tension, enter a generic type of bar and, in the new "Behaviour" option, select the "Only tension" value.
Uplift at supports (new CYPE 3D module)
The program allows users to define the non-linearity of the supports for two types of elements. For nodes with external fixity, the working direction of the elastic restraint can be specified for each restrained degree of freedom.
For shells with subgrade modulus, users can specify whether the behaviour is "Linear" or "Only compression".
Reports
The program allows users to generate force reports for non-linear combinations for nodes, bars and shells.
