In some cases, according to EC3, it is necessary to consider global imperfections in order to consider possible defects in the plumb of the columns during the execution phase of the project. Here we present how Advance Design, Graitec’s proprietary software, can help.
WHAT THE EC3 STANDARD STATES
In some cases, according to EC3, it is necessary to consider the global imperfections in order to take into account the possible lack of plumbness of the columns during the execution phase of the project.
These initial geometric defects of the columns will result in the application of equivalent horizontal forces on the columns.
A horizontal force at the head φNed (along the local y or z axis) to simulate the inclination of the post and an opposite force at the foot so that the load applied at the head has no effect on the descent of the load. The value of φ is given by EC3.
APPLICATION OF ADVANCE DESIGN
Considering EC3 global imperfections on columns in Advance Design is done in 2 main steps. First, this calculation must be activated in the metal hypotheses.
Then it is necessary to activate and configure this calculation in the property sheet of the columns.
At the end of the metal expert calculation, the global imperfection forces on the columns are automatically generated in accordance with EC3 and are added to the ULS combinations.
We thus obtain ULS combinations with the global imperfection forces in one direction (ULS+/- imperfection) in addition to the basic ULS combinations.