Analysis types in FEM-Design
Depending on the current FEM-Design module you can do different calculations: displacement, internal forces, stresses, stability, imperfections, stability analysis, eigenfrequencies and/or seismic analysis. Some extra settings such as cracked-section analysis, non-linear behaviour etc. are also available for certain modules.
- Linear static analysis for all structure types
- Linear elastic and ideal plastic behavior of supports, edge connections, and trusses
- Static analysis according to second-order theory for spatial structures, global stability analysis-buckling shapes and critical loads for spatial structures
- Dynamic analysis-vibration shapes and eigen frequencies for all structure types
- Seismic calculation-response spectra method for 3D models
- Non-linear static analysis-supports resisting the only compression
- Cracking analysis-tracking of the cracking process
- 3D Solid Mohr Coulomb soil interaction
|Overall features||Advanced features|
Construction stages - Phase II
Determine the construction process effects on the displacement and internal force distribution of the finished structure with the Construction stages feature → Read more...
Finite element mesh in FEM-Design
FEM-Design offers a fully automatic finite element mesh generation by using optimized (factory default) or custom mesh settings.
The program generates mesh with elements having an average element size optimized for the structure and its environment (supports and loads). The process can contain automatic element refinement and peak smoothing algorithm according to the settings. The generated mesh can be modified with special easy-to-use edit and modify functions. → Read more...
Finite element types:
Depending on the FEM-Design version (FEM-Design Plate / Wall, 3D Structure / Frame), the engine uses the following finite elements:
|Element type||Finite elements|
|Line elements||Beam and truss|
|2D shell elements||4-, 8-, 9- nodes rectangular elements
3-, 6- nodes triangular elements
|3D volume elements||4-, 6-, 8-, 10-, 17-, 27- nodes elements|
Peak smoothing in FEM-Design
One of the most unique features of FEM-Design is the Peak smoothing that makes it possible to avoid the singularity problems.
As an effect of the mesh refinement, the calculated results are converging to the theoretical solution. The problem is that at certain places we get infinite inner forces according to the theory, so the inner forces increase each time by refining the mesh. These places could be: point supports, endpoints of edge supports, vertices of surface supports, endpoints of beams and columns, endpoints of intersection lines of adjoining surfaces, point loads, endpoints of line loads, vertices of surface loads etc. In practice, usually, the singularity problem occurs at supports because they heavily influence the inner forces (e.g. negative moments) in ratio. → Read more...
Peak smoothing region
The program defines peak smoothing regions to solve the possible singularity problems. Basically, these regions are the active zones in the environment of the singularity, where the inner forces change substantially as a result of mesh refinement. Peak smoothing regions can be generated automatically by the mesh generator or calculation processes. An automatic generation always results in circular peak smoothing regions with centre points placed in the location of the singularity. The radius of a circular smoothing region depends on the geometry of singularity locations.
All of the available calculation in FEM-Design can be performed with diaphragms or without diaphragms if the diaphragms were defined in the model. By the different types of calculations, the results will be analogous with the adjusted option.
The usage of the diaphragm tool is optimal by storeys of high-rise buildings but the diaphragm modeling tool is also useful by other engineering problems. The diaphragms could be several regions, but they must be horizontal. The shapes of the diaphragms can be arbitrary and they can be separated also on the specific storey levels. There can be more diaphragm regions on the same horizontal level and they will work independently from each other.
There are two different options for the diaphragm calculation:
- Rigid membrane
- Fully rigid
- The scientific explanation of diaphragm calculations in FEM-Design
- Video presentation of a diaphragm in FEM-Design