Percentage of Error in Finite Element Analysis and Solutions
As it is known, within the scope of RYTEIE-2019, the analysis of masonry structures with finite elements is stipulated. Since the system model in masonry structures can be complex, it is necessary to be careful when modeling in the method that is extremely sensitive to the junctions of the nodes, such as finite elements.
If an element is hovering without support, it may cause all values to be zero or infinity in the system because it corrupts the finite element system matrix. Therefore, it is important to pay attention to the following points in modelling.
A1-Slabs must be attached to the walls and beams from the middle axis. In cases where it is not connected from the middle axis, the program may consider the relevant edge of the tile (depending on the fem sensitivity value in the project general settings) as disconnected.
A2-The length, thickness or modulus of elasticity of any building element should not be taken as zero.
A3- If there are walls resting on the floor on the upper floor, drawing beams on the ceiling of the lower floor whose height is equal to the thickness of the floor and whose width is equal to the width of the wall above will increase the accuracy of the analysis.
A4-Element intersections should be made from the middle axis. Element middle axles should be used in wall-to-wall, beam-wall connections. Beam vertical bond beam connections do not need to be made from the middle axis (for V5.3.7.5 and later), the program automatically creates link elements.
A5- If one wall is penetrating the other in the middle, it is not necessary to divide the stuck wall. StatiCAD makes automatic corrections in the analysis.
As in the A6-Lame case, the 1-2 cm wall parts between the door and the window should be deleted (Or the fem sensitivity value should be reduced so that the start and end points of the small wall piece are not connected to the same node). After wiping, the beam on the door and window can be made into one piece.
A7-Balcony parapet walls should not be included in the model. Because they are not connected to the diaphragm, it would be a more correct solution for the floor not to take a share from the earthquake shear force and to enter the system only as weight.
A8-Extra beams should not be drawn on the walls in their own direction.
A9- When the FEM sensitivity value is changed in the project general settings, the program aggregates the nodal points within the specified distance.
If you get the out of memory error during A10-Analysis, install the 64-bit version. Click for installation details. For large systems, a computer with 8Gb or more of RAM is recommended.
A11-Before sending your project as support, try to download and solve the latest version of the program. Because we are working on automatic creation of links with link elements in updates (not fully overlapping) elements.
R1-In most cases, the program gives the faulty element names and coordinates.