Messages about calculation data incoherence may be displayed in a situation when a reinforcement area cannot be calculated on the basis of user-defined reinforcement parameters.
This error is usually caused by defining reinforcement parameters for which distance values between internal reinforcement layers are too small. Situations like this are detected and you are prompted as follows.
The distance between bars of the perpendicular reinforcement (to main reinforcement) for panel X is Y% of its section. The incoherence error may occur.
Panels are located, for which the distance between internal reinforcement layers constitutes less than 20% of the thickness. Please note that when large cover values are defined in the reinforcement parameters, or when very small slab thickness values and large internal forces are defined, the message about data incoherence may be displayed. Even if the condition requiring 20% of section dimension between internal bars is fulfilled (it should be added, that approximately 50% of the thickness constitutes the value that is absolutely safe). Obviously, it is possible to perform correct calculations, despite failing to satisfy the above condition when internal forces are small. Calculated reinforcement will be relatively large due to a small arm of internal forces.
The most dangerous situation occurs when the thickness of a panel is smaller than the sum of four reinforcement diameters and both covers. This indicates that perpendicular (internal) reinforcement elements interpenetrate. Data incoherence is signaled and you will be prompted as follows.
The bars of perpendicular reinforcement (to main reinforcement) for panel X overlap each other. Check the correctness of the reinforcement parameters.
In both of these situations there are two possible solutions.
- Change the definition of slab reinforcement parameters that are used.
- Change the slab thickness.
The Axial force is too large prompt may appear during calculation of plate or shell reinforcement according to the American code ACI 318. Point 10.3.5 of that code determines the value of the maximal axial force that may be carried by an RC section.
When a force larger than the calculated P n(max) acts on 1 running meter, the Axial force is too large prompt is displayed.
The message Section dimensions are too small may appear in the following cases.
- Calculations are performed according to the French BAEL code. There are large bending moment values and small or zero axial force value. According to point B.6.6.1 of the mentioned code, compressive reinforcement cannot carry more than 40% of the moment acting on a section.
- Values of internal forces M and N are so large that compressive reinforcement is required, and simultaneously, the neutral axis is located exactly in the axis of that reinforcement. It is impossible to define the reinforcement for such a section.
- A defined section with the reinforcement parameters assigned to it is incorrect, since the gravity center of the tensile reinforcement is located above the gravity center of an RC section.
In all the above cases, section dimensions or a reinforcement cover should be changed.