FAQ: Rebar Stress Analysis
- Cagin Yakar
Q: Why am I seeing higher/lower stress in the section graphic compared to the maximum reported stress ?
We iterate the position of the neutral axis, so there isn't a single exact location that directly matches with your entered moment-force couple. Instead, there is one point below that moment and another point above it. Graphically, we show the strains that are closest. When we report the stress value, we linearly interpolate between those two points. If you click on different points along the curve, you will see different neutral axis locations and their results.
For example, in the graph above, the stress value reported at the rebar fiber corresponds to a moment value of 18,578, whereas the moment value entered was 17,000. Therefore, the 23.91 ksi reported is the result of linear interpolation between the moment value of 12,401 (and its corresponding rebar stress value:17.36ksi) and the moment value of 18,758 (and its corresponding rebar stress value:26ksi) as seen in the figures below.
