Section cuts report forces in their own local coordinate systems. The local coordinate system for a user defined cutting plane is the same as the global coordinate system. The local coordinate system for a surface section cut is defined by the local Y-axis along the length of the line drawn, while the local Z-axis is perpendicular to the local Y-axis in the plane of the surface that the line was drawn on. The local X-axis is perpendicular to the plane on which the line was drawn.
To view the section cut local axes in Rhino, the following Grasshopper component combination can be used: