Definition(s)
Local Membrane Stress
If a membrane stress is averaged only over a localized portion of a cross-section, it is a local membrane stress. An example of a local membrane stress is the axial stress averaged over the area adjacent to the window of a dog coupling. Determining the area used for averaging a local stress requires judgement. Using a very small area results in the peak stress, not the local membrane stress. On the other hand, averaging over too large an area results in the general membrane stress, not the local membrane stress.
Source: API SPEC 16R, Specification for Marine Drilling Riser Couplings, Exploration and Production Department, First Edition, January 1997. Global Standards