Nonredundant Steel Tension Members
The most common types of NSTM members are tension flanges and parts of webs of flexural members such as beams and girders. Tension members of trusses, particularly eyebars, which commonly make up the lower chords of old trusses, can also be NSTM. Members subject to stress reversals are considered NSTM also.
Steel girders in two-girder bridges not evaluated for system redundancy in accordance with the TxDOT Bridge Design Manual are NSTM. Fracture of lower flanges in positive moment areas (midspan) and upper flanges in negative moment areas (over supports) can be expected to lead to full or partial collapse of the structure.
The majority of single member steel caps are NSTM. The exceptions are those where support columns or multiple cap members provide load path redundancy.