- The bonded post-tensioning stress-strain curves are used, but altered as detailed below.
- For service level (elastic) analysis, unbonded tendon stresses are assumed to be independent of section strains.
- The tendon stress is never reduced below σ
p.ef
.
- The tendon stress is never exceeds fpy.
- The tendon stress is limited by code section 8.1.6 equation (a) or (b) as appropriate.
Note: The program does not consider section 19.3.5 which states that unbonded tendons should only be used on grade; the engineer needs to take this into account before starting the design.
