The authors thank the discussers for their interest in the paper, and for their discussion, as it provides the opportunity to point out a number of incorrect statements in the literature such as those repeated by the discussers. The discussers state that the longitudinal normal strain expression (1) "may lead to incorrect prediction of nonlinear behavior of frames when the twist rotation of the cross section of the members is not infinitesimally small (sic)." The discussers then show alternative expression (1), which is said to lead to energy Eq. (3). This argument was originally made by Pi and Trahair and was repeated in a more recent version (Pi and Bradford 1999a, 2001). Pi and Bradford (1999a, 2001) claimed that other researchers used the strain expression (1) and subsequently added the virtual work terms due to bending shear forces "more by engineering judgment rather than by a rigorous mechanical (sic) derivation." This is an unjustified claim, as explained in the following paragraph.
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