Timoshenko beam–column buckling. Does Dario stand the test?

In the paper [Aristizabal-Ochoa JD. Slope–deflection equations for stability and second-order analysis of Timoshenko beam–column structures with semi-rigid connections. Eng Struct 2008;30(9)] the Haringx stability theory is chosen. In the present paper it is shown that this theory yields a wrong limit value for very weak-in-shear buckled beam–columns. The theory is derailing seriously in a very unsafe manner. The failure is shown in three ways, first by considering the case of an ideal weak-in-shear beam–column, next by reasoning arguments and finally by referring to older studies. It has not been sufficiently recognized that Haringx studied the lateral buckling of helical springs, and did not consider the critical buckling load for extremely shear-weak structural members. His theory appears to be reliable for helical springs, but is inadequate for shear-weak beam–columns. Results in several beam–column papers by Dario were obtained on the basis of the Haringx theory and, therefore, must be used with utmost care, if not extremely distrusted.