Moment‐Rotation Functions For Steel Connections

A least‐squares curve‐fitting procedure is shown to provide better accuracy than the previously used method of selected points when fitting Richard‐Abbott and Ramberg‐Osgood functions to experimental moment‐rotation data. Comparisons are presented to show that the Richard‐Abbott function, in dimensionless form, provides fits that are comparable to cubic B‐spline fits and more accurate than Ramberg‐Osgood function fits for common connection types. A multiple‐regression analysis procedure is described that employs the Richard‐Abbott function to derive a standardized connection moment‐rotation function. Its advantage over previously used standardization procedures is that it is able to utilize all available experimental data in the derivation of the standardized function. The latter function is expressed in terms of the geometric parameters for the connection type considered.