“…Thus, the influence of shear lag phenomenon due to both flexure and torsion, which is not constant along the beam length, should also be considered for curved geometries. The early curved-beam models that have been formulated are either restricted to the analysis of only the beam behavior in the plane of curvature [9] or do not take into account secondary shear deformation effect caused by nonuniform warping [8,10], while other efforts consider only doubly symmetric cross sections [11]. In general, even in recent or past years, although the planar problem has been extensively studied, comparatively little work has been done concerning the general three dimensional, non-planar, or coupled lateral-torsional response of curved beams [9,[11][12][13][14].…”