Flexural-torsional buckling of shear deformable steel circular arches under a central concentrated load in a thermal environment

When subjected to a constant temperature gradient, a steel circular arch will experiences non-uniform thermal expansion in its axial direction. This expansion will produces complex internal forces in the arch, which in turn will affect its flexural-torsional buckling behavior under a central concentrated radial load. Hitherto, research studies of the flexural-torsional buckling of such arches are scarce. The position of the effective centroid and shear center do not coincide with the geometric centroid of the section in a temperature gradient field, and this influences the flexural-torsional buckling response. In this paper, the flexural-torsional buckling of shear deformable circular arches with in-plane elastic rotational end restraints subjected to a central concentrated radial load at a constant temperature gradient field is studied. The theoretical solutions for the buckling load of the arch including the effect of the temperature gradient field are obtained and validated by ANSYS simulations. It is found that the buckling load decreases with an increase of the temperature differential when the included angle is small and increases with an increase of the temperature differential in case the included angle is larger than a certain value. The buckling loads including shear deformations are higher than those ignoring shear deformations at a bigger temperature differential. The influences of shear deformations on the buckling load are more significant at a bigger temperature differential.