Frames:

The frames have members such as trusses. In trusses, loads act only at the joints. These forces which act at the ends of the members produce compression or tension in them along their axes. In frames loads can act at the joints and also along the length of the members to cause bending action in the members. As a result, a section through such a member will disclose that the member is subjected to unknown axial force along with an unknown transverse force. The transverse force shall result in bending moment whose magnitude will vary with the location of section.