Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. National Exams, December 2016 — 07-Str-A1 Elementary Structural Analysis, 3 hours, CLOSED BOOK (an approved Sharp or Casio calculator is permitted). Six questions constitute a complete paper: Questions 1–5 are compulsory and one only of Questions 6, 7 or 8 is attempted, for 100 marks (6 + 18 + 18 + 20 + 18 + 20). Marks are shown in the left margin. All eight questions are worked below, because the three alternatives exercise three quite different methods — three-hinged-frame statics, influence lines and virtual work — and the complete set is the more useful study resource.
Every structure on this paper is defined by a hand-drawn figure and nothing else: the printed text states the task, the drawing carries the geometry, the loads and the support types.
Sign conventions used throughout. Shear force is positive when the resultant of the forces to the left of a section acts upwards along the positive local normal of the member; bending moment is positive when it sags the member (tension on the underside), and sagging ordinates are plotted above the axis in every diagram. Truss member forces are quoted as T for tension and C for compression. In the slope-deflection work of Question 5 the member-end moments follow the usual convention, clockwise on the member end taken as positive, so that the sagging moment is $+M_{ij}$ at the left end of a member and $-M_{ji}$ at its right end.
Reference texts.
