07-Str-A1: December 2013

Paper format. National Examinations, December 2013 — 07-Str-A1 Elementary Structural Analysis. Three hours, CLOSED BOOK, an approved Sharp or Casio calculator permitted. Six questions constitute a complete paper: candidates answer ALL of Questions 1 to 5 and ONE of Questions 6, 7 or 8. Marks are shown in the left margin (6 + 18 + 18 + 18 + 20 + 20 = 100). All eight questions are solved below, because the three alternatives test different topics and the whole set is useful for study.

Reference texts.

• R. C. Hibbeler, Structural Analysis, 10th ed. — Ch. 2 (determinacy and stability), Ch. 3 to 5 (trusses, internal loadings, frames), Ch. 6 (influence lines), Ch. 8 to 9 (deflections and virtual work), Ch. 11 to 12 (slope-deflection and moment distribution).
• A. Kassimali, Structural Analysis, 6th ed. — Ch. 3 (equilibrium and determinacy), Ch. 4 (plane trusses), Ch. 5 (beams and frames), Ch. 7 (deflections by virtual work), Ch. 8 (influence lines), Ch. 16 to 17 (slope-deflection and moment distribution).
• K. Leet, C.-M. Uang and A. Gilbert, Fundamentals of Structural Analysis, 5th ed. — a parallel treatment of the same syllabus.
• C. H. Norris, J. B. Wilbur and S. Utku, Elementary Structural Analysis, 4th ed. — the classical text after which this exam code is named.
• Canadian design context: CSA S16 Design of Steel Structures, CSA A23.3 Design of Concrete Structures and the National Building Code of Canada. This is an analysis paper, so no code clause is needed to answer it, but every result below is expressed in the SI units those documents use.

Sign conventions used throughout. For beams and for each individual frame member, shear is positive when the resultant of the forces to the left of (or below) a section acts upward, and bending moment is positive when it sags the member, that is when it puts the underside of a beam or the inside face of a frame member in tension. Member end moments in the slope-deflection work of Question 5 are clockwise-positive on the member, which is the usual convention for that method. Truss forces are quoted as tension or compression rather than by sign. Reactions are drawn in blue and applied loads in red on every figure.

A note on reading this paper. The figures are hand drawn and carry no dimensions that are not on the drawings, so the geometry of every structure below was read from the support symbols one at a time. Two readings materially affect the answers and are flagged where they arise: the plane on which the roller of Question 2(c) bears, and the position of the 50 kN load in Question 8.