MODEL QUESTION PAPER. B.E. / B. Tech. DEGREE EXAMINATION, APRIL / MAY 2004 Sixth Semester Civil Engineering CE336 STRUCTURAL ANALYSIS II

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1 MOEL QUESTION PPER.E. /. Tech. EGREE EXMINTION, PRIL / MY 2004 Sixth Semester ivil Engineering E336 STRUTURL NLYSIS II Time: Three hurs Maximum: 100 Marks Questins 1 t 10 carry 2 marks each. Questins 11 t 15 carry 16 marks each. Make all sketches in pencil nly. 1. In Fig. 1, is the mid pint f. If a pint lad travels frm t alng the span where and what will be the maximum negative bending mment in. l l/3 Fig In Fig. 1 abve, find the psitin and value f maximum negative shear. 3. Fr the beam in Fig. 1, sketch the influence line fr reactin at and mark the rdinates. 4. Sketch qualitatively the influence line fr shear at fr the beam in Fig. 2. (Yur sketch shall clearly distinguish between straight lines and curved lines) l 1.6 l 0.8 l Fig Fr the structure in Fig. 3, find the net bending mment at. 30 kn 16m Fig. 3

2 6. trestle is pinined n ball and scket jints at the ndes f an equilateral triangle f side a at grund level. The 3 inclined members are a m lng similarly cnnected at tp. Find the vertical cmpnent f cmpressin in each member due t a vertical lad f 1.2 kn hanging frm the apex. 7. Fig. 4 shws the plan f a beam. Find the trsin at due t a dwnward udl f 0.8kN/m ver. (Shw the trque vectr at ) 6m Fig is a cable ver a 48m span. The supprts are at different levels as shwn in Fig. 5. Find l 2. l 2 9m 48m Fig etermine the equal area axis f the sectin shwn in Fig. 6. hen will this be the neutral axis f the sectin? Fig. 6

3 10. mment n the behaviur f the structure in Fig. 3, when a plastic hinge develps at. 11. nsider a simply supprted girder f span l. hen a unifrmly distributed lad f w per unit length lnger than the span crsses the girder frm left t right, cnstruct (i) (ii) the maximum shear frce diagrams the maximum bending mment diagram Indicate rdinates at any distance x frm. 12. nswer either (a) r (b) (a) beam is supprted at, and as shwn in Fig. 7. It has the hinge at. raw the influence lines fr (1) reactins at, and (2) shear t the right f (3) bending mment at E E 8m Fig. 7 (b) etermine the influence line rdinates at any sectin X n f the cntinuus beam shwn in Fig. 8, fr reactin at. X x Fig nswer either (a) r (b) (a) parablic 3 hinged arch shwn in fig. 9 carries lads as indicated. etermine (i) resultant reactins at the 2 supprts (7) (ii) bending mment, shear (radial) and nrmal thrust at, frm. (3+3+3)

4 30 kn 25 kn/m 20 kn 20m Fig. 9 (b) 3 hinged parablic arch has a hrizntal span f 30m and a central rise f. pint f 10 kn mves ver the span. (i) Plt the influence line fr bending mment at a pint 8m frm left supprt. (6) (ii) Find the maximum psitive & negative bending mments at this sectin. (4) (iii) Sketch the abslute maximum bending mment diagrams and shw the peak rdinates and their psitins. (6) 14. nswer either (a) r (b) (a) suspensin bridge with a 2 hinged stiffening girder (fig. 10) has a span f 120m. It has a central dip f 18m. live lad f 12 kn/m is n the bridge a shwn. Find (i) the hrizntal pull at and, due t the live lad. (assume that the strain energy cntributin f the cable is negligible). Take EI f the girder as 16 x 10 5 knm 2. (13) (ii) hat is the purpse served by the stiffening girder? es it really stiffen the cable? (3)

5 120m 18m 25 kn/m 30m 60m Fig. 10 (b) Using the methd f tensin cefficients determine the frces in the members f a 6 member tetrahedral space frame cnfrming t the data in Table 1 belw: N. Nde -rdinates (m) X Y Z t nde (the apex) a dwnward frce f 75 kn acts in the Z directin and a frce f 5 kn acts in the X directin. The grund supprts are designed t develp the fllwing reactins nly. pint Reactin directins Y, Z X, Z Y, Z (i) Find the 6 reactins (10) (ii) Find the 6 member frces (6)

6 15. nswer either (a) r (b) (a) curved beam in the frm f a quadrant f a circle is fixed at and free at (fig. 11). It carries a dwnward lad f at the free and (i) Find the fllwing values fr a sectin X, at an angular distance θ frm O. i. (a) Shear frce (2) i. (b) ending mment (2) i. (c) Twisting mment (4) (ii) Find the deflectin at (8) R E,I,G,I x O 90 0 θ R Fig. 11 (b) n R prtal frame is tested in the lab under 2 cncentrated lads, increasing steadily due t a hydraulic lading system. t any given pint f time the 2 lads are f equal magnitude. If Mp=160 kn/m fr all members, (i) Find the value f at which the prtal wuld cllapse under each f the mechanisms shwn in fig. 12. (3 x 4) (ii) hat will be the mst likely cllapse lad? (4)

7 (a) (b) (c) (d) Fig. 12