1. Compressive strength in lacing bars in single lacing system is equal to
a) Vt /(N secΘ)
b) Vt /(N cosecΘ)
c) Vt N cosecΘ
d) (Vt /N) cosecΘ
Explanation: Compressive strength in lacing bars is equal to (Vt /N) cosecΘ for single lacing system and (Vt/2N) cosecΘ for double lacing system, where N = number of shear resisting elements.
2. Minimum radius of gyration for lacing flats is
a) t/√12
b) t/12
c) t/√24
d) t/24
Explanation: Minimum radius of gyration for lacing flats is t/√12 , where t is thickness of flat.
3. The load on rivet/bolt when two lacing flats are connected at same point is
a) (Vt / N) cotΘ
b) 2(Vt / N) cotΘ
c) 2Vt N cotΘ
d) Vt NcotΘ
Explanation: Strength of bolt /rivet should be greater than load coming over rivet/bolt. The load on rivet/bolt when two lacing flats are connected at same point is 2(Vt/N)cotΘ.
4. The load on rivet/bolt when two lacing flats are connected at different point is
a) (Vt / N) cotΘ
b) 2(Vt / N) cotΘ
c) 2Vt N cotΘ
d) Vt NcotΘ
Explanation: Strength of bolt /rivet should be greater than load coming over rivet/bolt. The load on rivet/bolt when two lacing flats are connected at different point is (Vt/ N) cotΘ.
5. Which of the following statement is true?
a) Number of battens in a column should be such that member is divided into not less than three bays
b) Number of battens in a column should be such that member is divided into less than three bays
c) Number of battens in a column should be such that member is divided into less than two bays
d) No restriction on number of battens
Explanation: Battens are plates or any other rolled section used to connect the main components of compression members. Battens should be placed opposite to each other on the two parallel faces of compression members. Number of battens in a column should be such that member is divided into not less than three bays.
6. Battens should be designed to resist transverse shear force which is
a) 5% of axial force
b) 0.5% of axial force
c) 2.5% of axial force
d) 7.2% of axial force
Explanation: Battens should be designed to resist transverse shear force which is 2.5% of total axial force on whole compression member. This transverse shear force is divided equally in all parallel planes in which, there is shear resisting elements.
7. Battens should be designed to resist longitudinal shear equal to
a) Vt L0 ns
b) Vt L0 / ns
c) Vt /L0 ns
d) Vt L0n/s
Explanation: Battens should be designed to resist longitudinal shear equal to V = Vt L0 / ns , where Vt is transverse shear force, L0 is distance between centre-to-centre of battens longitudinally, s is minimum transverse distance between centroids of bolt/rivet group/ welding connecting batten to main member, n is number of parallel planes of battens.
8. Battens should be designed to resist moment equal to
a) Vt L0 n
b) Vt L0 / n
c) Vt /L0 n
d) Vt L0 /2n
Explanation: Battens should be designed to resist moment equal to Vt L0/2n , where Vt = transverse shear force, L0 = distance between centre-to-centre of battens longitudinally, n = number of parallel planes of battens.
9. Which of the following is true about effective depth of battens?
a) less than perpendicular distance between centroids for end battens
b) less than three quarters of the perpendicular distance between centroids for intermediate battens
c) not less than twice the width of one member in plane of batten
d) less than twice the width of one member in plane of batten
Explanation: When plates are used for battens, effective depth between end bolts/rivets or welds should not be less than twice the width of one member in plane of batten, not less than perpendicular distance between centroids for end battens and not less than three quarters of the perpendicular distance between centroids for intermediate battens.
10. Thickness of batten plates shall be
a) not less than 1/50th of distance between innermost connecting transverse bolts/rivets
b) less than 1/50th of distance between innermost connecting transverse bolts/rivets
c) less than 1/60th of distance between innermost connecting transverse bolts/rivets
d) less than 1/80th of distance between innermost connecting transverse bolts/rivets
Explanation: Thickness of batten plates shall be not less than 1/50th of distance between innermost connecting transverse bolts/rivets or welds perpendicular to main member i.e. t > (1/50)(s + 2g), where g is gauge distance for particular section.