Design of Steel Structures Multiple Choice Questions on “Design Considerations, Analysis & Methods”.
1. Which of the following is correct criteria to be considered while designing?
a) Structure should be aesthetically pleasing but structurally unsafe
b) Structure should be cheap in cost even though it may be structurally unsafe
c) Structure should be structurally safe but less durable
d) Structure should be adequately safe, should have adequate serviceability
Answer: d
Clarification: Structure should be designed such that it fulfils it intended purpose during its lifetime and be adequately safe in terms of strength, stability and structural integrity and have adequate serviceability. Structure should also be economically viable, aesthetically pleasing and environment friendly.
2. What is serviceability?
a) It refers to condition when structure is not usable
b) It refers to services offered in the structure
c) It means that the structure should perform satisfactorily under different loads, without discomfort to user
d) It means that structure should be economically viable
Answer: c
Clarification: Serviceability is related to utility of structure. The structure should perform satisfactorily under service loads, without discomfort to user due to excessive deflection, cracking, vibration, etc. Other considerations of serviceability are durability, impermeability, acoustic and thermal insulation etc.
3. Analysis is referred to _____________
a) determination of cost of structure
b) determination of axial forces, bending moment, shear force etc.
c) determination of factor of safety
d) drafting architectural plans and drawings
Answer: b
Clarification: Analysis refers to determination of axial forces, bending moment, shear force, torsional moments etc. acting on different members of structure due to applied loads and their combinations.
4. The structure is statically indeterminate when________________
a) static equilibrium equations are insufficient for determining internal forces and reactions on that structure
b) static equilibrium equations are sufficient for determining internal forces and reactions on that structure
c) structure is economically viable
d) structure is environment friendly
Answer: a
Clarification: When the static equilibrium equations are insufficient for determining internal forces and reactions on that structure, the structure is said to be statically indeterminate. Analysis of these structures is complex and cannot be analysed only by using laws of statics, various analytical methods like slope deflection method, moment distribution method, etc.
5. Which of the following is one of the methods of analysis prescribed in the code for steel structures?
a) Hinge Analysis
b) Limit Analysis
c) Roller Analysis
d) Dynamic Analysis
Answer: d
Clarification: Code suggests the use of any of the following methods for steel structures : (i) elastic analysis, (ii) plastic analysis, (iii) advanced analysis, (iv) dynamic analysis.
6. Which method is mainly adopted for design of steel structures as per IS code?
a) Limit State Method
b) Working Stress Method
c) Ultimate Load Method
d) Earthquake Load Method
Answer: a
Clarification: Steel structures and their elements are normally designed by limit state method. When limit state method cannot be conveniently adopted, working stress method may be used.
7. Which IS code is used for general construction of steel?
a) IS 456
b) IS 256
c) IS 800
d) IS 100
Answer: c
Clarification: IS 800:2007 is the code of practice for general construction in steel. It is issued by Bureau of Indian Standards.
8. Which of the following relation is correct?
a) Permissible Stress = Yield Stress x Factor of Safety
b) Permissible Stress = Yield Stress / Factor of Safety
c) Yield Stress = Permissible Stress / Factor of Safety
d) Permissible Stress = Yield Stress – Factor of Safety
Answer: b
Clarification: Permissible Stress = Yield Stress / Factor of Safety. Permissible Stress is the amount of stress that will not cause failure. It is a fraction of yield stress. It takes care of overload or other unknown factors.
9. In Working Stress Method, which of the following relation is correct?
a) Working Stress ≤ Permissible Stress
b) Working Stress ≥ Permissible Stress
c) Working Stress = Permissible Stress
d) Working Stress > Permissible Stress
Answer: a
Clarification: In Working Stress Method, Working Stress ≤ Permissible Stress. Each member is checked for number of different combinations of loadings.
10. Arrange the following in ascending order according to their factor of safety in working stress method :
(i) tension members, (ii) long column, (iii) short column, (iv) connections
a) i < ii < iii < iv
b) i < iv < ii < iii
c) i = iii < ii < iv
d) iv = i < iii < ii
Answer: c
Clarification: In working stress method, the factor of safety for the above are as follows : (i) for tension members = 1.67, (ii) for long column = 1.92, (iii) for short columns = 1.67, (iv) for connections = 2.5-3.
11. What is Load Factor?
a) ratio of working load to ultimate load
b) product of working load and ultimate load
c) product of working load and factor of safety
d) ratio of ultimate load to working load