These MCQs are designed to test knowledge and understanding of both fundamental principles and advanced concepts in Structural Analysis, making them an essential tool for students and professionals in the field of civil engineering.
1. Euler's critical load formula for a column with pinned ends is given by:
Answer:
Explanation:
Euler's formula for the critical load (buckling load) of a column with pinned ends is P_cr = π²EI/L², where E is the modulus of elasticity, I is the moment of inertia, and L is the effective length of the column.
2. In the moment distribution method, what does a distribution factor represent?
Answer:
Explanation:
In the moment distribution method, the distribution factor is the ratio of the stiffness of a member to the total stiffness at a joint. It represents the proportion of the moment carried by a member.
3. The degree of static indeterminacy of a beam fixed at one end and simply supported at the other is:
Answer:
Explanation:
A beam that is fixed at one end and simply supported at the other end has two degrees of static indeterminacy – one moment reaction and one horizontal reaction at the fixed end.
4. What is the purpose of a shear force diagram (SFD)?
Answer:
Explanation:
A shear force diagram is a graphical representation that shows how the shear force varies along the length of a beam.
5. The deflection of a cantilever beam with a point load at the free end is given by:
Answer:
Explanation:
The deflection at the free end of a cantilever beam with a point load P is given by the formula δ = PL³/3EI, where L is the length of the beam, E is the modulus of elasticity, and I is the moment of inertia.
6. Castigliano's theorem is used to determine:
Answer:
Explanation:
Castigliano's theorem is a method used in structural analysis to determine the deflection and rotation at a point in a structure.
7. In a simply supported beam carrying a uniformly distributed load, the maximum bending moment occurs:
Answer:
Explanation:
For a simply supported beam with a uniformly distributed load, the maximum bending moment occurs at the center of the beam.
8. The slope-deflection method is used to analyze:
Answer:
Explanation:
The slope-deflection method is a structural analysis method for determining the moments and rotations in statically indeterminate beams and frames.
9. The degree of kinematic indeterminacy of a frame structure is calculated as:
Answer:
Explanation:
The degree of kinematic indeterminacy of a frame structure is determined by 3j – r, where j is the number of joints and r is the number of reaction components.
10. In structural analysis, "influence lines" are used to determine:
Answer:
Explanation:
Influence lines are graphical representations used to analyze the effects of moving loads on structures, particularly for determining maximum reactions, shear forces, and bending moments.
11. The conjugate beam method is used to determine:
Answer:
Explanation:
The conjugate beam method is an analysis technique used to find deflections and slopes in beams by transforming the actual beam into a conjugate beam with different boundary conditions.
12. The Macaulay’s method is primarily used for:
Answer:
Explanation:
Macaulay’s method is a technique used to calculate the deflection at any point in a beam, especially useful for beams with varying cross-sections or loading conditions.
13. In the context of structural analysis, "redundant forces" refer to:
Answer:
Explanation:
Redundant forces are additional unknown forces or moments that exist in statically indeterminate structures. They cannot be determined by equilibrium equations alone and require compatibility conditions for their evaluation.
14. The concept of a "plastic hinge" in structural analysis applies to:
Answer:
Explanation:
A plastic hinge refers to a theoretical concept in structural analysis where a point in a beam or frame undergoes plastic deformation under moment, allowing rotation without an increase in moment.
15. For a propped cantilever beam with a point load at the free end, the reaction at the prop is:
Answer:
Explanation:
For a propped cantilever beam with a point load at the free end, the reaction at the prop is half the point load due to the distribution of forces in the beam.
16. The stiffness matrix in structural analysis is used to relate:
Answer:
Explanation:
The stiffness matrix is a fundamental concept in structural analysis that relates nodal displacements to the nodal forces in the structure.
17. The principle of virtual work in structural analysis states that:
Answer:
Explanation:
The principle of virtual work states that for a structure in equilibrium, the total virtual work done by external forces is zero. It is used to determine displacements and rotations in structures.
18. In a truss, the method of sections is used to:
Answer:
Explanation:
The method of sections involves cutting the truss into two parts and using equilibrium equations to calculate internal forces in selected members.
19. The load carrying capacity of a column is affected by its:
Answer:
Explanation:
The load-carrying capacity of a column is influenced by its length, cross-sectional area, and slenderness ratio, which all contribute to its stability and strength.
20. A two-hinged arch is considered statically determinate if:
Answer:
Explanation:
A two-hinged arch is considered statically determinate when there are no horizontal reactions at the hinges,and it can be analyzed using equilibrium equations alone without the need for additional compatibility equations.
21. In the context of structural analysis, the term 'deflected shape' refers to:
Answer:
Explanation:
The 'deflected shape' of a structure refers to the deformed shape it assumes under applied loads, showing how the structure bends or deflects due to these loads.
22. The term 'influence line' in structural analysis is used to represent:
Answer:
Explanation:
Influence lines in structural analysis are graphical representations that depict how a response (such as reaction, shear force, or bending moment) at a specific point on a structure varies as a point load moves across it.
23. The 'consistent deformation method' is a technique used to analyze:
Answer:
Explanation:
The consistent deformation method is used in the analysis of statically indeterminate structures. It involves satisfying both the equilibrium and compatibility conditions by considering the deformations in the structure.
24. The 'column analogy method' in structural analysis is used to:
Answer:
Explanation:
The column analogy method is a technique used to analyze statically indeterminate beams. It draws an analogy between the bending of a beam and the axial deformation of a hypothetical column.
25. In the 'slope deflection method', the primary unknowns are the:
Answer:
Explanation:
The slope deflection method is a displacement method used for analyzing statically indeterminate structures. The primary unknowns in this method are the slopes and deflections at the joints of the structure.
26. If in a pin-jointed plane frame (m + r) > 2j then the frame is:
Answer:
Explanation:
If (m + r) > 2j in a pin-jointed plane frame, it indicates the frame has more members and reactions than necessary for equilibrium, making it statically indeterminate yet stable【76†source】.
27. If in a rigid-jointed space frame (6m + r) < 6j then the frame is:
Answer:
Explanation:
For a rigid-jointed space frame, if (6m + r) < 6j, it indicates that the frame lacks sufficient members or reactions to be stable, leading to an unstable configuration【87†source】.
28. A load 'W' placed at a distance of 0.4L from the left support in a simply supported beam. The maximum bending moment at this position is:
Answer:
Explanation:
The maximum bending moment under a point load on a simply supported beam can be calculated using the formula WL(1-x)/L, where x is the distance from one support. At 0.4L from the left support, the bending moment is 0.24 WL【93†source】.
29. If there are m unknown member forces, r unknown reaction components, and j number of joints, then the degree of static indeterminacy of a pin-jointed plane frame is given by:
Answer:
Explanation:
The degree of static indeterminacy of a pin-jointed plane frame can be calculated as m + r – 2j, where m is the number of members, r is the number of reaction components, and j is the number of joints【112†source】.
30. The carryover factor in a prismatic member whose far end is fixed is:
Answer:
Explanation:
In a prismatic member with a fixed far end, the carryover factor is 1/2. This means that when a moment is applied at one end of the member, half of that moment is transferred (or "carried over") to the far end【113†source】.
31. The degree of kinematic indeterminacy of a pin-jointed space frame is:
Answer:
Explanation:
The degree of kinematic indeterminacy of a pin-jointed space frame is given by 3j – r, where j is the number of joints and r is the number of reaction components. This accounts for the three possible directions of movement at each joint【115†source】.
32. The maximum bending moment due to a train of wheel loads on a simply supported girder:
Answer:
Explanation:
The maximum bending moment in a simply supported girder due to a train of wheel loads typically occurs under one of the wheel loads. This is where the applied load creates the greatest bending stress【116†source】.
33. The number of unknown internal forces in each member of a rigid-jointed plane frame is:
Answer:
Explanation:
In each member of a rigid-jointed plane frame, there are three unknown internal forces. These typically include two moments and one shear force at each end of the member【120†source】.
34. The number of independent equations to be satisfied for static equilibrium in a space structure is:
Answer:
Explanation:
For static equilibrium in a space structure, six independent equations need to be satisfied. These include three equations for force balance in three dimensions and three for moment balance about three axes【121†source】.
35. A simply supported beam deflects by 5 mm when it is subjected to a concentrated load of 10 kN at its center. What will be the deflection in a 1/10 model of the beam if the model is subjected to a 1 kN load at its center?
Answer:
Explanation:
The deflection in the scaled model of the beam will be the same as the original beam if the scale factor for load and dimensions is maintained. In this case, the deflection remains 5 mm【122†source】.
36. A pin-jointed plane frame is unstable if:
Answer:
Explanation:
A pin-jointed plane frame is considered unstable if the sum of the number of members (m) and reaction components (r) is less than twice the number of joints (2j)【123†source】.
37. Degree of static indeterminacy of a rigid-jointed plane frame having 15 members, 3 reaction components, and 14 joints is:
Answer:
Explanation:
The degree of static indeterminacy can be calculated using the formula: Degree of indeterminacy = m + r – 3j. For this frame, it is 15 + 3 – 3*14 = 6【124†source】.
38. The degree of static indeterminacy up to which column analogy method can be used is:
Answer:
Explanation:
The column analogy method is typically used for analyzing structures with a degree of static indeterminacy up to 3. Beyond this, the method becomes increasingly complex and less practical【125†source】.