This set of Structural Analysis Multiple Choice Questions & Answers (MCQs) focuses on “Qualitative Influence Lines”.
1. If we require to construct ILD of vertical support at a pin joint, then according to Muller-Breslau principle, by which type of support should it be replaced?
a) Roller guide
b) Pin roller
c) Fixed support
Explanation: We need to remove the force for which we need to construct ILD and roller guide would remove the vertical reaction.
2. For ILD of shear at a point just left to C, what will be the equation for it on BC part of beam?
Explanation: On applying Muller-Breslau principle, we will see that the part right to the point can’t move as point C is right next to it. So, ILD will have to remain parallel to x axis.
3. If we draw ILD of shear at appoint just right to point C, then what will be its slope at BC part of beam?
Explanation: Slope of ILD in part CD of beam will be -0.5 as initially it will be at 1 and finally at 0. Now, due to Muller-Breslau principle, both lines will be parallel.
4. If we draw ILD for shear at a point E (lying in between points C & D), then at how many points would his curve attain its peak?
Explanation: At E, value will be +0.5 and since slope of two lines will be parallel, value of ILD at B too will be 0.5.
5. What will be the lowest point of ILD curve for moment at a point just left to point C?
Explanation: For moment, we rotate it by 1 rad. So, min. point will be -2 at hinge B as after that the curve will change its slope.
6. What will be the equation for ILD of vertical reaction at point A for AB part of beam?
Explanation: Since, point A is a fixed support, ILD will be parallel to x axis.
7. What will be the maximum point of ILD of vertical reaction at point C?
Explanation: It will be 1 at point C and will be 2 at point D after which it will change its slope as D is a hinge.
8. What will be the area under the ILD curve if we make it for the vertical reaction at a point just left to point C?
Explanation: It will be a triangle with base 2m and height 1 for CE and triangle with base 1 and height 1 for BC. It will be 0 for AB as A is a fixed support.
9. What will be the area under the ILD curve if we make it for the vertical reaction at a point just right to point C?
Explanation: It will be a triangle with 1*1 dimension for CD and a triangle with base 1 and height 1 for DE. It will be 0 for rest of the beam.
Sanfoundry Global Education & Learning Series – Structural Analysis.
To practice all areas of Structural Analysis, here is complete set of 1000+ Multiple Choice Questions and Answers.