Force Analysis

Abstract

In this chapter, we will learn how to perform the force analysis. First, the concept of constraint and reactive force is introduced, and then the steps on force analysis are given.

Exercises

• 3.1 Perform the force analysis about the slender bar AB without gravity, and the analysis on the disk with mass m, as shown in Fig. 3.23. The bar is fixed by a rope at point C, and the disk contacts with the bar at points D and E. The contact surfaces are both smooth.

  Fig. 3.23

  

  One bar and one disk

• 3.2 In Fig. 3.24, please perform the force analysis about the bar AB, which contacts with a ball at point C. The contact surfaces and points are all smooth.

  Fig. 3.24

  

  One bar contacting with one disk

• 3.3 A cantilever is clamped at point A, where a couple m and a uniformly distributed force q are applied on the beam, as shown in Fig. 3.25. Please perform the force analysis on the beam.

  Fig. 3.25

  

  One cantilever

• 3.4 As shown in Fig. 3.26, there is one bar AD hinged with one disk without weight. Point B and C are both hinged points. A concentrated force is applied at point D. Please make force analysis on the bar and the disk.

  Fig. 3.26

  

  One bar hinged with one disk without weight

• 3.5 As shown in Fig. 3.27, a bar is lying on a wall corner, linked by one rope BD. A concentrated force F is applied at point E on the bar. The contact surfaces are smooth. Please make the force analysis on the bar.

  Fig. 3.27

  

  A bar lying at a wall corner

• 3.6 As shown in Fig. 3.28, a system includes three bars, i.e., AB, CD, and BE. A horizontal force F is applied at point A. Please perform the force analyses for all of these bars.

  Fig. 3.28

  

  A system including three bars

Answers:

3.1

3.2

3.3

3.4

3.5

3.6