Applied Mechanics

Applied Mechanics or Engineering Mechanics is considered as the backbone of all engineering programs. It deals with the basic concepts of force, moment  and its effects on the bodies at rest or in motion. It helps to understand how different bodies behave under the application of different types of loads.

Mechanics can be broadly divided into two branches; Statics and Dynamics. Statics deals with the bodies at rest whereas dynamics involves studies related to bodies in motion. It can also be divided as mechanics of rigid bodies and mechanics of deformable bodies. Good knowledge of material properties is also essential for studying mechanics of deformable bodies. 

Applied mechanics provides the basis for further studies in Structural Analysis which are required for structural design of different components of buildings or bridges. A good knowledge of support reactions is also important to understand the behaviour  of structures.

Static equilibrium

A structures can be in static equilibrium if the following conditions are met;

1. For a 3-dimensional structure ( space structure), equilibrium requirement is  force and moment balance along three independent (perpendicular) axes.

  ΣFx = 0,    ΣFy = 0,   ΣFz = 0,

  ΣMx = 0,   ΣMy = 0,   ΣMz = 0,

2. For a 2-dimensional structure ( planar structure)), equilibrium requirement is force balance along two perpendicular axes (in the plane) and moment balance about an axis perpendicular to the plane.

  ΣFx = 0,  ΣFy = 0,  ΣMz = 0,

The above conditions of static equilibrium can be used to find the support reactions.

Free-body diagrams, which show all the reactions and applied loads on the body are required to be drawn before applying the equations of static equilibrium.

Solved examples on application of equilibrium equations for calculation of support reactions (Problem 4-1,  Problem 4-2), Truss member forces by method of joints (Problem 3-1), method of sections (Problem 3-2). and other solved examples

Do you know what is shearing force and bending moment?

What is indeterminate structure?