man with hands on hips
An axial force is any force that acts directly on the central axis of an object. These forces are usually stretching forces or compression forces, depending on the direction. Also, when the force loading is uniform at the geometric center of the shape, it is concentric, and when it is irregular, it is eccentric. Unlike many acting forces, an axial force is usually its own counterattack; an object pulled or pushed uniformly in opposite directions does not move. The brute force occupies a position similar to the axial force, but operates perpendicular to the central axis of the object.
One of the most important parts of the discussion of axial forces is the idea of a geometric center. This is a point within the boundaries of a solid object that is the perfect center of all mass. In a simple object like a cylinder, it is easy to find the exact center of the object simply by measuring the sides. In a complex object like a bicycle, the process is much more complicated. While there is a very complex series of mathematical equations that will find this point, it is basically the point where the object’s mass is the same in any opposite direction.
In a complex object, this point can be almost anywhere within the larger space of the shape. When looking at an object, the space the object occupies is usually larger than the object itself. Factors such as density and protruding arms can cause the geometric center to exist on the surface or even out of shape.
The central axis of the object goes back and forth through the object. This line is based on the shape of the object, not its mass or density. The central axis may or may not pass through the geometric center.
When a force acts directly on the central axis, it is an axial force. These forces will often compress the shaft from either end or stretch the shaft in two opposite directions; as a result, the object does not normally move. An excellent example of these forces can be seen in the columns inside buildings. The column has an axis that runs through the entire form, from top to bottom. The column is constantly compressed while supporting the frame deck.
In the column example, the axial force passes through the geometric center of the shape; this makes the force concentric. A concentric force is stable at rest. When the axis does not pass through the geometric center, the shape is not stable and the force is eccentric. This generally means that the form cannot resist axial forces while at rest; the structure will not be able to cope with the disproportionate energies acting on it.