Introduction and Background
Theory
Definition of a Beam
Members that are slender and support loadings that are applied perpendicular to their longitudinal axis are called beams. Beams are important structural and mechanical elements in engineering. Beams are in general, long straight bars having a constant cross-sectional area, often classified as to how they are supported. For example, a simply supported beam is pinned at one end and roller-supported at the other, a cantilevered beam is fixed at one end and free at the other, and an overhanging beam has one or both of its ends freely extended over the supports.
Figure 1: Types of beams
Types of Internal Loading
The design of a structural member, such as a beam, requires an investigation of the forces acting within the member which is necessary to balance the force acting externally on it. There are generally four types of internal loading that can be resisted by a structural member:
Figure 2: Types of Loadings
A. Normal Force, N
This force acts along the member’s longitudinal axis and passes through the centroid or geometric centre of the cross-sectional area. It acts perpendicular to the area and is developed whenever the external loads tend to push or pull on the two segments of the body.
B. Shear Force, V
If the external force is applied perpendicular to the axis of a member, it causes an internal stress contribution acting tangent to the member’s cross section. The resultant of this stress distribution is called the ‘shear force’. The shear force is developed when the external loads tend to cause the two segments of the body to slide over one another.
C. Bending Moment, M
When external moment is applied perpendicular to the axis of a member, the internal distribution of stress is
References: 1. Watts, Cedric. William Shakespeare: Othello. London: Wordsworth Classics, 1995. 2. Johnsen-Neshati, Kristin. “A Cultural Context for Othello.” Othello 2005-2006 Season . Wasington DC: Shakespeare Theather Company, 2005. Online: 18 March 2007 <http://www.shakespearetheatre.org/plays /articles.aspx?&id=83>. 3. The Literature Network. “Othello” The Literature Network. Online: 18 March 2007 <http://www.online-literature.com/shakespeare/othello/> 4. Richard Dutton and Jean E. Howard. A Companion To: Shakespeare’s Works (The Tragedies). Volume 1. United Kingdom: Blackwell Publishing, 2003.