Stress in beams

• If a material (beam) is subjected to a force, an equal force acts in the opposite direction
• This force is known as reaction
• This results in forces being set up inside the material(beam)

Forces and reaction. i) A load resting on the ground. ii)A balanced lever

• These internal forces are known as stresses
• stress-forces that occur inside a material as a result of forces acting within it
• There are three types of stress
• Tensile stresses-is a result of stretching forces.
• They are created by forces trying to pull the material apart
• compressive stresses-are a result of forces acting in opposite direction with one another creating a squashing effect.
• They are produced by forces trying to compress material
• shear stresses- these are also known as twisting forces
• they are produced by equal and opposite forces which are not in line.
• They tend to make one part of the material slide over one another.

Load and shape

• when a load is applied to a material
• Stresses are produced
• Most times there is also a change of shape especially if the material is not rigid

To access more topics go to the Combined Science Notes page.