Topic 4 – Forces, Loads and Stresses

Forces External Forces are stresses that act on a structure from outside the structure. These in turn cause INTERNAL FORCES that can damage the structure.

External forces Dead loads do not change Example: walls, floors, roofs, ceilings, stairways… Live loads Can change Example: Wind, rain, earthquakes, tides, floods, snow..

Internal Forces There are a bunch of forces…. Tension  Pulling force Tensile Strength- Measures the largest tension force the material can withstand before breaking Compression  Squishing force Compressive Strength Shear  Tearing force Shear Strength Torsion  Twisting Torsion Strength

Draw these in your book and Label

LAB!! Examining Forces…. Investigation 4D on page 310.