1.Which of Newton’s three laws of motion is most applicable in structural technology? Why? 2.Sketch an example of each of the four types of structural forces. April 28, 2010 DRILL U3j – L2 Law #3: Action / Reaction The supports, containers, shelters, connectors, and functional shapes all counteract loads on them and the materials contained within.

U3j – L2 Structural Technology Is the force against these objects a pulling force or a pushing force? Which is a tension structure and which is a compression structure TENSION STRUCTURE COMPRESSION STRUCTURE PULLING FORCE PUSHING FORCE

Strength of a construction material is the capacity to support loads by resisting the 4 structural forces. Strength depends on materials’: –Type –Size –Shape –Placement Strength of Materials U3j – L2

U3j - L1 Structural Forces A structure must contend with two types of loads: 1.Dead Loads: permanent loads that do not change. The weight of building materials and permanently installed components: Lumber, brick, glass, nails, steel beams, concrete 2.Live Loads: the weight of all moveable objects, such as people and furniture in a house, vehicles on a bridge. Includes weight of snow, ice, dead leaves, and force of winds. The total weight or mass of all live and dead loads is the Total Load.

Structural Forces A building supports the following loads in the middle of winter: 10,000 lbs of lumber 1000 lbs. of snow and ice 40,000 lbs of brick 300 lbs of wind 600 lbs of glass 200 lbs of nails 1.Calculate the Live Load. 2.Calculate the Dead Load. U3j - L1 Live Load: 1000 lbs lbs. 1,300 lbs. Dead Load: 10,000 lbs. 40,000 lbs. 600 lbs lbs. 50,800 lbs.

Structural Forces 1.Live Load = 1,300 lbs. 2.Dead Load = 50,800 lbs. 3.Calculate the Total Load: Total Load = Live + Dead Load = 1,300 lbs. + 50,800 lbs. Total Load = 52,100 lbs. U3j - L1

Research Project Select one engineering structural failure. For that failure address the following: –Where the structure was built –Purpose of the structure –How the structure failed –Who was responsible for the construction of the structure –Who took the blame for the failure –How many people were injured or killed U3j - L1

1.Work on your Research Project and Presentation with partner 2.Rough draft sketch of poster /power point and information due Tuesday!! U3j - L1

Beams are horizontal structural members Posts are vertical structural members Wood and stone beams have been used for bridges, boats, and roofs since ancient times. Beams and Posts POST BEAM

U3j – L2 Strength of beam –Type –Size (depth of beam) –Shape –Placement How do type, size, and shape affect the strength of these materials? Beams and Posts

U3j - L1 Trusses – an assemblage of beams forming a rigid framework Benefits over beams: –Lighter –More resistant to shear Strength comes from triangular shape Trusses

U3j – L2 Goal: make a truss as light as possible without making it too flexible and unstable. Trusses

U3j – L2