Structures Unit Test Review PDF

Structures Study Note Hazel Clark 7/8D Basic structures 1: Structures- something with a definite shape and size Form- the shape of something Function: what something is used for Forms of structures: Solid- one solid piece or solid pieces piled together (ie. Bones)...

Structures Study Note Hazel Clark 7/8D Basic structures 1: Structures- something with a definite shape and size Form- the shape of something Function: what something is used for Forms of structures: Solid- one solid piece or solid pieces piled together (ie. Bones) Frame- framework of connected parts, usually bars or beams (ie. Human body) Shell- a panel or connected panels usually for the purpose of protecting or holding (ie. Turtle) Forces and structures: Force- a push or pull that causes movement or a change in shape they also cause stress on the object Magnitude- size Fatigue- when the structures are weakened Failure- when under extreme stress or fatigue to the point of breaking External forces: -are forces that act from the outside Loads: -Dead loads are anything that places continuous or permanent force to a structure -live loads are forces on a building like people, furniture and vehicles Internal forces: Compression- when the load pushes on the structure, the structure must have the strength to carry the weight of the occupant and their belongings as well as its own weight Tension- is the pulling force, it must have the tensile strength to withstand its load Shear- is the cutting force when different parts of the structure are pressed in different directions Torsion- torsion is the twisting force of moving things in opposite directions Amount of force on an object: Magnitude- is the amount of force applied to the structure (ie. weight) Point of application- the exact location where force is applied to the structure (ie. pressure) Direction- is the line which something moves (ie. angle) Mass: -is the amount of matter in an object -mass is measured in kg,g,lbs -mass doesn’t change regardless of location Weight: -is the force exerted by gravity on an object’s mass -weight is measured in newtons (n) or lbs -weight depends on the mass of the object and then gravitational field its in -location changes the object's mass Structural Efficiency: Mass supported (in grams) Mass of structure (in grams) In easier words The amount of weight the bridge can hold The weight of the bridge Function: -What the structure was made to do -ie. Span a gap, stand up to wind and support cars Shape: -The shape was made so it can withstand the forces -ie. Arch and wired cantilever Material: (is a key part of the building) concrete an iron rods: -concrete is are strong when pushed and iron is strong when pulled Layered materials: -used to create extra strength or take advantage of multiple properties -ie. juice boxes have a leak resistance layer Woven or knit: -are very flexible -ie. Newspaper, cloth Joining technology: -joints are where the pieces in the structure are held together -joints are used to connect different materials -mobile joints are joints that allow movement in a structure -rigid joints prevent movement in a structure​ -joints are the weakest point of the structure and is the reason why there are different types Center of gravity 2: -center of gravity is the middle point of a structure where all the mass is concentrated -stable is a term used to keep a structure in place and unable to move -irregularly shaped objects center of gravity is in the geometric center -regularly shaped objects shift and move therefore the center of gravity changes -the object is only stable only if the center of gravity is directly above the base point of balance Center of gravity (part 3): -the structure stability is where the mass is concentrated -the lower to the ground a structure is more stable / concentrated Orthographic Drawings: -done in pencil -use a ruler -write your name -write your dimensions -use capital letters -drawn to scale Ergonomics: -is the science of designing tools structures and systems that make it easier for humans to interact and use Other definitions: -a truss is a framework consisting of rafters, posts and struts -beams is a long sturdy piece of wood spanning over an open part of a building