Classifying Structures Flashcards
Structure
An object with a definite size, shape and function. To the cellular level
What can all structures be classified by
Natural or manufactured
Natural
Not built by people
Living or non-living
Rocks, trees
Manufactured
Built by people
Modeled after natural structures
Velcro, umbrella
What can natural and manufactured structuresbe classified as?
Mass, frame and shell
Mass structure
Piling up or forming similiar materials into a shape
Heavy and use lots of materials (disadvantage)
Parts are held in place by their own weight-hard to break (advantage)
Snow, brick, mountain
Frame structure
Have a skeleton of strong materials which supports the weight
Easy to design (advantage)
Mjst use fasteners, anchors, joints (disadvantage)
Inexpensive (advantage)
Chair, house, bridge, our bones
Shell structure
Strong and hollow
Thin carefully shaped outer layer to provide strength and rigidity
Spreads forces over entire structure so each part shares the load (advantage)
Assembly is tricky (disadvantage)
Egg, box, igloo (not a house)
Composite/Complex structure
Made of a combination of mass, frame or shell structures
Tent, House, Us
What are some manufactured structures that were inspired by natural structures
Bird wings: Hang glider/ Airplane Frogs feet: Scuba fins Turtle shell: Army helmet Rabbit rear legs: Snow Shoes Human arm: Robotic arm Fish body shape: Submarine Beaver dam: Log Shelter
Advantages of mass structure
Strong
Stable
Easy to design and build
Held in place by own weight
Disadvantages of mass structure
Heavy
Use lots of materials
Difficult to move or break apart
What are the advantages of frame struc
Strong skeletons
Contain empty spaces
Easy to design and build
Lightweight (less materials)
What are the disadvantages of frame structure
Joints can weaken
Fasteners may weaken over time
Advantages of shell structure
Thin outer layer is strong and rigid
Spreads forces pver entire structure
Hollow inside
Lightweight
