by Cher Ko 13 years ago
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Force that changes magnitude , position and direction on a structure
Force that has a constant magnitude , position and direction on or within a structure
shells
Defination of natural shells
Do not have frame
The skin itself provides strength and rigidity
Bird Nest
Honeycomb
Crab Shell
defination of natural frames
Leaf
Spider Web
Trees
Animal Skeleton
non-man made formed by nature
able to absorb small knocks and bumps
cardboard boxes
Drink Carton
safety helmet
Folded or shaped to make storage containers
tanks for liquids such as oil
spanning between two points to withstand loads
Other loads
Tables
Bed
Chairs
Own load
Vehicles
Made by man: factory made
Not natural.
Shells
Defination of man-made shells
The shell itsef provides rigidity and strength
Have an outer layer
Drink Cartoon
Rubbish Bin
Helmet
Body of a vehicle
Frames
Defination of man-made frames
Constructed by joining separate pieces of material that support and protect various parts
Examples
Brigde
Scaffolding
Skycappers
Cranes
Has no feedback ,cannot respond to the changes in the environment
water tap
Used to change the place of movement
Lever on the bathroom tap
used to contorl : speed/direction/distance/amount of force produced by amovement .
screwjack
pantograph mechanism
hand drill
A clock mechanism
Used to change one type of motion into another
Glue stick
Movement backwards and forwards along a straight line
pile driver
jig saw blade
A needle on a sewing machine
Movement in a straight line
A car moving along a road
sliding door
lift
Movement backwars and fowards in the arc of a cirlce
windscreen wiper
Pendelum of a clock
Movement in crircle
drilling machine
ceiling fan
Pedals on a bike
Class 3
Class 2
In the second class , the load is between the fulcrum and the effort
Arms of a nutcracker , tin opener
Class 1
in the first class , the fulcrum is between the load and the effort
Scissors , boom of an excavator
1) Sturcture come in all shape and size that must resist force, must not collapse during use and must hold parts in place.
2) Constructed by joining separate pieces of material that support and protect various parts
3) The outer shell provides strength and rigidity
4) Span. support, contain and protect
5)
external - the end of the force reaction
interna l- the first force reaction.
6)
Static load - force that has a constant magnitude with force against/withing the structure
dynamic load - force that changes magnitude, position and direction on a structure.
7) Tension, compression, bending, torsion, shearing
Q1. Defination of structures
Q2. What is a frame structure.
1) Sturcture come in all shape and size that must resist force, must not collapse during use and must hold parts in the parts
2) Constructed by joining separate pieces of material that support and protect various parts
3) The outer shell provides strength and rigidity
4) Span. support, contain and protect
5) External and internal. external means the end of the force reaction while internal means the first force reaction.
6) Static load and dynamics load. Static load means force that has a constant magnitude, position and direction on while dynamics load means force that changes magnitude, position and direction on a structure.
7) Tension, compression, bending, torsion and shear
1)-they must resist force
-must not collaspe during use
-must hold parts in the right place
2)constructed by joining seperated pieces of materials,members to support various parts
3)the skins itself provides strenght and rigidity
4)-support
-span
-contain
-protect
5)external-
internal-
6)dynamic-force that changes magnitude,position and directon on a structure
static-force that has a constant magnitude,position and direction on or within a structure
7)-tension
-compreesion
-bending
-torsion
-shear
