Structures

A structure is an arrangement of parts joined strongly together. Most objects are arrangements of parts, e.g. atoms, crystals, cells Crystals Atoms / Cells

Structures There are many different types of structures in existence Can you name some structures? Examples of structures include – Buildings, Bridges, Cranes, Chairs. Eiffel Tower Golden Gate

Structures This picture shows Buildings, a tower crane and scaffolding What do you think contributes to strength in structures? Factors that contribute to strength in structures. The strength of the material The shape of the parts The method used to join them together The manner in which they are arranged Tribal Home

Structures There are many very strong structures to be found in nature. How many can you name? Spiders Web Trees

Structures Naturally strong features in useful designs Bee honeycombHoneycomb floor mat Mount Everest Pyramid Egypt

Structures Naturally occurring structures include: A grass leaf A water lily A palm tree leaf Sea arch Car shell Grass Palm tree Water lily Sea arch Shell

Structures Grass leaves have a honeycomb structure which, although very light, are also thick and strong. Grass leaf under a microscope Honeycomb used as a core in sandwiched structures, boards and flooring.

Structures Water lilies have a web-like structure, which grows from the centre to the outside of the Leaf giving it strength. Above the view of the underside of a water lily The Eiffel tower’s giant Lily Pad design of the future. A structure made with parts that extend to meet each other

Structures Palm tree leaves, though light, gain their strength from thin sheets folded into corrugations. Palm tree leaf Corrugated roofing Corrugation used in packaging

Structures Sea Arch. Coastal features, formed by weathering Sea arch Steel arch used to support a roadway Roman Arch

Structures Shells provide shelter, and protect. Thin-shell structures are light weight constructions

Structures Beams come in various shapes and sizes A beam is a strip or section of material used to span a distance Beam

Structures Frames are structures made from sections of materials. The shape which is repeated in the images is the triangle.

Structures A triangle is one of the strongest frame shapes known to man. The implementation of this concept in design is known as triangulation. member joint Adding one more member makes the frame stable.

Structures A strut is the part, which has compressive forces acting upon it. A tie is the part of a structure which has tensile forces acting upon it. Wall Tie Strut

60Kg Structures Calculating Forces The frame opposite supports a Mass of 60Kg. Pin A in the sketch is in equilibrium. Calculate the size of the forces acting on members B and C in the frame. Triangle of Forces diagram. The force at B is calculated as: 600 Cos 60 ° = (600)(0.5) = 300N The force at C is calculated as: 600 Sin 60 ° = (600)(0.866) =519.6N In order to calculate the force of the Mass in Newton’s, the Mass must be Multiplied by 9.81N, rounded to (10).Therefore force equals 600N. 300N 519.6N 60Kg

Structures Factor of Safety is used to provide a margin of lee-way of flexibility over the theoretical capacity of the item in question.