3So, what is a structure? Something that protects someone or something Something that supports s.o. or s.t.Something that contains s.o. or s.tSomething that…
4Some conceptsA force is a push or pull that tends to cause an object to change its movement or shapeA load is an external force which acts on a structure. (e.g. weight)An stress is an internal force which acts on a structure.
5DEFINITION OF STRUCTURE A structure is an arrangement of elements that resists loads.A structure is an element or a set (group) of elements that withstand (support) loads without breaking or distorting (disforming) excessively (too much).
6What does it mean to withstand a load? Structures withstand loads if they can support all the forces acting on them without collapsing or breaking.Snail Shell,
7TYPES OF LOADSRemember that a load is an external force which acts on a structure.Loads are classified in:Static (or Death) load: is a permanent force, acting on a structure.This includes the weight of the structure itself and the non-moving parts it supports.Dynamic (or Live) load: is a changing, or non-permanent force acting on a structure.This includes the force of the wind and the weight of things that are in, or on a structure.
9TYPES OF STRUCTURES We can classified them attending to their origin. Natural structures: exist in the Nature.Manufactured structures: are built by people.Manufactured
10NATURAL STRUCTURES Are not made by people. Occur naturally in the environment.Examples:SkeletonNestEgg shell
11MANUFACTURED STRUCTURES Are built by people.Are classified in:Mass structuresFrame structuresShell structuresSolid (mass): made almost entirely of matter.Frame: made of separate members (usually thin pieces) put together.Shell: encloses or contains its contents
12MASS STRUCTURES Are made piling up material Examples: Pyramid Dam Wall Castle
16CASTLESCastillo de Bellver (Palma de Mallorca, Jovellanos), Chateau du , Neuschwanstein
17FRAME STRUCTURESAre made from bars joined together to form a 'framework‘Most of the inside part of the structure is empty spaceAre the most common construction choice. Why?because they are relatively easy to design and build, and inexpensive to manufacture,
20SHELL STRUCTURESUse a thin, carefully shaped, outer layer of material, to provide their strength and rigidityThe shape of a shell structure spreads forces throughout the whole structureEvery part of the structure supports only a small part of the load, giving it its strength.PROS (Advantages): Great containers (empty) + Use very little material (thin layer)CONS (Disadv.): A tiny weakness or imperfection on the covering can cause the whole structure to fail.