Structures

Structures

1. 1. Structures

   • It is to maintain the object's and not to break when a force acts on then Examples: grooves, elephant's skeleton... Structucture easily identified in the body or object. Ex: bones of vertebrates, frame of a boat or the columns and beams in a building. 1.1. NATURAL AND MAN-MADE STRUCTURES: Natural structures: not made by man. They are in livings brings, in their composition, or the result of a geological process. Ex: shell of a corab, bird's rest or a cave. MAN-MADE STRUCTURES: made by people to satisfy a need. Ex: Legs of a table, case of camera...

2. 2. Forces and loads

   • Physical bodies and objects need a structure to support different forces , like gravity which attracts objects to Earth and cause them ti have weight force: anything that can deform a body (static effect ) or make it move or stop ( dynamis effect )THERE ARE TWO MAIN TYPES OF LOADS: 1. Fixed or permanent loads: they don't vary over time. Ex: it would be the weight of a bridge structure and the elements it has ( columns, roadbed...) 1.2. Variable loads: vary over time. Ex: traffic crossing a bridge or wind hitting a bridge. LOAD: force acting on a structure. It can be fixed or variable. LOADS: produce stresses in the structures of a body. The same load can cause different effects depending on the structures, where they are placed, the direction and the trajectory.