Monday, 27 May 2019

Strong Structures with Triangles





Why the triangles are very important for make a structure stable:

Saturday, 16 March 2019

MECHANISM



Mechanisms allows objects to  move. They  transmit and transform force and motion from a motor to a  a receptor. They  make work easier and more comfortable for human  beings.

  • Linear transmission of  motion: 
    • Levers

Class 1 Class 2 Class 3



It has the turning point(fulcrum) between the load and the effort.

It has the load between the fulcrum and the effort It has the effort between the fulcrum and the load
Have a look the next videos about levers: 

what is a lever? 
  


Types of levers:
 
     

      • Pulleys:
        The pulley is a simple machine made with a wheel and a rope or chain. There are three types of pulleys: 
        • Fixed pulley: The pulley is balanced when the force we apply F is equal the load R.
        • Movable pulley: It`s a set of two pulleys, one fixed and another with  linear  movement
        • Compound pulley system: a special combination of fixed and movable pulleys. 
                Examples of pulleys: Elevators, gym equipment, wells, curtains at a theatre, blinds on the windows, the clotheslines, flagpoles to hoist the flag up or to bring it down, cranes, garage doors raise and lower utilising a pulley system, rock climbers use pulleys to help them to climb, timing belt in cars...
    pulley to climb


    Timing belt in cars


           







    Watch this video about pulleys:


        Wednesday, 13 February 2019

        FORCES AND LOADS



        When a force acts on a structure, that force becomes a load to the structure. 
        A typical load that acts on a structure is it's own self-weight or gravitational force. Your own body weight is a load on your skeleton.

        There are basically two types of generic loading on a structure:
        •  Permanent load: it doesn't vary over the time (e.g. own weight).
        •  Variable load: it varies over the time (e.g. weight of snow).
        Stress (internal force) is a force that appears when a structure receives an external force. 
        There are typically 5 different types of stress:

            a) Tension
            b) Compression
            c) Shear
            d) Bending
            e) Torsion

        Friday, 8 February 2019

        TYPES OF STRUCTURES

        A structure is a set of elements arranged in an optimum way to support a body or an object.

        The structure of an object is the ordely distribution of its essential part. This is what gives the object its shape.

        Most large structures are one of the following types: mass, frame, truss, vaulted, shell, geodesic or pneumatic.

        In the next  video  you  can see examples of the different  types  of structures.