Week One: e-‐learning Knowledge Map
Ching (2008): Static loads: structures will gradually respond under a static load, the deformation of the structure will reach a peak when the force is a maximum. Static loads include: -‐ Live loads: an applied load, whose force typically acts in a vertical direction. Examples include: occupancy loads (people, furniture), snow loads, rain loads -‐ Dead loads: the self weight of the structure. Dynamic loads: applied rapidly to the structure, the deformation of the structure is not directly related to the force that is applied. Dynamic loads include: -‐ Wind loads -‐ Earthquake loads
Criteria to think about when considering and selecting materials: -‐ Strength (how strong is the material?) -‐ Stiffness (how flexible is the material?), -‐ Shape, -‐ Material behaviours (materials will behave differently with the force applied), -‐ Economy and sustainability (how expensive? how readily available?). Forces: -‐ tension forces: when a load pulls the structural member apart in opposite directions. ç☐è -‐ compression forces: when a load pushes the structural member. è☐ç Load path diagrams: -‐ considers the applied load, not the self load. -‐ The diagram shows how the load is transferred down into the ground. -‐ Loads are respresented as arrows, these also suggest the direction and scale -‐ The load takes the most simple route through the beams -‐ At the ground there are reaction forces – this is force is equal and opposite so that the structure is stable
There are three types of construction: 1) M ass construction 2) F rame (column and beam) 3) Tensile/fabric Mass construction: 1) Small module (eg. Mud/clay bricks, concrete bricks) -‐ not strong against natural forces 2) Large module (eg. Precast concrete) Small m odule m ass construction: Bricks used in small module mass construction can be: -‐ pressed bricks (vary in colour. Harder the brick, darker the colour) -‐ wire cut/extruded
We started with brick that were placed on top of one another but soon realised that the structure would become unstable when it was built higher.
We chose to create a pattern with the bricks to ensure the structure became more stable and therefore higher.
During this activity we were asked to create the highest structure possible made out of wooden bricks and clay bricks. We chose to use a circular shape, as we believed it would allow us to easily build higher. However, we could not find an easy way to create a roof over the top of the structure due to the way it was constructed. Our choice to include the clay bricks into our construction allowed us to create compression and ensured the structure was more stable.
The self weight and compression force pushing down allows for a stronger structure.
Week Two: e-‐learning Knowledge Map
Ching (2008): Structural system: This system is used to ensure applied loads and gravity support and transmit safely to the ground. Enclosure system: the exterior of the building. Mechanical systems: ensures that services are supplied to the structure.
Structual systems: -‐ Solid – find in early buildings (Egypt, great wall of china), compression is the main force -‐ Surface – example: opera house uses a shell structure -‐ Skeletal – frame system, efficient ways of transforming the load down to the ground -‐ Membrane – used less commonly in the built environment (north court, sails) There can be a hybrid that uses a number of structural systems. Construction systems: make decisions based on these criteria – performance requirements, aesthetic qualities, economic efficiencies, environmental impacts. ESD and selecting materials: -‐ Embodied energy is the total energy used. -‐ Consider what can be reused, design is at the center of the lifecycle of a building and its materials. -‐ Recyclability – reduce, reuse, recycle -‐ Carbon footprint – how much greenhouse gas is produced Local materials, material efficiency, thermal mass, night air purging, solar energy, wind energy, cross ventilation, smart sun design, insulation, water harvesting. Structural joints: -‐ Roller joints -‐ Pin joints -‐ Fixed joints
Three different joints: Roller Joint Pin Joint Fixed Joint -‐ Pin joints and fixed joints are more common -‐ Fixed joints are the strongest as they resist rotation, vertical and horizontal forces. The more joints that are present in a structure the more unstable it will be. Triangles as a shape resist rotation, vertical and h orizontal forces so they are commonly used to create a stable structure.
By bracing the structure and creating two triangles, it will be a lot stronger
Squares can be easily deformed when undergoing forces
During this activity we were asked to construct the tallest tower out of one piece of balsa wood. Our group began disadvantaged as our balsa wood was cut too small so we were required to join three small pieces into one larger piece. Due to our added joints our structure became unstable and was not able to support itself. When forces are applied (even self weight) it causes the structure to deform and is unable to support itself.