LOGBOOK ENTRY Week 2! Luke Adamson! !
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A cantilever is an object with only one point of support!
! http://en.wikipedia.org/wiki/Cantilever!
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Kiln dried hardwood can be seasoned or dressed. You know its dressed if you can rub it without getting splinters. !
Timber is weakest going along the grain. This is why when timber is laminated together their grain direction is altered in order to give strength.!
When building, a builder is given legal possession of the building site in order to complete the required work.!
If you need a span a long area with a steel beam, it will be hard for the structure to support its own weight. In order to be successful, some steel will have to be removed from the beam to decrease the weight.!
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! http://www.steelconstruction.info/Bridges
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Bracing ‘triangulation’ is an essence of framing.!
http://www.diydoctor.org.uk/projects/forces.htm!
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It is normal to brace in both directions so that the structure is strong enough not to give way in either horizontal directions. Bracing is one of the cheapest whys to achieve rigidity.!
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There are, however, many other ways to create rigidity. Examples of this are using a shear panel, adding in knees or using portal frames of a combination of methods.!
A span is the distance between two different points, whereas the spacing is the distance between like members.!
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CLASSROOM ACTIVITY !
! This weeks classroom activity was about building a bridge and trying to understand the concepts of support and the materials we were using.!
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The idea was to construct a bridge that spanned over the 1.5 metre gap out of the material (balsa wood) that was provided. It was meant to be able to hold as much weight as possible before collasping.!
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For out structure we decided to create a ! structure that was skinny and similar to ! a UB. We crafted the flanges and then ! cut 10mm thick web pieces to place ! inside. Then we place the remaining! material in a similar fashion. !
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Our failure came in two spots. We didn’t! provide enough support at the end of the! structure to hold it down to the ground, ! as well as the fact that it just wasn't strong! enough in the centre due to its weight.!
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This following images are those from another! group whose design was to make vertical strong ! beams and reinforce the joints with extra balsa! wood. !
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Similar to our design, this designs fault was at ! that joins where once enough weight was ! applied the joins gave way. !
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What was learnt from this activity was that there! are many designs that would be able to span the! distance however some would be more efficient ! than others. It is also clear that different material! would act differently in this situation. This was! also an activity where it could be seen how loads are transferred through a structure and the importance of its design.!
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LEARNING LOOP STRUCTURAL SYSTEMS! Solid : early buildings, compression; Great Wall of China! Surface: Sydney Opera House! Skeletal: framing, an efficient way of transferring loads down! Membrane: like sails and sports stadiums. Most structures are hybrids!
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ENCLOSURE SYSTEM! the shell or envelope like the roof or existing walls, windows and doors!
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MECHANICAL SYSTEMS! these provide services to a building and must take into account things like performance, aesthetic qualities, constraints and environmental impacts!
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ESD- ENVIRONMENTALLY SUSTAINABLE DESIGN! Aims to reduce the environmental impact of the construction and use of buildings and designs. This includes reducing embodied energy and materials, create sustainable sites with less impact on the environment.! Commonly used strategies include using local material, thermal mass heating, night air purging, solar energy, wind energy, cross ventilation and smart sun design.!
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THIS WEEKS GLOSSARY TERMS Structural joint- a joint (roller, pin or fixed) that is part of the structure of a design. Frame-a structural system that supports other components of physical construction Column- a structure that helps transfer the load through to ground Bracing- used in construction to provide resistance to forces acting upon it Tension- a state of being stretched, opposite of compression Span- the distance between 2 points
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