STUDIO WEEK 2 Task: Build a stable structure long enough to bridge a 1.5m gap that can support as many blocks as possible.
Materials: -‐Balsa wood -‐Super Glue -‐Blue-‐tack Cutting Knife -‐Pins -‐Tin pencil case for cutting -‐Cutting board
The 1.5m span of the bridge was situated between two tables.
We used tape and pins to create fixed joints allowing 3 strips to be connected so that the bridge would be long enough to span across the 1.5m gaps. We overlapped the strips of balsa by 10cm.
We decided to build a beam structure, considering our material as good in both tension and compression, which are characteristic forces of beams. Our design required the balsa wood to b e cut into 8 equal strips.
We made our cuts following the grain of the balsa wood.
We turned over the strips so that the thinner, stronger sides faced upwards. We then connected the two strips with pins. We found that the pins strengthened the design so we continued to place pins along the length of the b ridge.
As our design had altered due to the convenience of pins, we had 2 extra strips of balsa wood and decided to use one to strengthen the middle of our bridge.
Breaking point of classmate’s bridge.
Many groups bridges had failed at the sides near the table, with minutes to spare, we quickly taped strips of balsa wood to the sides of the bridge where it met with the table. We believed that this would strengthen the design.
Our cross-‐sectional area should have been thicker on the sides near the table, as this was where the structure failed when too great a load was applied.
3 MAIN TYPES OF JOINTS Fixed: Fixed joints offer no flexibility -‐If a load occurs in one member it can cause a bending at the joint E.g. welding Roller: Roller joints comprise of moving parts that only move in one direction E.g. sliding doors Pin: A pin joint should be removable -‐Modes of action can be in two d irections E.g. b olts and truss systems.
Building Systems
ESD (Environmentally sustainable design)
-‐Enclosure (Envelope) System
-‐Structural System -‐Service/Mechanical System Common ESD Strategies: -‐Local materials
BUILDING CONSIDERATIONS
-‐Material Efficiency
-‐Performance requirements
-‐Thermal Mass
-‐Aesthetic quality
-‐Night air purging
-‐Economic efficiencies
-‐Solar energy
-‐Wind energy
-‐ Affordability (initial cost of the building and the life cycle cost)
-‐Cross ventilation
-‐Insulation
-‐Water Harvesting
-‐Smart sun design
-‐Environmental impacts
Mechanical systems e.g. piping, electrical and ventilation systems
Glossary Structural joint Structural joints are connections (or joins) that allow forces to be transferred from one structural element to another. Column A column is a vertical post that is used for support in a building. Tension Tension is a force that pulls a material apart that often causes elongation. Frame A frame is a structure that supports a system. Bracing Bracing is a structural member used to stiffen a framework, often incorporated via a pattern. Span Column pictured in Span is the distance between two structural supports. the Baillieu library. Additional Terminology Recyclability is potential for a product/material to be re-‐used or transformed into a new product. -‐Reduce, reuse and recycle Carbon Footprint is a measure of the amount of greenhouse gases generated during the fabrication, transportation and use of a particular product. Example: Since WOOD has a positive carbon footprint impact (absorbs and stores CO2) it must be replaced (re-‐planted) when sourced in order to have a neutral carbon footprint. Embodied energy is the total energy (oil, water, power) used during all stages of a material’s life (definition from Materials for sustainable sites, by Meg Calkings (2009), page 30).
Life Cycle begins with the extraction of raw materials from the Earth and ends with the disposal of waste products back to the Earth OR recycled (partially or totally) into other products. Stages: Raw Material Acquisition >> Primary Processing and Refining >> Manufacturing >> Delivery >> Construction Use and Maintenance >> Final Disposal Thermal Insulation: moderates heat COOLTH: absorbs cool air Thermal mass: Heat loss/gain (and is a consideration when selecting materials) Water Harvesting: Capturing and saving water for other uses