Week 4
CONSTRUCTION WORKSHOP DESIGN BRIEF Using the materials provided, design a structure that will span a 1m gap and be as strong and rigid as possible. Enough to substantially withstand a point load from directly above. MATERIALS Depending on the group divisions, each group is given a different set of materials. Our group is given; • 3 pieces of 30mmx40mmx1200mm structural pine • 1 piece of 3mmx100mmx1200mm plywood sheet • Plasterboard nails • Timber-decking nails
DESIGN Our design is focused on two pieces of structural pine that can span across the whole 1m (the 2 pieces are not modified in any way). These two pines are nailed parallel to each other to the plywood sheet to maintain its position. There is seen to be a gap between the structural pines that are nailed together. The remaining pine are cut into small pieces with the same size and nailed on top of the plywood. Unfortunately during the construction process the design could not be completed. The small pine pieces could not all be nailed on time. Only one piece was used located on the middle point.
THE STUCTURE
WEAK POINT
TESTING Our group is group 4. Our design was able to maintain its structure up to 358kg of force and a deflection from 183 to 240 before breaking. The failure or breaking point of our structure occurred directly on the center point where the force or load was applied. With the present of the crack even before the testing, it can be estimated beforehand that the structure will not be able to withstand as much load as without the crack, not maximum.
Upon making the structure, there is a slight error/ weak point located on the pine piece that is nailed in the center of the structure. A crack is formed, breaking the piece nearly in half. 2 pieces are used to attach the small piece of pine to the plywood. Unfortunately both of the nails cause the crack. In spite of that the piece of pine does not break completely in half, it is still attached with a large crack. The two nails are not in a ‘parallel’ or in a position where they are perfectly lined with one another, thus the piece of pine does not break in half.
The two nails in the center position also create a point of weakness especially with the load applied.
COMPARISSON WITH OTHER GROUPS The structures created by other groups differ from one another. One factor being that the set of materials of each groups are different.
OTHER GROUPS EVALUATION
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DESIGN
Group 1 • Deflection 147-196 • Withstand 315kg load • Testing is positioned vertically • Failure and breaking in the center • The load was distributed very efficiently and evenly with a joistlike system in the center
Group 2 • Deflection 160-245 • Withstand 200kg load • Testing is positioned vertically • Design is similar to group 1 joistlike structure • Use of nails was very efficient and maximum • Minimum number of nails are used to prevent cracking and breaking and the creation of points of weakness around the nail
Group 3 • Deflection 134-200 • Withstand 356kg load • Testing is positioned vertically • Design is similar to group 1 and 2 • Breaking occurs on one side only • The plywood covering one side breaks very easily, however the joist-like system still manages to withstand loads