Research progress Arjan Klem

Concept &hypothesis To find a way to create a concrete structural façade, using a bone structure as inspiration, A bone structure is very light, but very strong, because there is only material where it is needed, so the shape is adapted to the forces applied to it. Advantages: Lightweight, strong, use of less material.

Topology optimization; Optimize a shape to the forces applied to it, using the minimum amount of material. A free 2d example program was used to experiment a little with this.

Things I had to do: - Calculate the forces on a standard building - Find a optimization program to calculate the façade of this building The building: 20x20x12 meters Wind load: 1kN/m² Chosen façade thickness: 300mm - This resulted in the input for a program

As the optimization program I use Diana with a optimization script I received from dr. ir. Max Hendriks, who has done some research about optimization in Diana. Now I had to model the input. Optimization in Diana, Max hendriks, May 2007

Some factors are affecting the results: - Mesh Type (triangular/Quadratic) - Mesh division (finer=accurate but slow) - Number of iterations; Every node can be reduced 7 times so the maximum number of iterations is 7*nodes. Sow a finer mesh causes exponentionally more calculating time.

The results of the basic model were satisfying, so I started to develop some variants to explore the possibilities.

Interpretation 1. Making windows in the blue areas using a grid.

2. Random openings using a grid, ignoring the outcome from the earlier calculations

3. Creating smoothed openings, following the blue areas in the original calculation.

Materialization 1. Every element that is used less then 50% will be deleted and every element used more than 50%will be the full thickness of the wall. This results in hard edges; Structure/no structure

2. Same as model 1, but the edges are smoothed.

3. The wall is built in layers, with the most loaded elements (red in Diana) as the thickest part and the least loaded elements as the thinnest. The wall is solid and doesn’t contain windows.

4. Same as model 3, but the thinnest layer is transparent, so the openings in the façade are a result of the structure

General conclusion This way of designing is suitable in situations where the material is put to the limit, like: -High rise (material and weight reduction, while maintaining strength) -Uncommon structures like overhangs This way of designing is very flexible and gives an extra degree of freedom in designing the building.

Recommendations This research also results in some questions that should be investigated: How should these structures be created What solution of materialization has the best mechanical properties What solution of materialization has the best transparency Is it possible to use different materials (one for compression and one for tension for example)