External functional analysis

 

To define the functions necessary for the product, an External Functional Analysis study was carried out. For each function, an appropriate solution is defined. This process provides justification for the assumptions used to construct the model.

Our search for structure will be done as follows:

1. Topological optimization: General sizing to obtain the arm shape for a kayak in degraded conditions (with 2 people on board), in accordance with the model's limit criteria

2. Variations in arm shape: Vary manufacturing processes, materials. Evaluation Criteria: Compromise of system weight, strength

3. Choice of model based on price and manufacturability criteria

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Study

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A first V1 beam is modelled on the basis of the maximum dimensions imposed on the system. This model is topologically optimized to obtain an optimized shape, allowing us to define 3 other V2 beams, under 3 different manufacturing processes: milling, tube bending and the use of sheet metal.

Then, the V2 beams are tested on the basis of stress criteria: strength and weight. Finally, it is necessary to choose between the remaining models on the basis of objective criteria: price and manufacturability criteria.

 

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Result

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The final solution is a double davit composed of beams made by welding carbon/epoxy composite tubes, and equipped with a cover (not visible in the image). It can support a load of 200 kg, i.e. a kayak with 2 people on board and their equipment.

 

Discussion

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The final structure chosen can still be optimized by looking for standard dimensions in the industry. Similarly, the manufacturing process has a cost that we have not taken into account.

The study of the pivot with the catamaran, with rings, could also be carried out for a study of the storage phase. We focused on the use phase because it is the most critical.