What do Hive do?

We are often asked “What do you do at Hive?”. It’s sometimes difficult to answer due to the broad nature of our work. So, over the coming few months, we aim to show some of our work to provide more clarity. This first article covers the initial design steps of a composite pole; subsequent articles will cover detailed design, manufacture and product testing.

A client in the infrastructure sector wanted to replace wooden and steel poles with lighter weight, low maintenance, electrically insulating composite structures and approached Hive to design, manufacture and test prototypes. Our first step was to understand the pertinent local and national standards and certifications. Often these are based around wood or metal and so the first task is to interpret these standards with respect to composite materials. The design brief was to produce the most efficient structure to withstand wind loads at coastal regions for a pole with a maximum diameter of 90mm. The wind affects the pole, as well as various attached equipment and signs, and deflection must be limited to 150mm for the life of the pole (50 years). Iterative designs showed a range of potential products in terms of wall thickness, mass and manufactured cost for different resin and reinforcement combinations. Fibre volume fraction was varied in order to provide options for different production processes (pultrusion or filament winding) and reinforcement styles. These iterative designs were analysed with pole tip deflection as the primary constraint where the thin-walled, high volume-fraction iteration as circled below is the most efficient.

However, analysing on a cost basis, the overall optimal product does not necessarily coincide with the technically ideal design. This is down to differences in density and cost per kg of the resins, fibres, reinforcement types, and additives, along with speed sensitivity of the manufacturing process to fibre packing. For this design, the better solution lies somewhere in the green hatched zone below.

Ultimately, the best option will depend on factors that require a more detailed mechanical, composite and production design evaluation to further optimise the product. This will be covered in more detail as part of our next article.