Reducing structural mass can be achieved through the use of materials with improved specific mechanical properties or by determining a more efficient form. Structural design optimisation attempts to achieve the latter by determining the most efficient material distribution between the support points and the applied loads. Much of the state of the art focuses on continuum methods which revolve around a Finite Element Mesh that is modified (or the variables associated with it) over multiple iterations until an “optimum” form has been found. For example the Solid Isotropic Material with Penalisation (SIMP) method will vary the material density of each element. However there are difficulties in realising the designs from continuum methods as they require a great deal of subjective interpretation as to where the material boundaries lie.
This project uses a Layout Optimisation (LO) technique that determines the optimum layout of truss elements based on an initial ground structure. The project assesses how well the designs produced using LO translate into physical load bearing components. Test specimens designed using LO are fabricated from titanium Ti-6Al-4V using Electron Beam (EBM) additive manufacturing and are then load tested to failure. The EBM process with Ti-6Al-4V is well suited to this because of its consistent isotropic mechanical properties. Through fabrication and load testing practical considerations can be incorporated into the optimisation process so that the physical test specimens yield at the load(s) specified during the optimisation process.