Leonardo AW09

The Leonardo AW09 helicopter is Leonardo’s new single-engine rotorcraft, designed for transport, emergency services and aerial work. To enter service it must pass a certification programme, so engineers must prove every structural component with traceable calculations.

For the AW09 helicopter certification program, SIM4FLIGHT handled the realization of detailed Finite Element (FE) models. Our activities focused on Stress Recovery under Limit Load conditions and the definition of the Transfer Function for fatigue calculations

Our work on the Leonardo AW09 helicopter

First, we built detailed FE models of the areas indicated by the client, with a fine mesh around holes, fillets and attachments. Then we extracted stresses at Limit Load and compared them with the material allowables, so as to calculate the margins of safety.

In addition, we defined the Transfer Function, that is the relationship between external loads and the stress at critical points. As a result, the fatigue calculation can be repeated over many flight conditions without rerunning the full model each time.

Why it matters in certification

In a certification programme every number must be traceable to its source. For this reason, our reports set out assumptions, load cases, models and results, so that the client’s design office can follow the reasoning and present it to the authority. On the Leonardo AW09 helicopter, too, we worked with the client’s tools and formats: HyperMesh, OptiStruct and HyperView.

What the client keeps

In the end the client has documented, reusable models as well as the stress reports. In fact, if the design changes, the FE model can follow without starting from scratch. The work on the Leonardo AW09 helicopter falls within our structural verification and FEM simulation services. If you have a programme in certification, write to us from the contact page.