Efficient raw material usage & increased buckling strength

A new tolerance and measurement concept for tie rods at RO-RA

We always strive for connecting elements in the safest and most efficient way. With our tie rods, as one of our main business fields, we want to achieve that and contribute to a more sustainable flying with our lightweight design.

The centrepiece of our tie rods is the tube, which is also a key element in terms of stability. Therefore, an instability analysis including all possible deviations from a theoretically perfectly straight tube is important for the functionality and safety. Deviations can come from manufacturing processes such as forming, heat treatment and machining.

We are always working on further improvements of our products and processes to create more value for our customers and hence we implemented an improved tolerance and measurement concept for our tubes based on Airbus standards. Therefore, we could on the one hand increase the robustness of our tube manufacturing process. On the other hand we could increase the stability properties of our tie rods. This results in a more efficient use of raw materials by reducing rejection rates in the manufacturing process.

The development and validation of these concepts was done by our great employees at RO-RA. We used fully parametrized finite element (FE) simulation models representing all deviations that can occur in reality. We also implemented fully automatized analysis workflows for efficient and reliable data driven analyses (an example of the FE model and data analysis is shown in the figure below). For the analysis of simulation and test data we made use of machine learning tools to identify and quantify the most relevant and sensitive parameters regarding the stability properties of our tie rods. Based on that we could then further take into account the influence of various adapter end geometries in our tolerance and measurement concepts resulting in the improvement of one of our main products rods.