How can you apply interdisciplinary knowledge to solve aircraft structural analysis problems?

It is no doubt that FEM still holds a powerful tool in analysing complicated aircraft structural problems. However, it is not free from so called 'GIGO' (Garbage In Garbage Out) cases. The pre-requisite knowledge of mathematics, physical principles etc. is essential, in my view, for the development of a certain or special element for a specific problem to be addressed. With the advent of theoretical formulations, it is hardly required. For example, the availability of special elements to handle singularity problems like crack has given away the need of developing a special element or methods by the user. What is the must for the analyst is the perfect understanding of the load path that takes place in structure to get the correct solution.

Computational methods such as finite element analysis (FEA) and computational fluid dynamics (CFD) are used to simulate the behaviour of aircraft structures under various operating conditions (loads). To effectively use these computational methods, one needs to have interdisciplinary knowledge of mathematics, fluid and thermal dynamics (physics) to accurately develop efficient models which will provide accurate solutions.

Optimization techniques play a crucial role in aircraft structural analysis by helping engineers design and analyze aircraft structures to meet performance requirements while minimizing weight, cost, and other constraints. One software that utilizes optimization techniques for structural analysis is nTopology. nTopology is a computational modeling software that provides tools for generative design, advanced simulation, and optimization of complex structures. It enables engineers to create lightweight and efficient designs by leveraging advanced optimization algorithms and simulation capabilities.

It has taken a great stride in developing optimization tools like Optistrut etc. based on different optimization techniques. The application of a particular optimization technique is greatly influenced by the problems at hand. One can use either Shape/Size or Topology optimization or both or any other new promising techniques. A typical machined bracket was identified after ascertaining its feasibility of 3D printing for optimization through sizing as well as topology techniques. The comparison of different attributes between the original and optimised bracket based on sizing and topology revealed that the percentage of weight saving was 24% based on sizing whereas it was 53% based on topology compared to the original machined bracket.

It is important that the analyst collaborates with other stakeholders from design & fatigue domain to ensure that the analysis of the part not only meets the margin policy or other criteria, if any, but also clears it from fatigue point of view. Most of the aircraft structures are subjected to fatigue loading. It has been seen that the parts which clear static analysis are not likely to clear from fatigue point of view. The designer plays an important role in designing the part against fatigue to the extent possible keeping the manufacturability point of view in mind. The knowledge gained by the analyst based on interaction with the other domain stakeholders will definitely reduce the iteration cycles between design, stress & fatigue.

A key for successful development is fluid structure interaction (FSI). Lightweight design is mandatory. Strength and durability can be assured by adopting advanced materials but the high flexibility poses challenges. The multi physics optimization requires an accurate FSI evaluation of KPI for each design variation. Reduced order models coupled with AI are emerging as enablers to enable next generation mobility.

With advancements in computational resources & technology, it is easier to deploy AI/ML approches like SVD, DMD & ROM for time accurate solutions. Furthermore use of AI/ML enables faster turn around for Simulations which were taking days to hours, hours to minutes & minutes to seconds. Earlier these weren't possible/limited to academics but now it's in mainstream industry use.