A structural design process for a next generation aerospace design environment
The current structural sizing process used to design military aircraft was developed when the emphasis was on the design of the most advanced products possible, with the customer bearing the associated risks of its development. However the marketplace has evolved into where the customer expects ‘better, cheaper, faster’ products and at a lower degree of risk. It is not clear if the current structural design processes meet the needs of this type of market. This work argues that the current proprietary process should be replaced by one that is more flexible, allowing the company to adapt its current structural sizing process to meet the needs of a particular product. It includes a study of the current and future engineering environment within a ‘typical’ airframe design organisation. It looked at the current use of structural optimisation technology throughout the design lifecycle and identified barriers to the potential benefits of wider use. Two existing elements of the organisation’s in-house toolset were adapted to size components and the results compared against the literature. This provided an insight into the toolset and the development of proprietary tools. Finally a multilevel ‘global-local’ sizing approach was developed and studied as an alternative to the current, more tightly coupled, somewhat ‘monolithic’, sizing system. Strength, stability and stiffness design criteria were considered. Automation of the process was also considered and compared against the existing sizing process. It was found that the current labour intensive sizing process could be improved upon using some simple techniques. Based on this a future structural sizing process is suggested which could be implemented using in-house or commercially available tools.