Size Optimization

7th March 2016


Size optimization defines ideal component parameters, such as material values, cross-section dimensions and thicknesses. It is used to determine the ideal thickness of a material based on the performance goals and the forces expected to be placed on the component during its life. In an optimization process, it is generally used after freeform optimization once the initial geometry of the component has been defined and interpreted.


As size optimization is concerned with the thickness of a material and dimensions of cross-sections, it is particularly useful when designing composite components which are constructed from a number of layered plys of various thicknesses. With so many options available to the engineer, being able to generate an ideal layout of the composite ply thicknesses can help to reduce development time and guide the manufacturing process.


Like freefrom optimization, the purpose of performing size optimization is to minimise the material being used in a product while reducing its overall weight without compromising on performance goals. The technology can be applied throughout industry to meet weight targets and performance challenges; two examples are presented below.

• Eurocopter Composite Tailboom
The purpose of the project was to improve the performance of a helicopter tailboom. By implementing a series of optimization methods, including size optimization, the buckling load cases and deflection at the end of the tailboom were successfully improved by 10% and 35% respectfully, without increasing weight or fuel efficiency.

• Volkswagen Composite B-Pillar
A recent study at Volkswagen Group Research aimed at defining an efficient design approach for a composite B-pillar with optimized performance and weight. Using free-sizing optimization amongst other methods, the B-pillar was found to be 40% lighter than the metallic original.