Composites and material selection process, a systematic approach

Unknown makes unloved, a description all too often still applicable to composite materials when it comes down to material selection. This is why with their third white paper the SLC-Lab and its partners want to pass on some essential tools and methodologies to help designers and OEMs make the right choices. This paper will help you make a well-informed choice that could make a positive effect on your activities. You can download the third white paper now!

While the first two white papers discussed composites and the environment, the third white paper introduces a whole new topic: a systematic approach to the material selection process with the Ashby methodology and the CES Selector tool.

Designing a new or improved product is a highly complex process. In most cases, a multitude of requirements and constraints must be satisfied simultaneously. A bicycle frame, for example must not only be stiff and strong enough to withstand the different mechanical loads acting on it while riding, but at the same time, it must be as light as possible. Limiting material and manufacturing cost will also be a major concern for any bicycle manufacturer.

How can you take into account all these constraints at the same time and find the optimal material for your application? Simply selecting the stiffest or strongest material will likely result in a product that does not satisfy the cost and weight constraints, while the cheapest material will probably not be able to bear the mechanical loads. Very often, the choice is based on the designer’s background and experience, but there are certain risks involved in this approach: a lot depends on the knowledge and background of the designer. The designer may not be aware of all the possible choices, or he may a priori exclude materials that could be valid candidates. It is clear that a great deal of subjectivity can be involved in this selection method.

To avoid subjectivity in the materials selection process, objective and systematic methods for materials selection should be used. One such method, primarily oriented to mechanical designs, was developed by Prof. Michael Ashby of the University of Cambridge. His approach is called the Ashby method. It is described in our third white paper, which you can download now. 


The use of lightweight components stands or falls by the choice of materials. Product value, product costs, production costs, development costs and risks are however difficult to estimate when talking about less well-known materials such as composites. Moreover, the wide range of materials and processes makes selection even more difficult. This is why the Sirris composite experts (SLC-Lab) and the sustainability experts have come up with a series of white papers that go much deeper into the properties and possibilities offered by composites.