Modelling of the braiding process based on analytical and kinematic approaches[BR]- Integration internship

Abstract

Composite materials are increasingly used in the aerospace, automotive, biomedical and many more industries as substitutes to their conventional metallic counterparts. One particular kind of composite materials are the braided composites that have become the subject of great interest in recent years. Interest in these materials is justified not only by their excellent mechanical properties and behaviour, but also by the cost and time effectiveness of the braiding process.

One aspect of the braiding process that is still generally lacking and needs improvement is the control of the machine, i.e. the correlation between the machine parameters and the geometry of the resulting braid. Experienced machine operators are able to manufacture desired, or acceptable, preforms but excessive trial and errors are usually needed, especially when complex shapes are required. As a result, the manufacturing process can be inefficient. To overcome this limitation, numerical models predicting the braid parameters, on which the mechanical properties of the material are directly dependent, are developed. In this work, two such models are implemented and used to analyse the braid structure for different mandrel shapes in the case of 2D biaxial braiding. Both are kinematic models which, although not as accurate, benefit from short calculation times compared to the more detailed finite element approach. Also, the models contain hypotheses such as the neglect of yarn interaction and yarn slip on the mandrel as well as the assumption of straight yarns in the convergence zone, which could lead to systematic errors.