Optimizing pultrusion of glass-fiber reinforced plastic components

Pultrusion process: (1) creels with reinforcement, (2) resin impregnation bath, (3) folding unit, (4) forming die, (5) control panel, (6) pulling unit, (7) cutoff unit. Source: Skolkovo Institute of Science & Technology and DATADVANCE

Structural components made of glass-fiber reinforced plastic (GFRP) fabricated into complex-profile linear shapes are widely used today in aerospace, civil infrastructure and other industries. Examples include aircraft structural components, elements of power line support structures, and bridge structural elements such as beams, decking and girders. Although somewhat more expensive than comparable components made of traditional materials such as metals, concrete or wood, polymer composite structures can have decisive advantages over their traditional counterparts, especially where weight or corrosion resistance is critical.

However, they still need to be cost-effective. One way to achieve this is by taking advantage of GFRP’s ability to be fabricated into large integral structures with lower production costs than counterparts made of traditional materials. While feasible and already applied in various industries today, this approach requires sound understanding and control of the fabrication process to avoid process-induced shape deformations. When the dimensions of finished items fall outside specified limits, misfits or clashes result when assembling components of complex structures.

The challenges of fabricating GFRP components within specified dimensional tolerances have conventionally been solved experimentally, through trial-and-error variation of process parameters during fabrication. This iterative procedure is expensive, labor-intensive and, above all, not very effective, especially when fabricating large components. Thus, industries that rely on GFRP components have an urgent need for mathematical models that effectively predict process-induced residual stresses and deformations, and reveal how to improve and optimize the fabrication process. Continue reading