↓ Braiding Simulation

↓ Draping Simulation

↓ Resin Infusion Simulation

Braiding Simulation

Braiding is a popular manufacturing method for textile preforms, which is most suited to relatively fast manufacture of closed form sections. Possible variations in the braider setup enables different ratios of axial yarns to off axis yarns and, furthermore, depending on relative speeds for the moving bobbins the angles of the off axis yarns can be varied. Further information can be found under Research→Manufacturing Technologies→Flechttechnik.

The IFB is developing new simulation methods for braiding to help optimise machine setups and provide numerical models for mechanical stiffness and failure analysis.

The following shows a general view of a Finite Element braiding simulation. All yarns are fully modelled together the mandrel and braiding ring. At the circumference each yarn has an attached spring element that stretches at a constant force, equal to the bobbin pre-tension. The free ends of the bobbins are either fixed for stationary yarns, or have a clockwise, or anti-clockwise, sinusoidal velocity time history.

Results from the braiding simulation are being used to develop meso-scale models of the final infused composite part. From analysis accurate stiffness can be predicted and work is currently on-going to extend these methods for failure prediction.

Draping Simulation

Draping of textile fabrics is an important first step in the manufacturing process that strongly influences subsequent manufacturing steps, such as resin infusion, and also final part properties for stiffness and failure.
Today, the main draping analysis method used in industry is based on geometric mapping. This method has limitations and consequently the IFB is investigating more accurate macro- and meso-scale Finite Elements methods for accurate draping prediction and coupling to subsequent process and mechanical/failure analysis.

Current research is investigating new constitutive laws for fabrics; for example, for continuous fibre preforms with laser perforated yarns to improve drapeability in the fibre direction.

At the meso scale research is investigating accurate representation of the yarn architecture and stitching suitable for draping simulation. From these results accurate models for meso-scale infusion, stiffness and failure simulation are possible.

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Resin Infusion Simulation

RTM (Resin Transfer Molding), VARI (Vacuum Assisted Resin Infusion) and many other are composite part manufacturing techniques, which (with numerous variations) are used to achieve superb fibre volume fraction, surface finish quality, process repeatability, efficiency etc. These techniques, though being industrially attractive, are still strongly dependent on ones experience and test-error approaches, making them a relatively expensive alternative.
The figure shows an industrial example of a VARI infusion process (Courtesy IAI).

Name	Project (working title)
Justas Sirtautas Anthony Pickett	INFUCOMP (Simulation based solutions for industrial manufacture of large infusion composite parts)

Simulation tools are being developed and improved (eg. PAM-RTM^™). IFB as a research partner closely cooperates with resin and fibre manufacturers as well as software developing companies, aiming to provide simulation based solutions for industrial partners. Topics of interest includes permeability characterisation of the fabrics, infusion process modelling and investigation of various process related phenomena (race-tracking, local fabric compaction, fabric shear influence etc.). The figure on the right hand illustrates the effect of fabric compaction for the resin infusion process (transparent tapered block is pressed onto the fabric layup).

Below, the results of corresponding resin infusion simulations are provided.

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