Simulate to innovate

Facebook founder Mark Zuckerberg recently predicted that the next decade could see virtual reality merge with augmented reality to become a staple of everyday life. This could be a sign that there’s a growing hunger for the use of virtual reality and simulation to change our ways of working.

The composites manufacturing industry has also seen the use of virtual technology gather momentum, particularly with the use of virtual prototyping.

Founded more than 40 years ago, the ESI Group has been helping manufacturers from all industries worldwide to bring products to life before they even exist. Virtual prototyping enables ESI’s customers to replace physical prototypes with virtual replicates, saving time and money, improving the whole productivity process and helping firms achieve manufacturing excellence.

Virtual engineering can be used at any stage of a composite component’s development process. It enables evaluation and testing at a much earlier stage and in a range of environments, realistic or imaginary.

Using ESI’s range of industry-orientated applications, the manufacturing processes of composite parts can be realistically simulated to enable fine-tuning. This is coming to life at the National Composites Centre in Bristol with whom ESI has been working closely to use such predictive simulation technology for Liquid Composite Moulding (LCM) processes like Resin Transfer Moulding (RTM). It has proven extremely helpful to visualise resin virtually flowing over a preform before it reaches the manufacturing stage.

“The composites manufacturing process is developed by an iterative process of educated trials,” begins Miroslav Stojkovic, engineering capability manager at the NCC. “What that means is that you make an educated guess with a material’s manufacturing process, then you try to manufacture it, but you may not get it right and have to learn from the mistakes.

“If you are making something of high value, there is the cost implication as well as potential health and safety and other aspects to consider. The benefit of using simulation is that you perform virtual development on a computer rather than on the shopfloor. It defines the manufacturing process.”

The quality of parts manufactured using RTM is greatly affected by the process, defined in terms of the injection scheme and tool temperature cycle, among other variables.

“Since the costs associated with RTM tooling can be large, there is now an increased focus on the role of simulation within this process,” Stojkovic says. “Although a number of RTM simulation tools have been developed, in general manufacturing has been slow to adopt this technology due, in part, to lack of proven methodology and industrial precedents.”

Virtual engineering and simulation is also used in structural analysis and in CAD, especially for complex geometries, to analyse the strength of composites and how they deform before any lay-up is started, again saving both time and money.

“Tooling design is one of the most critical processes in the composite product definition,” states Stojkovic. “Using simulation in RTM, the tooling design and process strategy can be enhanced through the analysis of inlet and vent gate type and location, tool heating strategy and injection pressures.

“Such parameters are defined in order to control the resin flow front and avoid dry spots, optimise the injection time, understand tool heat flux and avoid excessive exothermic temperatures.”

A modelling assignment

Meanwhile, ESI PAM-COMPOSITES has helped predict and resolve problems in press forming, and its PAM-FORM module has been used in examining thermal distortion.

“Automated Fibre Placement (AFP) is an established manufacturing technology and, as such, CAD and AFP robot programming would be typical domains where virtual reality and simulation could be applied,” Stojkovic explains.

Research has been conducted more recently to investigate the influence of heating, compaction and defect formation, such as gaps, laps and wrinkles.

“All of these strands have led to the development of the research modelling tools that should ultimately help achieve better understanding and definition of the process.”

Another problem as to why simulation is used less in composites manufacturing, is skills.

“Each specialist in the development process requires elements of another expert’s skills; the person running the simulation needs to understand the capabilities and limits of the manufacturing process, and the production engineer needs to know the influencing parameters and results of the simulation,” notes Stojkovic. “It’s a different skill set.”

The work of ESI and the NCC has demonstrated that simulation does have a future role to play, but Stojkovic adds: “There’s still work to be done, mainly with trying to convince the industry and communicate that there is significant value in the use of simulation for the development of tools.”

Leslie Fletcher, sales account manager for ESI, explains: “Simulation is becoming reality within the composites manufacturing industry, as its value and benefits are becoming more widely understood.

“Thousands of pounds and staff-hours can be lost through trial and error of developing new manufacturing processes. Adopting simulation at the design and development stages will cut losses by enabling production techniques to be established in a computerised world before we get anywhere near the production line.”

Right first time

ESI’s range of applications offers integrated solutions that allows the analysis and optimisation of each individual manufacturing operation. Applications covered by ESI PAM-COMPOSITES include:

• realistic and predictive simulation of preforming or prepreg thermoforming processes


• Liquid Composites Moulding (LCM) processes


• prediction of manufacturing-induced residual stresses and shape distortion

When Brazilian company, MVC needed to manufacture a 13ft bus side-panel in lightweight composite material to strict quality and robustness requirements, it turned to ESI’s PAM-COMPOSITES solution for simulating RTM processes.

This enabled MVC to minimise the risk of production defects and delays, to get it right on the very first try, and the high-quality part was brought to life in just five weeks.

Meanwhile, as Mark Zuckerberg considers how virtual reality could impact our social lives in the future, ESI and the NCC continue exploring the opportunities simulation brings to the manufacturing industry.

“Virtual reality and simulation will play a crucial role in the future of manufacturing,” Stojkovic concludes. “This role is multi-dimensional and includes virtual process simulation, virtual characterisation, simulation in the performance assessment with the effects of manufacturing, and life cycle analysis.

“All these will increase quality and reduce waste while also lowering the barrier to entry of high value technologies. In an ideal case scenario, this will enable the manufacturing of the future to be truly ‘zero prototype’.”

www.esi-group.com