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lnnovation in wind power through multi-process-capable systems

News International-French

15 Oct 2020

The BladeFactory research project is searching for new innovations with multi-process-capable systems and automation. The project partners are working on issues from the wind energy industry with the aim of optimising rotor blade production in terms of time, costs and quality. Existing manufacturing processes are to be adapted or newly developed while striving to develop a process structure that enables a parallelisation of the different manufacturing steps.

Gantry system using the CAESA® software program from  SWMS Systemtechnik

Gantry system using the CAESA® software program from SWMS Systemtechnik

Together with 14 project partners, Fraunhofer IWES started the BladeFactory project as coordinator in October 2018. The research project, funded by the BMWi with 7 million euros, is scheduled to last 3.5 years. Manufacturing processes have already been developed to shorten the production time of rotor blades.

These processes are currently being tested and further developed by the associated project partners. The development work takes place at the IWES’ own demonstration centre for industrialized rotor blade production in Bremerhaven. This project was developed within the framework of the predecessor project, BladeMaker.

BladeFactory
The project uses a 30m-long double gantry system. The figure hereupper shows the gantry system using the CAESA® software program from SWMS Systemtechnik. In rotor blade production, the common shell construction method consists in manufacturing two rotor shells and then bonding them together. In the plant, the shells are produced fully automatically with a prefabricated forming tool. Different processes are run through with the help of the two gantries.

The project’s core technology is the development of a multiple-process chain based on proven manufacturing processes. The shells are produced by manually placing glass fibre structures in a forming tool. The manual placement process is very time-consuming and costly and should therefore be automated. The BladeFactory project includes various process technologies that start with the production of the actual mould tool, followed by the direct deposition of fibre materials and the application of adhesive.

A special laying tool was developed by different project partners for each of these processes, which can be attached to both gantries.

The different processes including the corresponding end effectors.

Process chain of the BladeFactory project including the corresponding end effectors.

The use of two gantries has major advantages. No substitution processes are required and the set-up times are considerably reduced. These advantages help achieve the desired parallelization of the production process.

Enabling new manufacturing structures through automation
Rotor blades have been made of composite material for years. The core of this innovation is therefore not the material used but the process technology. The production of rotor blades is still largely manual due to their high complexity and their large dimensions. The BladeFactory project is specifically aimed at automating this manual production.

What is interesting about this research project is the diversity of process technologies. Not only are different raw materials used (glass fibre mats, tapes), but the way in which the material is applied varies. Simple pick & place processes, tape laying strategies and sophisticated draping possibilities are under research. These processes are also interesting for general composite manufacturing outside wind power. It should also be mentioned that another process is being developed for joining the two rotor shells. This process is specifically required for dosing and applying the adhesive that holds the shells together.

As part of this project, SWMS Systemtechnik is conducting special research into the possibilities of integrating CAD/CAM solutions. The CAM chain to be developed includes the Siemens Fibersim, CAESA® Composites and NX CAM/VNCK software programs. The rotor blade’s lifecycle is covered from product development to virtual manufacturing. The three-dimensionality of the depositing process is a major challenge as the fibre material is not deposited in one plane but is directly oriented according to the mould geometry during the laying process (deposited close to the final contour). This requires a six-axis manufacturing process.

The CAM chain to be developed includes the Siemens Fibersim, CAESA® Composites and NX CAM/VNCK software programs.

The Computer-Aided Manufacturing (CAM) chain to be developed includes the Siemens Fibersim, CAESA® Composites and NX CAM/VNCK software programs.

The research project primarily advances the wind power industry and promotes the competitiveness of renewable energy. If manual rotor blade production is automated, the cycle time and labour costs could be reduced while increasing production quality. At the same time, the computer-aided production of composites would also expand, creating advantages outside of the wind power industry.

Multi-process-capable systems with CAM support
In automation technology, a machine is often used to implement a specific production step or process. These production systems are then often arranged in a line to perform their respective process steps according to the production sequence. The steps for manufacturing the forming tool (e.g. by milling), laminate production (ATL/AFP and pick & place processes), the bonding process of the half-shells and grinding are used here as examples for the wind power sector. By means of a novel production environment, the BladeFactory project should make it possible to implement all value-adding processes on one single machine.

However, the ability of a system to carry out different processes using suitable tools and end effectors is a particular challenge for automation technology. This increases complexity but also enables a multitude of process optimizations. To fully exploit these possibilities, it is important to handle the increased difficulty in a controlled and consistent manner. SWMS is developing a continuous process-accompanying CAM environment for multi-process plants. The CAESA® software can already be used to map various laying processes from composite technology. Using the BladeFactory project results, it should now also be possible to handle and carry out several different processes one after the other, in sequence, in the same plant. The processes are not limited to AFP or ATL technologies but can be extended and adapted according to process requirements.

It is now necessary that numerous, varied processes can be consecutively and sequentially integrated independently from the strategy and tools used. Tool changes and general set-up times are also being taken into account. The entire production sequence can be accompanied and mapped using both the real-life and CAM process chains.

Since these are largely specially-developed process technologies, an adaptable software interface has to be developed. For each process, specific manufacturing features are established in which relevant parameters can be specified that have a corresponding effect on the overall process.

Individually-adjustable process parameters are one of the most important features in CAM software because they allow the entire processes to be mapped digitally and optimized accordingly. Over several years of development, CAESA® has established a distinctive process configuration for the ATL and AFP environment.

The pictures show how ATL/AFP processes can be configured in a virtual environment and how this is simulated:

How ATL/AFP processes can be configured in a virtual environment and how this is simulated.

Configuration of a tape laying operation

 

How ATL/AFP processes can be configured in a virtual environment and how this is simulated.

Simulation of an ATL operation via CAESA®
 

For instance, after two shells have cured, any potential defect cannot be reversed. The bonding process can illustrate this problem. When the two shells are bonded together, it is important that the correct amount of adhesive is applied to the right place. Otherwise, residual stresses or insufficient bonding of the individual shell components in the rotor blade may occur, which subsequently render it unusable and result in a rejected component. With automation, the process parameters are specially controlled and precisely dimensioned. This results in fewer defective products. The costs for defect processing are still very high. The user can divide the job into separate sections and configure them as required. This feature helps to optimize time and resources.

The benefit of this is not only the optimization of cycle times but also the reduction of rework times. A further advantage that results from fewer defective products is the conservation of resources. Thus, the improved process quality and reliability contribute to the fact that fewer plastic raw materials are wasted, which significantly reduces the environmental impact.

The process configuration for an adhesive application operation.

Sticking feature from the CAESA® software
The picture shows the process configuration for an adhesive application operation.

Contribution to an improved environmental impact
Obviously, the wind power industry has declined sharply in recent years, although wind power is still one of the most important sources of renewable energy. This is not due to technological failure, but to political and bureaucratic causes. It can take several years from finding a location to the start of construction. Finding a location for a wind farm has become very difficult. The distance to residential areas often triggers discussions due to concerns from the residents. When a suitable location for a wind farm is found, the procedure begins that decides who may build it. Clarifying the financing, finding investors and obtaining permits also takes time. Even if it is financially possible for some countries to switch to wind power or something similar, bureaucracy is a constant impediment.

The project was designed to strengthen the competitiveness of wind power. Since it is one of the most effective renewable energies, the BladeFactory project leads the way to rethinking energy production. Processes are also being researched that could be worthwhile for other industries. The targeted three-dimensional depositing of fibre structures is also of particular interest in the aerospace industry, for example.

In conclusion, this research project presents opportunities for wind power to further develop composite manufacturing technology in general and can also be used to support today’s climate issues.

This article has been edited thanks to Dipl.-Ing. Lars Windels, Founder & Managing Director, M.Eng. Marc Loegel, Team Leader Composites, B.Eng. Falk Wilke, Software Engineer.

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JEC Composites Magazine N°137, featuring Automotive