The main aim of the CUSTOM-FIT project was to create a completely integrated system that would allow the desing, production and supplying of products totally adapted to both, the users’s physical geometry and his/her personal requirements, through the optimization of the ultimate Rapid Manufacturing (RM) Technologies.
That for, into the project frame have been developed new digital data capture systems that allow to insert the customer’s geometryc parameters and also his/her additional preferences, interface’s softwares which interacts with the design programmes to translate the previous data information to its languages, design softwares which allow to define the composition and deposition of structural graded materials and, at the same time, do it in a language understandable by the new created RM Printers that produce graded structure products stablished in the design phase with multimaterial, in a way that the product keeps its applicable mechanic, thermic and bio-compatible charaecteristics.
This processes have been gradually tested (some of them are in the validation process) through its real application in the products developed in the case studies carried out with: customised motorcycle seats, helmets, Jaw & Knee Implants, Prosthetic Socket and Toy Quad Seats for disabled children.
Obviously, the safety is an outstanding matter in all the cases. Moreover, products must accomplish with the legal applicable rules. On the other side, products are exclusive products done in a quantity equal to one. That for, one of the work packages of the project is refering to the conception of a new Virtual Testing Metodology for goods produced with this manufacturing system.
Virtual Test of ‘customized’ products
Virtual Certification is the approval of a design without the aid of a physical test. In the specific case of ‘customized’ products this has been conceited since four different points of view:
• Analytical Approach, in which the functionality of the product is described as mathematical function that subsequently is optimised.
• Bandwidth Approach, in which the product is compared with several standardised products.
• Destining Approach in which the products’ performance is verified and given a go / no go, and
• Iteractive Approach, , in which stepped, automated modifications lead to a product that automatically satisfies the appropriate verification conditions.
BPO, from The Netherlands, is the partner in charge of integrating the virtual certification with the standards and applicable legislation. The company, in its professional development, turns detailed simulations into reliable products. That for, BPO has used their validation on mass produced goods’ historic, achieved on a representative sample following the maxim “one Physical test does not represent all product, Physically testing each copy is no option”.
Andrys Posthuma, the BPO’s leader in the CUSTOM-Fit project believes that “A goal of the project is to improve Europe’s position in the global economy. It is BPO’s believe that this can be achieved when high-end products beat the competition with quality. When the goals of the CF project are met”.
For Virtual Certification is used the Computer Aided Engineering (CAE) which is is the use of information technology for supporting engineers in tasks such as analysis, simulation, design, manufacture, planning, diagnosis and repair. Those allow evaluating the product’s characteristics, properties, feasibility and profitability.
In the research development, the Finite Element Method (FEM) has been mainly used to help in producing stiffness and strength visualizations and displacements in mechanical systems. With the Finite Element Analysis (FEA) complex systems with difficult analytic solutions can be employed. As it is an approximate method FEM precision can be improved by refining the discretization in the facet model, using more elements and nodes (complex points system which becomes net called mesh). Mesh is programmed to contain the structure’s material and properties which define its reaction in front of certain stress forces. Density is assigned to the nodes throughout the material depending on the previous stress determined in a concrete area. Regions which will receive high stress have normally additional node’s density (Mesh density) than that which has a little or nothing. The main points of interest are: material breakable points previously determined borders, corners, complex details and high stressed areas. The mesh behaves as a spider net from which each node spread an element from the mesh to each attached node. This kind of vectorial mesh determines the object material properties, creating several elements.
With this aim, the project partners have developed an interface system with FEA which allows applying this to the specific process required by the product characteristics and the virtual certification of the product. Moreover, all the information has been compiled referring to the legislation which affects the different case studies to finally, investigate the validation methodology and integrate the virtual validation with its applicable regulation and legislative requirements.
Between the different case studies to which this test has been applied can be find the Helmet case. This process consisted in scanning the motorcyclist head. Digital data is complemented with the motorist personal requirements, regarding his/her preferences. After adjusting it to the user’s head, the padding internal structure (which is the customisation issue) virtual certification has been defined with FEA.
With the objective of optimizing the design and padding properties, through FEM based information, this was substantially modified, as the following images reflect:
The project results which are not protected by IPR are disseminated to the general public by a partner in Spain; AIJU, through its Website, press releases and direct e-mail. This information is updated depending on the project results.
Nevertheless, the main tool to transfer the technological knowledge has been conceived through training modules for engineers, managers, scientist and educators, both with physical assistance and on line, which are being developed since some weeks ago for the next months and will allow generating added-value to the manufacturing system in Europe.
This Integrated Project, included into the European sixth frammework programm (http://ec.europa.eu/research/fp6/), is widely participated for the industry representatives, technologically outstanding SMEs, and RTD centers. All of them, coordinated by Delcam in the U.K., closely work together to give a step forward in the development of new RM technologies which benefit both, European society and Industry.
The Project, with a total budget of 16 million euros and rewarded by the European Comisión in about 9 millions, investigates variated subjets as manufacturing, design, scanning, materials, validation, training and consultancy. The integration of all those disciplines offers the potential to change de current manufacturing paradigm and also the market goods’ service and distribution, with new technologies which produces complex products that fits the customer in all the senses, in the proper place and delivery time.
The enterprise BPO is an engineering company. Its main business is the design and optimization of plastic producst with the utilization of Finite Element Analysis (FEA). BPO collaborates with the CUSTOM-FIT project investigati