Characterising the mechanical behaviour of fibre based multi-layered materials by strain field analysis technique
The projects aim was to develop and to improve testing methods to characterise the mechanical behaviour of thin, fibre based multi-layered materials by the application and adaptation of a digital image correlation and strain field analysis technique. The following results were achieved:
- development of new testing devices and setups involving optical strain field analysis to provide improved testing control, to make available local deformation distributions and to investigate material characteristics that are not accessible otherwise; e.g. for paper, board and packaging tensile, compression or indendation tests
- determination of non-standard parameters for paper based materials (e.g. transvers contraction, Poisson’s number, shear moduli, elastic and plastic deformation limits) for the use in constitutive material law descriptions and corresponding finite-element simulations
- characterization procedures for a further elucidation of the complex stress situation during industrial scale converting or forming processes of paper and board or new materials e.g. for lightweight and construction applications
The outcome of the research project is to make available paper based materials as a component or semi-finished product for other branches that can be described, evaluated, designed in a way very similar to other established materials as metal sheets of plastic foils. The advantage is that development rules and design tools from other branches such as lightweight, construction or automotive industry can be used for products from paper technology processes. As a result, sustainable, innovative fibre and paper-based products could open new markets substituting products that are based on crude oil or other fossil raw materials. A well-directed dimensioning e.g. in the field of 3-dimensional packaging will lead to new stable, lightweight products avoiding over-dimensioning. Because of a reduction of grammage this may also result in material and cost savings. Furthermore, a contribution to an improved energy efficiency can be achieved due to a reduction of the specific transport costs.
The research project VF 130044 was funded by the German Federal Ministry of Economic Affairs and Energy BMWi in the programme for the "Promotion of Research, Development and Innovation in disadvantaged areas" based on the decision of the German Parliament and carried out under the umbrella of EuroNorm in Berlin. We would like to express our warm gratitude for this funding and for the support of the involved German companies.