Numerical and Experimental Investigation on Paperboard Converting Processes
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
An investigation of the mechanical properties of paperboard and its influence on converting processessuch as creasing, folding and forming, from both an experimental and numerical perspective wasperformed. Fundamental research to establish a material model for paperboard, and an experimentalout-of-plane shear test method was suggested. Research where the models were used for verificationwas also done. The numerical model is a combination of continuum and interface models. Thecontinuum model represents the paperboard plies, which is an orthotropic elastic-plastic model withHill criteria and isotropic hardening. The interface model is used for connecting the paperboard pliesand also contributing to the delamination properties during converting processes. The interface modelhas linear elastic behavior followed by the initiation and evolution of damage. Both of these twomodels are available in ABAQUS. An experimental characterization scheme consisting of threeexperiments: in-plane tensile test, double notch shear test and density measurements, was shown to besufficient to predict the creasing and folding behavior.The creasing and folding performance can be well predicted by the model. The impact of ply andinterface properties on different paperboards were investigated by numerical simulations, in order tomimic different production strategies. It was shown that the interface strengths mainly influenced thefolding behavior, whereas different ply properties affected the required creasing force.The forming investigation was conducted in a three dimensions deep pear-shape mould. The numericalinvestigation included the effect of pressure, boundary conditions, material properties, differentdeformation and damage mechanisms, i.e. delamination and plasticity. The results showed thesimulation can capture the failure pattern of experiments and the mechanisms during forming. Toachieve better forming performance with anisotropic commercial paperboard in an axis-symmetricmould, a combination of fixed and free boundary conditions can be used to minimize in-plane straincomponents while enabling delamination. Modification of material properties would enable an evenbetter optimization. Additionally, reduction of anisotropy can improve the forming performance.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. , 29 p.
Trita-HFL. Report / Royal Institute of Technology, Solid Mechanics, ISSN 1654-1472 ; 0538
IdentifiersURN: urn:nbn:se:kth:diva-125883OAI: oai:DiVA.org:kth-125883DiVA: diva2:641055
2013-08-30, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Peerlings, Ron, Professor
Nygårds, Mikael, Professor
QC 201308152013-08-152013-08-152013-08-16Bibliographically approved
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