Browsing by Author "Cillie, Johan Hendrik"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- ItemFinite element analysis of a corrugated board panel(Stellenbosch : Stellenbosch University, 2022-11) Cillie, Johan Hendrik; Coetzee, CJ; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.ENGLISH ABSTRACT: Corrugated paperboard packaging plays an integral part in the horticultural industry to protect fresh produce during transportation and distribution. A good package (box) design can mitigate mechanical damage, such as bruising, which leads to food waste and financial loss. Numerical tools, such as finite element analysis (FEA), can help in the design of packaging, but this is made difficult due to the complex behaviour of paperboard. Previously, a model was developed by first testing the constituent paper sheets and applying a homogenisation process (reducing the corrugated geometry to a single layer) to obtain a simplified material model (Starke, 2020). The material model was then used to perform an FEA of an MK-4 box, and could accurately predict the failure load (error 3%), but the in-plane and out-of-plane load-displacement responses were less accurate. This study took a step back and modelled the in-plane compression of a single panel, instead of the complete box, to identify where inaccuracies in the modelled load-displacement response may occur. Since panel compression is not a standardised test, a test jig that enforces simply supported boundary conditions was designed. Material testing was performed on the combined board, including three- and four-point bending, edge crush, flat crush and tensile testing. Panel compression was performed on 200 mm, 300 mm and 400 mm square samples in the cross-direction and machine-direction. Digital image correlation (DIC) was used to measure the out-of-plane deformation. The failure load was found to increase with panel size, but the normalised (based on the sample size) failure load decreased. Detailed and homogenised non-linear finite element models were developed for the bending and tensile tests. The results from these models were compared to measurements and used to calibrate the material properties. The material properties from the four-point bending models were deemed more accurate and were used to create a detailed and homogenised panel compression model. The homogenised model required an initial imperfection (perturbation) for buckling to occur. Both models accurately predicted the failure load and the out-of-plane deformation (errors of < 7% and 18% respectively). However, the in-plane deformation at the point of failure was underpredicted by 64% when compared to the measured crosshead displacement. However, when considering DIC (rather than crosshead) in-plane displacement, the underprediction was only 20%. A box compression test (BCT) with the use of DIC was performed on a 400 mm 400 mm 400 mm regular slotted container. The results of the BCT were compared to the panel compression test. The BCT strength was 36% less than the combined strength of four panels and the out-of-plane displacement for a box was 18% less than for a single panel. The in-plane displacement had the largest difference, 13.1 mm for a box and 3.5 mm for a panel. The larger box displacement could be attributed to the flaps and creases in the box. The results show that the effects of flaps and creases must be included in a finite element model if the box’s load-displacement response is to be accurately modelled.