The influence of structural variations on the constitutive response and strain variations in thin fibrous materials

Alzweighi, Mossab; Mansour, Rami; Lahti, Jussi; Hirn, Ulrich; Kulachenko, Artem

doi:10.1016/j.actamat.2020.11.003

Cited by 29 publications

(18 citation statements)

References 32 publications

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“…The pressing of the punch can be considered to be quite a controlled process, but friction possibly adds a small variation of the stress levels in the paperboard blank. The non‐uniformities of paperboard result in a variation of constitutive material parameters, and the drying constraints during the manufacturing of paperboard will further contribute to a variation, as numerically proved in Alzweighi et al 39 To include a variation of constitutive parameters requires further testing but, if acquired, is then straightforward to include in the analysis.…”

Section: Resultsmentioning

confidence: 99%

Tray forming operation of paperboard: A case study using implicit finite element analysis

Lindberg

Kulachenko

2021

Packag Technol Sci

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The possibility to perform advanced forming operations of initially plane paperboard paves the way to making products like food trays, plates, cups and other containers as a part of shifting towards a circular bioeconomy. As a part of the ongoing efforts of expanding the product range using paperboard, we performed analyses of the forming operation using simulations. An implicit non‐linear finite element model is built to more accurately than previous studies simulate the tray forming process of paperboard. Two different commercial paperboards are investigated. The use of an implicit solver enabled the inclusion of the creasing pattern into the geometry of the paperboard blank resolving the formation of wrinkles during forming. The material data is extracted from tensile test curves of the investigated paperboards and was fitted accurately using Hill's plasticity with difference in tension and compression accounted for with subsequent failure evaluation. The results showed that the inclusion of the creases in the geometry is vital for getting a correct shape of the formed tray and important for decreasing the risk of failure. The results also showed that friction has a big impact on the formed shape and hence on the stress levels, and therefore supports the means of lowering friction between the blank holder and the blank during the tray forming operation. A stochastic approach is proposed to determine the probability of failure for the boards. The performed failure evaluation is consistent with the field observations. The developed approach enables more precise simulations of paperboard tray forming.

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Section: Resultsmentioning

confidence: 99%

Tray forming operation of paperboard: A case study using implicit finite element analysis

Lindberg

Kulachenko

2021

Packag Technol Sci

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“…Wahlström [ 9 ] investigated the macroscopic effect of FOD on paper stiffness, and the effect of FOD on fibre network model responses has been investigated for different fibrous networks but still needs to be adapted for paper materials. [ 2 ] In a recent study, Alzweighi et al [ 10 ] investigated the effect of network‐scale variations in FOD on the macroscale mechanical response using combined fibre network and macroscopic material modelling.…”

Section: Introductionmentioning

confidence: 99%

“…In addition to differences in boundary conditions, any variation in material properties can be important for a certain mechanical behaviour at a smaller scale and negligible at a larger scale. An example of a study focusing on such research questions is Alzweighi et al, [ 10 ] who investigated the effect of mesoscale (fibre network model) variations in paper materials (density, thickness and FODs) on the macroscale (continuum model) mechanical behaviour. In this study, we include data on different relevant analysis scales to put our results in a context of the multiscale nature of paperboard.…”

Section: Introductionmentioning

confidence: 99%

Microscale deformation mechanisms in paperboard during continuous tensile loading and 4D synchrotron X‐ray tomography

Johansson

Engqvist

Tryding

et al. 2022

Strain

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A better physical understanding of mesoscale and microscale mechanisms behind deformation and failure of paperboard material is important to optimize industrial packaging converting processes and decrease waste. In this study, these mechanisms were investigated using synchrotron X-ray tomography during in situ continuous uniaxial tensile loading. High spatial and temporal data resolution enabled quantification of rapid changes in the material occurring before, during and after material failure. The evolution of 3D strain fields, fibre orientations and sample thickness showed that deformation and failure mechanisms differ significantly between samples tested in machine direction (MD), cross direction (CD) and 45 from the loading direction. In 45 and CD, gradual failure processes could be followed across several load steps.Immediately after failure, the in-plane fracture region was significantly larger in both 45 and CD compared to MD. Both fracture characteristics and strain field distributions differed between the three material directions. Significant fibre reorientation was an active deformation mechanism in 45 already from the beginning of the loading, also present in CD after peak load but absent in MD. The MD-dependent mechanisms interpreted and quantified at the scale of the fibre network in this study can help guide model development and likely have wider applicability to other paper-based materials.

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“…Reliability analysis is widely used in industrial applications, ranging from structural (Chojaczyk et al 2015;Mansour et al 2019a;Hultgren et al 2021a) and mechanical engineering (Papadimitriou et al 2020;Sandberg et al 2017) to materials design (Liu et al 2018;Mansour et al 2019b;Alzweighi et al 2020). Regardless of the application, the reliability is defined as the probability that an intended function is satisfied in the presence of uncertainties.…”

Section: Introductionmentioning

confidence: 99%

Second-order reliability methods: a review and comparative study

Mansour

Olsson

et al. 2021

Struct Multidisc Optim

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Second-order reliability methods are commonly used for the computation of reliability, defined as the probability of satisfying an intended function in the presence of uncertainties. These methods can achieve highly accurate reliability predictions owing to a second-order approximation of the limit-state function around the Most Probable Point of failure. Although numerous formulations have been developed, the lack of full-scale comparative studies has led to a dubiety regarding the selection of a suitable method for a specific reliability analysis problem. In this study, the performance of commonly used second-order reliability methods is assessed based on the problem scale, curvatures at the Most Probable Point of failure, first-order reliability index, and limit-state contour. The assessment is based on three performance metrics: capability, accuracy, and robustness. The capability is a measure of the ability of a method to compute feasible probabilities, i.e., probabilities between 0 and 1. The accuracy and robustness are quantified based on the mean and standard deviation of relative errors with respect to exact reliabilities, respectively. This study not only provides a review of classical and novel second-order reliability methods, but also gives an insight on the selection of an appropriate reliability method for a given engineering application.

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The influence of structural variations on the constitutive response and strain variations in thin fibrous materials

Cited by 29 publications

References 32 publications

Tray forming operation of paperboard: A case study using implicit finite element analysis

Tray forming operation of paperboard: A case study using implicit finite element analysis

Microscale deformation mechanisms in paperboard during continuous tensile loading and 4D synchrotron X‐ray tomography

Second-order reliability methods: a review and comparative study

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