miun.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Uesaka, Tetsu
Publications (10 of 101) Show all publications
Bergström, P., Hossain, S. & Uesaka, T. (2019). Scaling Behaviour of Strength of 3D-, Semi-flexible-, Cross-linked Fibre Network. International Journal of Solids and Structures, 166(July 2019), 68-74
Open this publication in new window or tab >>Scaling Behaviour of Strength of 3D-, Semi-flexible-, Cross-linked Fibre Network
2019 (English)In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 166, no July 2019, p. 68-74Article in journal (Refereed) Published
Abstract [en]

Anisotropic, semi-flexible, cross-linked, random fibre networks are ubiquitous both in nature and in a wide variety of industrial materials. Modelling mechanical properties of such networks have been done extensively in terms of criticality, mechanical stability, and scaling of network stiffnesses with structural parameters, such as density. However, strength of the network has received much less attention. In this work we have constructed 3D-planar fibre networks where fibres are, more or less, oriented in the in-plane direction, and we have investigated the scaling of network strength with density. Instead of modelling fibres as 1D element (e.g., a beam element with stretching, bending and/or shear stiffnesses), we have treated fibres as a 3D-entity by considering the features like twisting stiffness, transverse stiffness, and finite cross-link (or bond) strength in different deformation modes. We have reconfirmed the previous results of elastic modulus in the literature that, with increasing density, the network modulus indeed undergoes a transition from bending-dominated deformation to stretching-dominated with continuously varying scaling exponent. Network strength, on the other hand, scales with density with a constant exponent, i.e., showing no obvious transition phenomena. Using material parameters for wood fibres, we have found that the predicted results for stiffness and strength agree very well with experimental data of fibre networks of varying densities reported in the literature.

Keywords
Cellulose, Discrete element method, Fibre network, Network strength, Polymer, Uniaxial tension
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34637 (URN)10.1016/j.ijsolstr.2019.02.003 (DOI)
Available from: 2018-10-05 Created: 2018-10-05 Last updated: 2019-04-08Bibliographically approved
Hossain, S., Bergström, P. & Uesaka, T. (2019). Uniaxial Compression of Three-Dimensional Entangled Fibre Networks: Impacts of Contact Interactions. Modelling and Simulation in Materials Science and Engineering, 27(1), Article ID 015006.
Open this publication in new window or tab >>Uniaxial Compression of Three-Dimensional Entangled Fibre Networks: Impacts of Contact Interactions
2019 (English)In: Modelling and Simulation in Materials Science and Engineering, ISSN 0965-0393, E-ISSN 1361-651X, Vol. 27, no 1, article id 015006Article in journal (Other academic) Published
Abstract [en]

This paper concerns uniaxial compression of anisotropic fibre network, as typically seen in the end use of nonwoven and textile fibre assemblies. The constitutive relationship and deformation mechanism have been investigated by using a bead-model to represent the complex structures of the constituent fibres and the fibre networks. The compression stress shows a power-law dependency on the density with a threshold density for both experimental and numerical fibre networks. Unlike the widely studied tri-axial compression of the initially isotropic network, it was found that the contact interaction between the fibres, especially the fibre-fibre contact stiffness (or the transverse compression properties of fibres), has a large impact on all the constitutive parameters. In particular, the exponent values computed based on the softer contact stiffnesses agreed very well with the experimental values reported in the literature. The internal deformation mechanism was similar to the earlier studies that at low compression, the deformation is dominated by the low-energy-mode deformations (i.e. bending and shear), whereas at higher compression, the difference appears: the compression of fibre-fibre contacts, instead of the deformation in the fibre axial direction, takes over.

Keywords
uniaxial compression, deformation mechanics, fibre network, cellulose, polymer, DEM model of fibre network
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34638 (URN)10.1088/1361-651X/aaf1ed (DOI)000453313600001 ()
Available from: 2018-10-05 Created: 2018-10-05 Last updated: 2019-01-17Bibliographically approved
Mattsson, A. & Uesaka, T. (2018). Characterisation of time-dependent, statistical failure of cellulose fibre networks. Cellulose (London), 25(5), 2817-2828
Open this publication in new window or tab >>Characterisation of time-dependent, statistical failure of cellulose fibre networks
2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 5, p. 2817-2828Article in journal (Refereed) Published
Abstract [en]

Cellulosic materials have special advantages for transport packaging, because of their light-weight and recyclable natures and also relatively high specific strength. The strength of such materials is normally evaluated by applying monotonically increasing, quasi-static displacement (or load). However, in real circumstances, the material is subjected to far more complex loading histories, such as creep, fatigue, and random loading. Failures under such circumstances are, not only time-dependent, but also notoriously variable. For example, the coefficient of variation for creep lifetime reaches or even exceeds 100%. The objective of this study is to develop a method to characterise both time-dependent and statistical natures of failures of cellulosic materials. We have used a general formulation of time-dependent, statistical failure, originally proposed by Coleman (J Appl Phys 29(6):968–983, 1958). We have identified three material parameters: (1) characteristic strength, representing short term strength, (2) brittleness parameter (or durability), and (3) Weibull shape parameter related to long-term reliability. These parameters were determined by special protocols of creep and constant loading-rate (CLR) tests for a series of containerboards. Results have shown that these two test methods yield comparable values for the materials parameters. This implies the possibility of replacing extremely time-consuming creep tests with the more time-efficient CLR tests. Comparing the cellulose fibre networks with fibres and composites used for advanced structural applications, we have found that they are very competitive in both reliability and durability aspects with Kevlar and glass-fibre composites.

Keywords
Time-dependent failure, Statistical failure, Fibre network, Strength, Creep, Characterisation, Durability, Reliability
National Category
Materials Engineering Mechanical Engineering
Identifiers
urn:nbn:se:miun:diva-33514 (URN)10.1007/s10570-018-1776-5 (DOI)000431788000004 ()2-s2.0-85045290537 (Scopus ID)
Available from: 2018-04-21 Created: 2018-04-21 Last updated: 2019-03-15Bibliographically approved
Uesaka, T. & Gurnagul, N. (2018). Keynote Speech By Derek Page At The 2010 Progress In Paper Physics Seminar In Montreal, Canada. Journal of Science & Technology for Forest Products and Processes, 6(6), 6-12
Open this publication in new window or tab >>Keynote Speech By Derek Page At The 2010 Progress In Paper Physics Seminar In Montreal, Canada
2018 (English)In: Journal of Science & Technology for Forest Products and Processes, ISSN 1927-6311, E-ISSN 1927-632X, Vol. 6, no 6, p. 6-12Article in journal (Refereed) Published
Abstract [en]

This keynote speech was given at the "Progress in Paper Physics Seminar", which was held in Montreal, Canada in 2010. This was Derek's last speech at an international paper physics conference. The organising committee asked him to send a message to young researchers in the paper physics community. The topic of his talk was "the weakest link in chain" which gives advice that is still timely for researchers that want to make a real difference in the forest products industry. This paper is based on his speaker notes which we were fortunate to find.

National Category
Physical Sciences
Identifiers
urn:nbn:se:miun:diva-34723 (URN)000445553600003 ()
Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-01-18Bibliographically approved
Mattsson, A. & Uesaka, T. (2018). New strength metrics for containerboards: Influences of basic papermaking factors. Nordic Pulp & Paper Research Journal, 33(4), 592-602
Open this publication in new window or tab >>New strength metrics for containerboards: Influences of basic papermaking factors
2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 4, p. 592-602Article in journal (Refereed) Published
Abstract [en]

In end-use, containerboard is subjected to a variety of loading histories, such as seconds of loading/unloading, hours of vibration, days of creep load. The fundamental question is whether the commonly measured static strength represents “strength” under these conditions. Another question is, since those time-dependent failures are notoriously variable, how to describe the probabilistic aspect. This study concerns the characterisation of these different facets of “strength”. In our earlier work, we have investigated the theoretical framework for time-dependent, probabilistic failures, and identified three material parameters: (1) characteristic strength, Sc, representing short-term strength, (2) brittleness/durability parameter, ρ, and (3) reliability parameter, β. We have also developed a new method that allows us to determine all these parameters much faster than typical creep tests. Using the new method, we have started investigating effects of basic papermaking variables on the new material parameters. Among the samples tested, the parameter ρ varied from 20 to 50, and β from 0.5 to 1.0. This suggests that, even within the current papermaking practice, there is a wide operating window to tune these new material parameters. The future work is, therefore, to find specific manufacturing variables that can systematically change these new material parameters.

Keywords
characterisation, characteristic strength, durability, machine positions, paper properties, reliability
National Category
Materials Engineering
Identifiers
urn:nbn:se:miun:diva-34509 (URN)10.1515/npprj-2018-0038 (DOI)000451437900002 ()2-s2.0-85057067396 (Scopus ID)
Available from: 2018-09-26 Created: 2018-09-26 Last updated: 2019-03-15Bibliographically approved
Uesaka, T. (2018). Page'S Theory Of Tensile Strength And The Stress-Strain Properties Of Paper. Journal of Science & Technology for Forest Products and Processes, 6(6), 13-17
Open this publication in new window or tab >>Page'S Theory Of Tensile Strength And The Stress-Strain Properties Of Paper
2018 (English)In: Journal of Science & Technology for Forest Products and Processes, ISSN 1927-6311, E-ISSN 1927-632X, Vol. 6, no 6, p. 13-17Article in journal (Refereed) Published
Abstract [en]

One of the most well-known theories in the area of paper is probably Page's theory of tensile strength. The article was published in Tappi Journal in 1969 [1], and written, in a very articulate way, to explain how tensile strength is determined by fibre properties and inter-fibre bond properties. Because this is the area of great interest to papermakers and pulp manufacturers, the theory has attracted great attention since then. In particular, many paper chemists were fascinated by this intuitive way of describing the relationships between bond and fibre parameters so that the theory became a theoretical foundation for many investigations of dry/wet strength agents. Interestingly, Derek himself was not completely happy with the popularity of the theory. As he noted in his paper, it is a semi-empirical theory, intended to provide a picture of the essential factors affecting tensile strength, but not as an analytical equation to predict some of the model parameters. (We will briefly touch upon Derek's concerns later.) In the late 70s, Derek and his colleague, Raj Seth, another legendary scientist from Pulp and Paper Research Institute of Canada (PAPRICAN, currently, FPlnnovations), launched investigations of the tensile stress-strain curves of paper [2,3,4]. The work depicted complex interplays among network structures, fibre properties and inter-fibre bond properties, again, in a very articulate way. This paper has also influenced a number of studies by younger researchers in the areas of paper mechanics and network mechanics. In this short article, I will try to describe how Derek tackled the problem of understanding the tensile properties of paper in the simplest and most articulate way. Based on this review, I will comment on how far we have gone from his ideas, and try to define some outstanding questions.

National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34726 (URN)000445553600004 ()
Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-01-18Bibliographically approved
Mattsson, A. & Uesaka, T. (2017). Creep failure of fibre network: The Origin of uncertainty. In: : . Paper presented at Svenska mekanikdagar, Uppsala,12-13 juni, 2017. Uppsala
Open this publication in new window or tab >>Creep failure of fibre network: The Origin of uncertainty
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
Place, publisher, year, edition, pages
Uppsala: , 2017
National Category
Engineering and Technology
Identifiers
urn:nbn:se:miun:diva-31858 (URN)
Conference
Svenska mekanikdagar, Uppsala,12-13 juni, 2017
Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2017-11-28Bibliographically approved
Hossain, S., Bergström, P. & Uesaka, T. (2017). Non-Affine Deformation Of Soft Fibre Network. In: : . Paper presented at Svenska Mekanikdagar, Uppsala, Sweden, 12-13 juni 2017 (pp. 46).
Open this publication in new window or tab >>Non-Affine Deformation Of Soft Fibre Network
2017 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-33315 (URN)
Conference
Svenska Mekanikdagar, Uppsala, Sweden, 12-13 juni 2017
Available from: 2018-03-20 Created: 2018-03-20 Last updated: 2019-01-18Bibliographically approved
Hossain, S., Bergström, P. & Uesaka, T. (2017). Nonlinear Compression of Soft Fibre Network. In: Book Of Abstracts Deformation And Damage Mechanisms Of Woodfibre Network- Materials And Structures: . Paper presented at EUROMECH Colloquium 592, KTH Royal Institute of Technology, Stockholm, Sweden, 7 June – 9 June 2017.
Open this publication in new window or tab >>Nonlinear Compression of Soft Fibre Network
2017 (English)In: Book Of Abstracts Deformation And Damage Mechanisms Of Woodfibre Network- Materials And Structures, 2017Conference paper, Oral presentation with published abstract (Refereed)
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-33314 (URN)
Conference
EUROMECH Colloquium 592, KTH Royal Institute of Technology, Stockholm, Sweden, 7 June – 9 June 2017
Available from: 2018-03-20 Created: 2018-03-20 Last updated: 2019-01-18Bibliographically approved
Mattsson, A. & Uesaka, T. (2017). Time-dependent breakdown of fiber networks: Uncertainty of lifetime. Physical review. E, 95(5), Article ID 053005.
Open this publication in new window or tab >>Time-dependent breakdown of fiber networks: Uncertainty of lifetime
2017 (English)In: Physical review. E, ISSN 2470-0045, E-ISSN 2470-0053, Vol. 95, no 5, article id 053005Article in journal (Refereed) Published
Abstract [en]

Materials often fail when subjected to stresses over a prolonged period. The time to failure, also called the lifetime, is known to exhibit large variability of many materials, particularly brittle and quasibrittle materials. For example, a coefficient of variation reaches 100% or even more. Its distribution shape is highly skewed toward zero lifetime, implying a large number of premature failures. This behavior contrasts with that of normal strength, which shows a variation of only 4%-10% and a nearly bell-shaped distribution. The fundamental cause of this large and unique variability of lifetime is not well understood because of the complex interplay between stochastic processes taking place on the molecular level and the hierarchical and disordered structure of the material. We have constructed fiber network models, both regular and random, as a paradigm for general material structures. With such networks, we have performed Monte Carlo simulations of creep failure to establish explicit relationships among fiber characteristics, network structures, system size, and lifetime distribution. We found that fiber characteristics have large, sometimes dominating, influences on the lifetime variability of a network. Among the factors investigated, geometrical disorders of the network were found to be essential to explain the large variability and highly skewed shape of the lifetime distribution. With increasing network size, the distribution asymptotically approaches a double-exponential form. The implication of this result is that, so-called "infant mortality," which is often predicted by the Weibull approximation of the lifetime distribution, may not exist for a large system.

National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-31029 (URN)10.1103/PhysRevE.95.053005 (DOI)000402477200018 ()28618530 (PubMedID)2-s2.0-85020188677 (Scopus ID)
Available from: 2017-06-27 Created: 2017-06-27 Last updated: 2018-09-25Bibliographically approved
Organisations

Search in DiVA

Show all publications