The role of the interaction coefficient in the prediction of the fiber orientation in planar injection moldings

Fiber orientation tensors are established descriptors of fiber orientation states in (thermo-)mechanical material models for fiber-reinforced composites. In this paper, the variety of fourth-order orientation tensors is analyzed and specified by parameterizations and admissible parameter ranges. The combination of parameterizations and admissible parameter ranges allows for studies on the mechanical response of different fiber architectures. Linear invariant decomposition with focus on index symmetry leads to a novel compact hierarchical parameterization, which highlights the central role of the isotropic state. Deviation from the isotropic state is given by a triclinic harmonic tensor with simplified structure in the orientation coordinate system, which is spanned by the second-order orientation tensor. Material symmetries reduce the number of independent parameters. The requirement of positive-semi-definiteness defines admissible ranges of independent parameters. Admissible parameter ranges for transversely isotropic and planar cases are given in a compact closed form and the orthotropic variety is visualized and discussed in detail. Sets of discrete unit vectors, leading to selected orientation states, are given.

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In-Plane Liquid Distribution of Nonwoven Fabrics: Part I — Experimental Observations

International Nonwovens Journal ◽

10.1177/1558925002os-01100406 ◽

2002 ◽

Vol os-11 (4) ◽

pp. 1558925002OS-01 ◽

Cited By ~ 2

Author(s):

A. Konopka ◽

B. Pourdeyhimi ◽

H. S. Kim

Keyword(s):

Structural Characteristic ◽

Preliminary Data ◽

Fiber Orientation ◽

Test Method ◽

Liquid Distribution ◽

Moisture Movement ◽

Nonwoven Fabrics ◽

The Impact

In nonwovens, fiber orientation is an important characteristic as it directly influences the properties of the material. Fiber orientation is an important structural characteristic. In modeling the performance of nonwovens, it is desirable to understand the impact of fiber orientation and anisotropy on performance. With respect to absorbency and in-plane wicking, the role of structure anisotropy cannot be underestimated. In a series of papers, we plan to explore the manner in which fluids flow though nonwovens and will develop a framework for the prediction of wicking. This paper reports on the development of an improved test method and presents preliminary data on in-plane moisture movement in a series of nonwoven fabrics.

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Determination of coefficients of friction for laminated veneer lumber on steel under high pressure loads

Friction ◽

10.1007/s40544-020-0377-0 ◽

2020 ◽

Vol 9 (2) ◽

pp. 367-379

Author(s):

Michael Dorn ◽

Karolína Habrová ◽

Radek Koubek ◽

Erik Serrano

Keyword(s):

Surface Roughness ◽

Fiber Orientation ◽

Steel Surface ◽

Practical Applications ◽

Laminated Veneer Lumber ◽

Fiber Angle ◽

Steel Surfaces ◽

Influencing Parameters

AbstractIn this study, static coefficients of friction for laminated veneer lumber on steel surfaces were determined experimentally. The focus was on the frictional behaviors at different pressure levels, which were studied in combination with other influencing parameters: fiber orientation, moisture content, and surface roughness. Coefficients of friction were obtained as 0.10–0.30 for a smooth steel surface and as high as 0.80 for a rough steel surface. Pressure influenced the measured coefficients of friction, and lower normal pressures yielded higher coefficients. The influence of fiber angle was observed to be moderate, although clearly detectable, thereby resulting in a higher coefficient of friction when sliding perpendicular rather than parallel to the grain. Moist specimens contained higher coefficients of friction than oven-dry specimens. The results provide realistic values for practical applications, particularly for use as input parameters of numerical simulations where the role of friction is often wrongfully considered.

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A Hyperelastic Model With Distributed Fibers to Describe Human Supraspinatus Tendon Tensile Mechanics

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-206509 ◽

2009 ◽

Cited By ~ 4

Author(s):

Jennifer A. Kadlowec ◽

Spencer P. Lake ◽

Kristin S. Miller ◽

Louis J. Soslowsky ◽

Dawn M. Elliott

Keyword(s):

Mechanical Behavior ◽

Fiber Orientation ◽

Collagen Fiber ◽

Supraspinatus Tendon ◽

Specific Model ◽

Model Material ◽

Fiber Structure ◽

Nanofibrous Scaffolds ◽

Hyperelastic Model

Tendon tissue is composed of collagen fibers in a hydrated proteoglycan matrix. Although many tendons have fibers that are highly aligned (e.g. flexor tendon), the supraspinatus tendon (SST) of the shoulder has significant distribution of fiber alignment [1]. The alignment and distribution of the fibers likely contributes to the nonlinear and anisotropic mechanical behavior, however this has not been demonstrated. Understanding the role of fiber structure on tendon mechanical behavior, that is, characterizing the structure-function relationships, is critical to evaluate the function of injured, degenerated, or healing tendons and would be invaluable in the design and assessment of tissue engineered tendon replacements. While a structurally based hyperelastic model has been developed for tendon [2], this model contained only a single fiber orientation, which is not adequate for the more distributed fiber structure in the SST. We have recently applied a hyperelastic model formulation that has distributed collagen fiber orientation developed by Gasser and colleagues for the arterial wall [3] to model a tendon analog made from nanofibrous scaffolds [4]. The objective of this study was to build on previous work to apply a hyperelastic fiber-reinforced constitutive model that includes a specific term for fiber distribution to the tensile mechanics of human SST and to evaluate the site-specific model material properties.

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SIKAP KEUANGAN PADA PERUSAHAAN KELUARGA: PERAN MODERASI KOMITMEN KELUARGA

Jurnal Manajemen ◽

10.24912/jm.v20i1.67 ◽

2017 ◽

Vol 20 (1) ◽

pp. 82

Author(s):

Perminas Pangeran

Keyword(s):

Goal Orientation ◽

Family Firms ◽

Interaction Coefficient ◽

Debt Financing ◽

Financial Knowledge ◽

Positive Experience ◽

Family Commitment ◽

Positive Effect ◽

Economic Goal

Penelitian ini bertujuan untuk menguji peran moderasi komitmen keluarga terhadap bisnis pada pengaruh pengetahuan keuangan, pengalaman positif dengan penyedia utang, orientasi tujuan ekonomi terhadap sikap keuangan pada utang. Penelitian dilakukan melalui survey kuesioner terhadap 66 pemilik perusahaan keluarga yang beroperasi di Yogyakarta. Penelitian ini menggunakan analisis regresi moderasi.Hasil penelitian empiris menyimpulkan beberapa hal penting sebagai berikut. Pertama, komitmen keluarga yang tinggi pada bisnis akan memperkuat pengaruh positif dari pengalaman positif manajer/pemilik dengan penyedia utang terhadap sikap keuangan pemilik/manajer pada utang. Kedua, hasil koefisien interaksi Orientasi Tujuan Ekonomi dan Komitmen Keluarga Terhadap Bisnis adalah negatif dan tidak signifikan. Ketiga, hasil koefisien interaksi Pengetahuan Keuangan dan Komitmen Keluarga Terhadap Bisnis adalah positif dan tidak signifikan. Hasil ini berlawanan dengan arah prediksi hipotesis.This study aims to examine the moderating role of family commitment to the influence of the financial knowledge, positive experience with debt suppliers, and economic goal orientation to owner- managers’ attitudes toward debt financing in family firms. This study was conducted through a questionnaire survey of 66 owners of family firms, operated in Special Region of Yogyakarta. This study used moderated regression analysis. The results of this study found several important things as follows. First, the high family commitment toward business strengthened the positive effect of the positive experience with debt suppliers to owner-managers’ attitudes toward debt financing in family firms. Second, the result of the interaction coefficient of economic goal orientation and family Commitment was negative and not significant. Third, the result of the interaction coefficient of financial knowledge and family commitment toward business was positive and not significant. This result was opposite to the direction of prediction of the hypothesis.

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Dynamic stability of non-dilute fiber shear suspensions

Thermal Science ◽

10.2298/tsci1205551w ◽

2012 ◽

Vol 16 (5) ◽

pp. 1551-1555 ◽

Cited By ~ 4

Author(s):

Zhan-Hong Wan ◽

Zhen-Jiang You ◽

Chang-Bin Wang

Keyword(s):

Dynamic Stability ◽

Fiber Orientation ◽

Temporal Stability ◽

Interaction Coefficient ◽

Wave Number ◽

Unstable Wave ◽

Order Structure ◽

General Eigenvalue Problem ◽

Closure Effect ◽

Fiber Interaction

Temporal stability analysis of fiber suspended shear flow is performed. After introducing the second order structure tensor to determine the Folgar-Tucker inter-fiber interactions based on the Langevin?s equation, a system governing the flow stability is derived in conjunction with the fiber orientation closure. Effect of the inter-fiber interactions on the dynamic stability is studied by solving the general eigenvalue problem. Results show that fiber interaction has significant stabilizing effects on the flow. The most unstable wave number changes with the interaction coefficient. For given interaction coefficient, wave number and other relevant parameters, there is a Re number which corresponds to the critical flow. This Re number is related to the wave number.

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