Nonlinear Properties of High Strength Paperboards

1999 ◽  
Vol 121 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Y. P. Qiu ◽  
M. Millan ◽  
C. H. Lin ◽  
T. D. Gerhardt
Keyword(s):  
Material Properties ◽  
Solid Mechanics ◽  
High Strength ◽  
Nonlinear Material ◽  
Limited Data ◽  
Plane Shear ◽  
Nonlinear Properties ◽  
Out Of Plane ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

Paper is a highly anisotropic and nonlinear material. Solid mechanics research on paper structures has been hampered by limited data on the nonlinear material properties of paperboards. In particular, it has been difficult to measure shear and z-directional properties. In this paper, nonlinear material response of paper laminates under simple loading conditions (uniaxial compression in three directions and in plane shear) are presented. Also, data is presented for various Poisson’s ratios. It was found that paper behaves differently along the thickness direction than along the in-plane directions. Poisson’s ratios are usually nonlinear with large deformation. In-plane Poisson’s ratios decrease, while out-of-plane Poisson’s ratios increase with the applied load.

Out-of-plane Poisson’s ratios of paper and paperboard

2002 ◽  
Vol 17 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Niclas Stenberg ◽  
Christer Fellers
Keyword(s):  
Out Of Plane ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

A Finite Element Based Procedure for Simulating the Transient Response and Failure of a Two-Dimensional Continuum With Nonlinear Material Characteristics

1973 ◽  
Vol 95 (1) ◽  
pp. 345-352 ◽  
Author(s):  
D. B. Wallace ◽  
A. Seireg
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Impulsive Loading ◽  
Nonlinear Material ◽  
Two Dimensional ◽  
Arbitrary Geometry ◽  
Failure Patterns ◽  
Nonlinear Properties ◽  
Hollow Cylinders ◽  
Failure Theories

This paper presents a finite element based procedure for the analysis and graphic display of the response and failure patterns of a two-dimensional continuum subjected to impulsive loading. Elastic, anelastic, plastic and other nonlinear material properties and failure theories can be incorporated in the analysis. The procedure is illustrated by examples of elastic and anelastic impact of solid and hollow cylinders. The developed technique gives a powerful tool for the evaluation of transient stresses, deformations, yield and fracture modes in two-dimensional continuum with arbitrary geometry and nonlinear properties.

scholarly journals Novel Methodology for Experimental Characterization of Micro-Sandwich Materials

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4396
Author(s):  
Samuel Hammarberg ◽  
Jörgen Kajberg ◽  
Simon Larsson ◽  
Ramin Moshfegh ◽  
Pär Jonsén
Keyword(s):  
Automotive Industry ◽  
Numerical Models ◽  
Constitutive Models ◽  
High Strength ◽  
Image Correlation ◽  
Displacement Fields ◽  
Plane Shear ◽  
Cold Forming ◽  
Out Of Plane ◽  
Sandwich Materials

Lightweight components are in demand from the automotive industry, due to legislation regulating greenhouse gas emissions, e.g., CO2. Traditionally, lightweighting has been done by replacing mild steels with ultra-high strength steel. The development of micro-sandwich materials has received increasing attention due to their formability and potential for replacing steel sheets in automotive bodies. A fundamental requirement for micro-sandwich materials to gain significant market share within the automotive industry is the possibility to simulate manufacturing of components, e.g., cold forming. Thus, reliable methods for characterizing the mechanical properties of the micro-sandwich materials, and in particular their cores, are necessary. In the present work, a novel method for obtaining the out-of-plane properties of micro-sandwich cores is presented. In particular, the out-of-plane properties, i.e., transverse tension/compression and out-of-plane shear are characterized. Test tools are designed and developed for subjecting micro-sandwich specimens to the desired loading conditions and digital image correlation is used to qualitatively analyze displacement fields and fracture of the core. A variation of the response from the material tests is observed, analyzed using statistical methods, i.e., the Weibull distribution. It is found that the suggested method produces reliable and repeatable results, providing a better understanding of micro-sandwich materials. The results produced in the present work may be used as input data for constitutive models, but also for validation of numerical models.

Three-Dimensional Constraint Effects on the Slitting Method for Measuring Residual Stress

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
C. Can Aydıner ◽  
Michael B. Prime
Keyword(s):  
Residual Stress ◽  
Plane Strain ◽  
Plane Stress ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Out Of Plane ◽  
Sample Width ◽  
Poisson's Ratios ◽  
Poisson’S Ratios ◽  
Calibration Coefficients

The incremental slitting or crack compliance method determines a residual stress profile from strain measurements taken as a slit is incrementally extended into the material. To date, the inverse calculation of residual stress from strain data conveniently adopts a two-dimensional, plane strain approximation for the calibration coefficients. This study provides the first characterization of the errors caused by the 2D approximation, which is a concern since inverse analyses tend to magnify such errors. Three-dimensional finite element calculations are used to study the effect of the out-of-plane dimension through a large scale parametric study over the sample width, Poisson's ratio, and strain gauge width. Energy and strain response to point loads at every slit depth is calculated giving pointwise measures of the out-of-plane constraint level (the scale between plane strain and plane stress). It is shown that the pointwise level of constraint varies with slit depth, a factor that makes the effective constraint a function of the residual stress to be measured. Using a series expansion inverse solution, the 3D simulated data of a representative set of residual stress profiles are reduced with 2D calibration coefficients to yield the error in stress. The sample width below which it is better to use plane stress compliances than plane strain is shown to be about 0.7 times the sample thickness; however, even using the better approximation, the rms stress errors sometimes still exceed 3% with peak errors exceeding 6% for Poisson's ratio 0.3, and errors increase sharply for larger Poisson's ratios. The error is significant, yet, error magnification from the inverse analysis in this case is mild compared to, e.g., plasticity based errors. Finally, a scalar correction (effective constraint) over the plane-strain coefficients is derived to minimize the root-mean-square (rms) stress error. Using the posed scalar correction, the error can be further cut in half for all widths and Poisson's ratios.

scholarly journals Tightness and Material Aspects of Bolted Flange Connections With Gaskets of Nonlinear Properties Exposed to Variable Loads

2016 ◽  
Vol 61 (3) ◽  
pp. 1409-1416
Author(s):  
R. Walczak ◽  
J. Pawlicki ◽  
A. Zagórski
Keyword(s):  
Finite Element Analysis ◽  
Material Properties ◽  
Complex Loading ◽  
Nonlinear Material ◽  
Energy Industry ◽  
Element Analysis ◽  
Nonlinear Properties ◽  
Precise Calculation ◽  
Design Calculations ◽  
Bolted Flange

Abstract The paper presents the problems regarding bolted flange connections with gaskets used in chemical, petrochemical and energy industry. The aim of the research is to present state of knowledge regarding pipelines and apparatus in industrial installations and rules and regulations regarding flange connections tightness. Additionally a calculation example regarding flange connection according to ASME VIII DIV 1 requirement and then detailed Finite Element Analysis presented; impact of nonlinear material properties (gasket loading unloading curves) on the connection tightness for complex loading programme is shown. It is finally concluded that in addition to usual design calculations more precise calculation is needed to fully verify behaviour of sealed connection at complex extreme variable loadings. Material aspect is very important at designing, testing, service and maintenance; taking it into consideration may avoid many problems related to safe exploitation.

A Comparison of Nonlinear Bending and Vibration of Hybrid Metal/CNTRC Laminated Beams with Positive and Negative Poisson’s Ratios

2020 ◽  
pp. 2043007
Author(s):  
Yin Yu ◽  
Hui-Shen Shen
Keyword(s):  
Nonlinear Vibration ◽  
Material Properties ◽  
Perturbation Approach ◽  
Beam Model ◽  
Laminated Beams ◽  
Nonlinear Bending ◽  
Laminated Beam ◽  
Motion Equations ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

Carbon nanotube reinforced composite (CNTRC) is one of the novel classes of advanced composite materials. This paper investigates the nonlinear bending and nonlinear vibration responses of hybrid laminated beams made of CNTRC layers bonded with metal layers on the top and bottom surfaces. We proposed a hybrid metal/CNTRC laminated beam for which out-of-plane Poisson’s ratio is negative. The effective material properties of CNTRC layers are graded in a piece-wise pattern across the thickness of the beam. The material properties of both CNTRC layer and metal layer are temperature dependent. The beams are rested on an elastic foundation and are located in thermal environments. Reddy’s higher-order beam model is used to establish the motion equations of the hybrid metal/CNTRC laminated beam. The motion equations include the von Kármán geometric nonlinearity, the thermal effects and the beam-foundation interaction. By employing a two-step perturbation approach, the bending and nonlinear vibration solutions are obtained. A comparison of nonlinear responses of hybrid metal/CNTRCl laminated beams with positive and negative Poisson’s ratios (NPRs) under different thermal environmental conditions is carried out and discussed in detail.

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