Determination of Mechanical Property Gradients in Heat-Affected Zones of Ferritic Steel Weldments by Shear-Punch Tests

Nanoindentation is a widely accepted test method for materials characterization. On account of the complexity of contact deformation behavior, design of parametric constitutive models and determination of the unknown parameters is challenging. To address the need for identification of mechanical properties of viscoelastic/plastic materials from nanoindentation data, a combined numerical finite element/optimization-based indentation modeling tool was developed, fully self-contained, and capable of running on a PC as a stand-alone executable program. The approach uses inverse engineering and formulates the material characterization task as an optimization problem. The model development consists of finite element formulation, viscoelastic/plastic material models, heuristic estimation to obtain initial solution boundaries, and a gradient-based optimization algorithm for fast convergence to extract mechanical properties from the test data. A four-parameter viscoelastic/plastic model is presented, then a simplified three-parameter model with more rapid convergence. The end result is a versatile tool for indentation simulation and mechanical property analysis.

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Air-coupled non-contact mechanical property determination of drug tablets

International Journal of Pharmaceutics ◽

10.1016/j.ijpharm.2008.03.020 ◽

2008 ◽

Vol 359 (1-2) ◽

pp. 25-34 ◽

Cited By ~ 18

Author(s):

Ilgaz Akseli ◽

Cetin Cetinkaya

Keyword(s):

Mechanical Property ◽

Contact Mechanical

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Microstructure and mechanical property of in-situ nano-particle strengthened ferritic steel by novel internal oxidation

Materials Science and Engineering A ◽

10.1016/j.msea.2014.05.020 ◽

2014 ◽

Vol 609 ◽

pp. 293-299 ◽

Cited By ~ 18

Author(s):

Hao Tang ◽

Xiaohua Chen ◽

Mingwen Chen ◽

Longfei Zuo ◽

Bin Hou ◽

...

Keyword(s):

Mechanical Property ◽

Internal Oxidation ◽

Ferritic Steel ◽

Nano Particle ◽

Microstructure And Mechanical Property

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Stiffness and strength properties of five paperboards and their moisture dependency

TAPPI Journal ◽

10.32964/tj19.2.71 ◽

2020 ◽

Vol 19 (2) ◽

pp. 71-85

Author(s):

GUSTAV MARIN ◽

MIKAEL NYGARDS ◽

SOREN OSTLUND

Keyword(s):

Mechanical Properties ◽

Mechanical Property ◽

Shear Strength ◽

Three Dimensional ◽

Strength Properties ◽

Bending Stiffness ◽

Moisture Ratio ◽

Machine Direction ◽

Product Series

Five commercial multiply folding boxboards made on the same paperboard machine have been analyzed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. The paperboards are normally used to make packages, and because the bending stiffness and grammage varies, the performance of the packages will differ. Finite element simulations can be used to predict these differences, but for this to occur, the stiffness and strength properties need to be deter-mined. For efficient determination of the three-dimensional properties in the machine direction (MD), cross direction (CD), and Z direction (ZD), it is proposed that the paperboard should be characterized using in-plane tension, ZD-tension, shear strength profiles, and two-point bending. The proposed setups have been used to determine stiff-ness and strength properties at different relative humidity (20,% 50%, 70%, and 90% RH), and the mechanical proper-ties have been evaluated as a function of moisture ratio. There was a linear relation between mechanical properties and moisture ratio for each paperboard. When the data was normalized with respect to the standard climate (50% RH) and plotted as a function of moisture ratio, it was shown that the normalized mechanical properties for all paperboards coincided along one single line and could therefore be expressed as a linear function of moisture ratio and two constants. Consequently, it is possible to obtain the mechanical properties of a paperboard by knowing the structural prop-erties for the preferred level of RH and the mechanical property for the standard climate (50% RH and 23°C).

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