A simple method to evaluate anisotropic plastic properties based on dimensionless function of single spherical indentation – Application to SiC whisker-reinforced aluminum alloy

This study proposes a method of reverse analysis to estimate the anisotropic plastic properties of engineering steels by spherical indentation. The method takes into consideration materials that obey the work-hardening law and show in-plane anisotropic yield stress. Finite element analysis was first carried out to compute the indentation behavior of such materials, showing that a permanent impression exhibited an anisotropic shape which was strongly dependent on the orthotropic axis. Based on the anisotropy of the impression geometry, we developed a simple approach to determine the yield stress, work-hardening exponent and yield stress ratio. The approach consists of several functions related to the parameters of two impression geometries, produced by dual spherical indentations with different indentation forces. Since the present method uses only two impression geometries and does not necessitate indentation force — displacement curves (indentation curves), it is a particularly useful technique to evaluate "indistinguishable materials" which are special sets of materials with distinct plastic properties, yet yield almost identical indentation curves.

Download Full-text

A Simple Method for Measuring Plastic Properties of Power Hardening Metals via the Indentation Curve with a Large Depth

Advances in Materials Science and Engineering ◽

10.1155/2020/7372807 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Ying Kan ◽

Yiwen Wu ◽

Liping Ren ◽

Huaining Chen

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Indentation Depth ◽

Spherical Indentation ◽

Strain Hardening Exponent ◽

Finite Element Analyses ◽

Simple Method ◽

Plastic Properties ◽

Indentation Curve ◽

Depth Curves

The spherical indentation technique provides an easy way to evaluate the integrity of in-service structures because it is nondestructive. In this study, a simple method was proposed to measure mechanical properties such as the yield strength, the ultimate tensile strength, and the strain hardening exponent from the indentation curve at a large indentation depth, which is 0.4 times of the indenter radius. Based on finite element analyses, a simple function was proposed to relate representative stress to indentation data. Besides, representative strains at different indentation depths were identified according to the load-depth curves from simulations. The calculated plastic properties from the developed method were compared well with experimental results.

Download Full-text

The influence of pavement degradation caused by cyclic loading on its failure mechanisms

The Baltic Journal of Road and Bridge Engineering ◽

10.3846/bjrbe.2016.21 ◽

2016 ◽

Vol 11 (3) ◽

pp. 179-187 ◽

Cited By ~ 1

Author(s):

Marcin Gajewski ◽

Stanisław Jemioło

Keyword(s):

Yield Condition ◽

Limit Load ◽

Flow Rule ◽

Smooth Approximation ◽

Simple Method ◽

Plastic Properties ◽

The Road ◽

Plastic Materials ◽

Number Of Cycles ◽

Elastic Plastic Materials

In this paper, a simple method is proposed to estimate capacity of multilayered road structure including the degradation of the elastic and plastic properties of the constituent materials. In the study boundary value problem modeling interaction of wheels with road surface layer in the frame of large deformation theory for elastic-plastic materials was formulated. Plastic properties of the material were described by the flow rule un-associated with yield condition. The Coulomb-Mohr yield condition was assumed and the potential for plasticity is its smooth approximation. In addition, in constitutive modeling the dependence of the Young’s modulus and cohesion of the material from the number of cycles is taken into account. This paper presents qualitative findings in relation to mechanical behavior of the road structure, i.e., for example, the development of plastic zones with increasing load for un-degraded and degraded materials. In addition, a parametric study of the influence of the degradation ratio of the elasticity and plasticity properties for road structure failure mechanism (limit load value) was made.

Download Full-text

Effect of silicon carbide particles on the mechanical and plastic properties of the AlMg6/10% SiC metal matrix composite

Journal of Composite Materials ◽

10.1177/0021998318765622 ◽

2018 ◽

Vol 52 (24) ◽

pp. 3351-3363 ◽

Cited By ~ 5

Author(s):

Alexander S Smirnov ◽

Vladimir P Shveikin ◽

Evgeniya O Smirnova ◽

George A Belozerov ◽

Anatoly V Konovalov ◽

...

Keyword(s):

Silicon Carbide ◽

Aluminum Alloy ◽

Metal Matrix Composite ◽

Matrix Composite ◽

Metal Matrix ◽

Tensile Tests ◽

Mechanical Tests ◽

Plastic Properties ◽

Initial Yield Stress ◽

Reinforcing Particles

This work deals with studying the effect of reinforcing SiC particles on the mechanical and plastic properties of a metal matrix composite with a matrix of aluminum alloy AlMg6 (the 1560 aluminum alloy according to the Russian State Standard GOST 4784−97). We assess this effect using the results of mechanical tests at the microscale and macroscale levels. The paper analyzes the fracture mechanism at the microlevel under tensile and compressive stress conditions, as well as the type of contact between the composite constituents. The experimental results obtained for the metal matrix composite are compared with analogous experimental data for the AlMg6 alloy and a compacted material made from the AlMg6 alloy (a compacted powder without addition of SiC reinforcing particles). The studied compacted materials were not previously subjected to extrusion. The tests show a decisive influence of the reinforcing particles on the plastic and mechanical properties of the AlMg6/10% SiC metal matrix composite under compression and tension. For example, the addition of silicon carbide increased the initial yield stress of the compacted material by 26% under tensile tests, and the percentage elongation after fracture was increased up to 1.1%, while it amounted to 0.02% for the compacted material without addition of silicon carbide. Under compression, on the contrary, the addition of silicon carbide degraded plastic properties. As a result, the percentage compression before cracking was 28.4% and 57.9% for the compacted materials with and without addition of silicon carbide, respectively.

Download Full-text

Plastic properties determination using virtual dynamic spherical indentation test and machine learning algorithms

Journal of Mechanical Science and Technology ◽

10.1007/s12206-021-1230-8 ◽

2022 ◽

Author(s):

Mohammad Kashfi ◽

Sepehr Goodarzi ◽

Mostafa Rastgou

Keyword(s):

Machine Learning ◽

Learning Algorithms ◽

Indentation Test ◽

Machine Learning Algorithms ◽

Spherical Indentation ◽

Plastic Properties

Download Full-text

Effect of Granule Size in Semi-Solid Slurry on Rheo-Extrusion of A7075 Aluminum Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.561-565.291 ◽

2007 ◽

Vol 561-565 ◽

pp. 291-294 ◽

Cited By ~ 6

Author(s):

Yasuhiro Uetani ◽

Ryotaro Nagata ◽

Hidetoshi Takagi ◽

Kenji Matsuda ◽

Susumu Ikeno

Keyword(s):

Aluminum Alloy ◽

Solution Treatment ◽

Hot Extrusion ◽

Granule Size ◽

Extrusion Ratio ◽

Peak Hardness ◽

Simple Method ◽

Ram Speed ◽

Semi Solid ◽

Solid Granule

Rheo-extrusions of A7075 aluminum alloy were carried out utilizing semi-solid slurries with different solid granule sizes, which were made by a simple method combined a thin upright tube with a water-cooled tube. Every structure of slurries was granular and average solid granule sizes could be controlled by 0.05 to 0.11mm. These slurries were extruded to round bars at extrusion ratio of 36 and press ram speed of 10mm/s mainly, just after cooling to 833K ( fs > 0.9 ). All of the slurries could easily be extruded to bars with smooth surfaces at much low extrusion forces than those of hot-extrusions. Tensile strength of rheo-extruded bars after solution treatment increased with decreasing of the solid granule size. Peak hardness level at T6 condition equivalent to that of hot-extrusion could be obtained at the finest solid granule size.

Download Full-text

Numerical verification for instrumented spherical indentation techniques in determining the plastic properties of materials

Journal of Materials Research ◽

10.1557/jmr.2009.0428 ◽

2009 ◽

Vol 24 (12) ◽

pp. 3653-3663 ◽

Cited By ~ 6

Author(s):

Taihua Zhang ◽

Peng Jiang ◽

Yihui Feng ◽

Rong Yang

Keyword(s):

Numerical Experiments ◽

Spherical Indentation ◽

Numerical Verification ◽

Instrumented Indentation ◽

Plastic Properties ◽

Wide Range ◽

Validity Range ◽

Indentation Tests ◽

Properties Of Materials ◽

Indentation Methods

Instrumented indentation tests have been widely adopted for elastic modulus determination. Recently, a number of indentation-based methods for plastic properties characterization have been proposed, and rigorous verification is absolutely necessary for their wide application. In view of the advantages of spherical indentation compared with conical indentation in determining plastic properties, this study mainly concerns verification of spherical indentation methods. Five convenient and simple models were selected for this purpose, and numerical experiments for a wide range of materials are carried out to identify their accuracy and sensitivity characteristics. The verification results show that four of these five methods can give relatively accurate and stable results within a certain material domain, which is defined as their validity range and has been summarized for each method.

Download Full-text

Determination of the Elastic-Plastic Properties of 15Kh2MFA Steel with Austenitic Cladding

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.586.43 ◽

2013 ◽

Vol 586 ◽

pp. 43-46 ◽

Cited By ~ 2

Author(s):

Aleš Materna ◽

Jiri Nohava ◽

Petr Haušild ◽

Vladislav Oliva

Keyword(s):

Tensile Test ◽

Indentation Test ◽

Strain Curve ◽

Indentation Load ◽

Spherical Indentation ◽

Compression Tests ◽

Material Interface ◽

Plastic Properties ◽

Longitudinal Orientation ◽

Sufficient Distance

The spherical indentation response of pressure vessel reactor steel with austenitic cladding is investigated both experimentally and numerically. The instrumented indentation test was performed for both materials at a sufficient distance from the bi-material interface, thus the results can be compared with the bulk data obtained from the standard tensile and compression tests. The stress – plastic strain curve for austenitic cladding estimated by a simplified inverse analysis of the indentation load – penetration curve is shifted to a harder response compared with that determined from the tensile test. One of the possible reasons, anisotropy of the cladding metal, was experimentally observed during the compression tests performed in the longitudinal orientation of the tensile test specimens and in the transverse orientation identical with the direction of the material indentation.

Download Full-text

Local Mechanical Characterization of Metal Foams by Nanoindentation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.662.59 ◽

2015 ◽

Vol 662 ◽

pp. 59-62 ◽

Cited By ~ 2

Author(s):

Jiří Němeček ◽

Vlastimil Kralik

Keyword(s):

Cell Walls ◽

Plastic Material ◽

Spherical Indentation ◽

Isotropic Hardening ◽

Plastic Properties ◽

Macro Scale ◽

Static Indentation ◽

Indentation Tests ◽

Constitutive Parameters

This paper deals with microstructure and micromechanical properties of two commercially available aluminium foams (Alporas and Aluhab). Since none of the materials is available in a bulk and standard mechanical testing at macro-scale is not possible the materials need to be tested at micro-scale. To obtain both elastic and plastic properties quasi-static indentation was performed with two different indenter geometries (Berkovich and spherical tips). The material phase properties were analyzed with statistical grid indentation method and micromechanical homogenization was applied to obtain effective elastic wall properties. In addition, effective inelastic properties of cell walls were identified with spherical indentation. Constitutive parameters related to elasto-plastic material with linear isotropic hardening (the yield point and tangent modulus) were directly deduced from the load–depth curves of spherical indentation tests using formulations of the representative strain and stress introduced by Tabor.

Download Full-text