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The hardness properties of materials are tracked from early history until the present time. Emphasis is placed on the hardness test being a useful probe for determining the local elastic, plastic and cracking properties of single crystal, polycrystalline, polyphase or amorphous materials. Beginning from connection made between individual hardness pressure measurements and the conventional stress–strain properties of polycrystalline materials, the newer consideration is described of directly specifying a hardness-type stress–strain relationship based on a continuous loading curve, particularly, as obtained with a spherical indenter. Such effort has received impetus from order-of-magnitude improvements in load and displacement measuring capabilities that are demonstrated for nanoindentation testing. Details of metrology assessments involved in various types of hardness tests are reviewed. A compilation of measurements is presented for the separate aspects of Hertzian elastic, dislocation-mechanics-based plasticity and indentation-fracture-mechanics-based cracking behaviors of materials, including elastic and plastic deformation rate effects. A number of test applications are reviewed, most notably involving the hardness of thin film materials and coatings.

An Eshelby particle-compounded model was employed to investigate the stress distribution in the SiCp/Fe composites during straining in order to predict the stress-strain curves of the composites. Effect of the SiC volume content and aspect ratios on yield strength of the SiCp/Fe composites was studied by the simulation. The modeling results indicate that the stress in the iron matrix is much smaller than that in SiC particles as straining the composites, which means the strengthening mechanisms of the SiCp/Fe composites is determined by the load transfer mechanisms. The aspect ratios of the particles play a significant role in yield strength of the SiCp/Fe composites especially as the particle volume content is large. The stress in SiC particles has a stronger dependence on the aspect ratios of the particles only if the reinforcement volume content is small.

Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress–strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress–strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering.

This paper focuses on the material characterization of the A356-T6 aluminum alloy wheel, which is mandatory when an experimental correlation is required with respect to the finite element analysis performed. There is always a chance that the finite element analysis results differ from experimental results if the material properties used for analysis are not developed from the component due to variation in the manufacturing processes and chemical compositions. Hence, the procedure for developing material data is presented, and the respective applicable standards are mentioned. The method of generating a stress–strain curve from the specimens extracted from the alloy wheel is presented. Finite element analysis is performed for impact loads using the developed material stress–strain curve and reference material of the same composition and heat treatment process. The finite element results for both the materials are compared to study the variations.

Hoek-Brown criterion is provided in FLAC3D software, but it is rarely applied. The main reasons is that the corresponding post -peak parameters are difficult to obtain. In the article aiming at Hoek-Brown criterion, evolution of different strength parameters and the corresponding stress-strain curves are studied by means of numerical analysis. Results show that the post-peak part of the stress-strain curve is much influenced by the evolution process of strength parameters and the confining pressure. The presented study may provide a heuristic method to determine the law of post-peak evolution of strength parameters of Hoek-Brown criterion.