Zhaohe Dai^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09223

Abstract The flexible and clinging nature of ultra-thin films require the understanding of their elastic and adhesive properties in a wide range of circumstances from fabrications to applications. Simultaneously measuring both properties, however, is extremely difficult as the film thickness diminishes to nanoscales. In this talk, I will show our recent work that addresses such difficulties through peeling by vertically pulling thin films off from the substrates (we thus refer to it as “pull-to-peel”). Particularly, we perform in-situ pull-to-peel of graphene and MoS2 films in a scanning electron microscope and achieve simultaneous determination of their Young’s moduli and adhesions to gold… More >

Enzoh Langi¹, Liguo Zhao^2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010163

Abstract Additive manufacturing emerges as an innovative technology to fabricate medical stents used to treat blocked arteries. However, there is a lack of study of underlying microstructure and mechanical properties of additively manufactured stent. In this work, additively manufactured 316L stainless steel stent was investigated, with electrochemical polishing being used to improve the surface finish. Microstructural characterisation was carried out using optical microscopy, scanning electron microscopy, and electron backscatter diffraction. The hardness and elastic modulus were measured using Berkovich nanoindentation, with an emphasis on the effect of grain orientation. In addition, spherical nanoindentation was used to obtain indentation stress-strain curves based… More >

Zhihai He^1,2, Menglu Shen¹, Jinyan Shi^3,*, Jingyu Chang¹, Víctor Revilla-Cuesta⁴, Osman Gencel⁵

Journal of Renewable Materials, Vol.11, No.4, pp. 1835-1852, 2023, DOI:10.32604/jrm.2023.024887

Abstract Recycling solid waste in cement-based materials cannot only ease its load on the natural environment but also reduce the carbon emissions of building materials. This study aims to investigate the effect of recycled glass powder (RGP) on the early-age mechanical properties and autogenous shrinkage of cement pastes, where cement is replaced by 10%, 20% and 30% of RGP. In addition, the microstructure and nano-mechanical properties of cement paste with different RGP content and water to binder (W/B) ratio were also evaluated using SEM, MIP and nanoindentation techniques. The results indicate that the early-age autogenous shrinkage decreases with the increase of… More > Graphic Abstract

VAN-CHIEN BUI^*

BIOCELL, Vol.46, No.7, pp. 1629-1632, 2022, DOI:10.32604/biocell.2022.018364

Abstract Microenvironment contains biophysical and biochemical elements to maintain survival, growth, proliferation, and differentiation of cells. Any change can lead to cell response to the mechanical forces, which can be described by elasticity. It is an indicator of a cell’s state since it plays an important role in many cellular processes. In many cases, cell elasticity is measured by using discontinuous manner, which may not allow elucidating real-time activity of individual live cells in physiological condition or cell response against microenvironmental changes. I argue that measuring cell elasticity using continuously repetitive nanoindentation technique is important that should be considered. As an… More >

Shaoxiang Cai¹, Yuliang Guo¹, Yanjun Li^2,*

Journal of Renewable Materials, Vol.10, No.1, pp. 119-133, 2022, DOI:10.32604/jrm.2022.016260

Abstract In this study, Pinus massoniana Lamb at different heights, across the annual rings, and between earlywood and latewood was measured by X-ray diffraction and the chemical composition was analyzed by chemical treatment. Results indicated that the microfibril angle (MFA) decreased and the chemical composition changed little with the increase in height from 1 m to 9 m. In the radial direction, the MFA decreased and the chemical composition changed little with an increase in annual rings. The cellulose content of latewood was higher than that of earlywood. The viscoelastic changes of wood cell walls at different heights, across the annual rings by… More >

Jian Chen¹, Huang Yuan², Folker H. Wittmann³

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 743-754, 2002, DOI:10.3970/cmes.2002.003.743

Abstract Experimental observation confirms that micro-hardness of metallic materials depends significantly on the indentation depth. In the present paper we discuss simulations of micro-indentation tests based on the gradient plasticity model using the finite element method. The role of intrinsic material length parameters in the gradient plasticity model is investigated. The computational results confirm that the gradient plasticity model is suitable to simulate micro-indentation tests and predicts the depth-dependent hardness in micro- and nano-indentations. Variations of micro-hardness is correlated with the intrinsic material length parameters. More >

Xiuqing Qian, Yanping Cao, Kunya Zhang, Zhicheng Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.4, pp. 129-130, 2011, DOI:10.3970/icces.2011.017.129

Abstract Depth-sensing instrumented indentation tests are widely used to probe the mechanical properties of materials at a local area and small scales. Generally, indented solid was assumed semi-infinite plane solid because the contact region is small comparing the indented solid. However, for some biomaterial, such as skin, cornea and sclera, the effect of the curvature of the surface cannot be ignored. Using systematic finite element analysis and dimensional analysis, a method to determine the elastic modulus of the materials with curved surface is proposed using flat punch indentation in this paper.

An axisymmetric, two-dimensional model was adopted and four-node bilinear… More >

Xiaozhi Tang, Yafang Guo, Yu Gao

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 25-26, 2011, DOI:10.3970/icces.2011.020.025

Abstract Atomistic simulations were performed to study the nano-indentation for two kinds of FCC metals, aluminum and copper. Two different deformation mechanisms were observed in our simulation under exactly the same simulation condition. An embedded atom method potential was employed for copper and a generalized form of EAM potential due to Finnis and Sinclair for aluminum. In the simulation model, the substrate was constructed with 78408 atoms in an 8I?*40I?*60I? cell, here I? means the lattice constant. The indenter was modeled by a cubic with its side length of 8a.During the simulation, the period boundary condition was applied to the (1… More >

Yan-ping CAO, Xiu-qing Qian, Norbert Huber

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 17-18, 2011, DOI:10.3970/icces.2011.019.017

Abstract In the development of a systematic method to determine the mechanical properties of materials using depth-sensing instrumented indentation tests, a key issue is to find the connection between the indentation response and the properties of the indented material. For spherical indentation into power law engineering materials, we showed that this problem can be solved by using the concept of the representative strain. In the present research, using finite element analysis based on the incremental plasticity theory and large deformation formulations, we proposed four indentationresponse based definitions of the representative strain. Each of them leads to a simple and explicit expression… More >

Q. Ma^1,2, J. L. Beuth¹, G. H. Meier³, F. S. Pettit³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 13-18, 2008, DOI:10.3970/icces.2008.008.013

Abstract This paper addresses the mechanics of indentation-induced delamination of a coating on a multi-layered hollow cylinder, for application to toughness testing of thermal barrier coating (TBC) systems. An electron-beam physical vapor deposition (EB-PVD) TBC system has been analyzed through a contact finite element model using a standard conical indenter impressed vertically on the top of the cylinder. Two cylinder sizes used in thermal-mechanical fatigue tests in literature have been considered in the analysis, with outer radii of 5.11 mm and 3.08 mm, and inner radii of 3.00 mm and 0.97 mm, respectively. Two boundary conditions for the inner surface of… More >