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 >

Haiyi Liang¹, C.H. Woo^1,2, Hanchen Huang³, A.H.W. Ngan⁴, T.X. Yu⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 105-114, 2004, DOI:10.3970/cmes.2004.006.105

Abstract Molecular dynamics (MD) simulations are performed to study crystalline plasticity during nano-indentation by comparing the elastic-plastic response of three copper substrates with surfaces (001), (110), and (111) crystallographic planes. The effects of elastic anisotropy and crystallographic symmetry on the reduced modulus, dislocation nucleation, and subsequent microstructure evolution, are investigated. The reduced modulus of (111) surface is found to be the largest, while that of (001) surface is the smallest. Elastic stress distribution calculated from finite element method (FEM) is qualitatively consistent with the MD simulation results. Significant differences exist in the deformation behavior in the three different crystallographic orientations. The… More >

G. Lasko^∗, I. Schäfer^∗, Z. Burghard^†, J. Bill^†, S. Schmauder^∗, U. Weber^∗, D. Galler^‡

Molecular & Cellular Biomechanics, Vol.10, No.1, pp. 27-42, 2013, DOI:10.3970/mcb.2013.010.027

Abstract Owing to the apparent simple morphology and peculiar properties, nacre, an iridescent layer, coating of the inner part of mollusk shells, has attracted considerable attention of biologists, material scientists and engineers. The basic structural motif in nacre is the assembly of oriented plate-like aragonite crystals with a ’brick’ (CaCO₃ crystals) and ’mortar’ (macromolecular components like proteins) organization. Many scientific researchers recognize that such structures are associated with the excellent mechanical properties of nacre and biomimetic strategies have been proposed to produce new layered nanocomposites. During the past years, increasing efforts have been devoted towards exploiting nacre’s structural design principle in… More >

X. Edward Guo^∗,†,‡, Erica Takai^∗,‡, Xingyu Jiang^§, Qiaobing Xu^§, George M. Whitesides^§, James T. Yardley^¶, Clark T. Hung^*, Eugene M. Chow^||, Thomas Hantschel^∗∗, Kevin D. Costa^∗

Molecular & Cellular Biomechanics, Vol.3, No.3, pp. 95-108, 2006, DOI:10.3970/mcb.2006.003.095

Abstract In this study, bone cells were successfully cultured into a micropatterned network with dimensions close to that of in vivo osteocyte networks using microcontact printing and self-assembled monolyers (SAMs). The optimal geometric parameters for the formation of these networks were determined in terms of circle diameters and line widths. Bone cells patterned in these networks were also able to form gap junctions with each other, shown by immunofluorescent staining for the gap junction protein connexin 43, as well as the transfer of gap-junction permeable calcein-AM dye. We have demonstrated for the first time, that the intracellular calcium response of a… More >

S. S. Pulla¹, Y. C. Lu²

CMC-Computers, Materials & Continua, Vol.29, No.3, pp. 263-278, 2012, DOI:10.3970/cmc.2012.029.263

Abstract The nanoindentation technique is used to quantify the interfaces between dissimilar materials. The interfaces can be generally referred as to the transition regions in polymers due to environmental aging, or the regions between fibers and polymer matrix in composites, or other similar situations. It is proposed to use a nanoindenter equipped with small spherical tip to cross-indent the interfaces of dissimilar materials. The nanoindentation tests were carried out through 3-dimensional finite element simulations with varying properties of the two dissimilar materials, including various combinations of modulus (E₁/E₂), yield strength (σ_y1/σ_y2), hardening index (n₁/n₂), and the interface sizes (R/T). The mechanical… More >

R. Khanna^1,2, D. R. Katti¹, K. S. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.6, pp. 530-556, 2012, DOI:10.3970/cmes.2012.087.530

Abstract Here we report a new in situ nanoindentation technique developed to evaluate the composite mechanical behavior of cell-biomaterial construct under physiological conditions over the time scale of bone nodule generation. Using this technique, mechanical behavior of osteoblast cell-substrate interfaces on tissue engineered materials (chitosan-polygalacturonic acid-nanohydroxyapatite (CPH) films) is investigated. Mechanical behavior of cells in the elastic regime over the time scale of cell adhesion (1 day), proliferation (4 days), development (8 days) and maturation (22 days) of bone nodules is evaluated. Our results indicate that the elastic properties of flat cells are higher (indicating stiffer response, after 4 days, as… More >

Taffetani M.¹, Bertarelli E.^1,2, Gottardi R.^3,4, Raiteri R.⁵, Vena P.^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.5, pp. 433-460, 2012, DOI:10.3970/cmes.2012.087.433

Abstract Dynamic nanoindentation is a novel nanomechanical testing that is being increasingly used to characterize the frequency response of viscoelastic materials and of soft hydrated biological tissues at the micrometric and nanometric length scales. This technique is able to provide more information than those obtained by simple indentation; however, its interpretation is still an open issue for complex materials such as the case of anisotropic biological tissues that generally have a high water content. This work presents a numerical model to characterize the frequency response of poro-elastic tissues subjected to harmonic indentation loading with particular regard to the effect of geometrical… More >

Jin Ma, Yang Liu, Hongbing Lu, Ranga Komanduri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.1, pp. 41-56, 2006, DOI:10.3970/cmes.2006.016.041

Abstract A multiscale simulation technique coupling three scales, namely, the molecular dynamics (MD) at the atomistic scale, the discrete dislocations at the meso scale and the generalized interpolation material point (GIMP) method at the continuum scale is presented. Discrete dislocations are first coupled with GIMP using the principle of superposition (van der Giessen and Needleman (1995)). A detection band seeded in the MD region is used to pass the dislocations to and from the MD simulations (Shilkrot, Miller and Curtin (2004)). A common domain decomposition scheme for each of the three scales was implemented for parallel processing. Simulations of indentation were… More >