Determination of an Objective Criterion for the Assessment of the Feasibility of an Instrumented Indentation Test on Rough Surfaces.

Materials (Basel)

Laboratoire d'Automatique, de Mécanique et d'Informatique industrielle et Humaine (LAMIH) UMR-CNRS 8201, Université Polytechnique des Hauts de France, Le Mont Houy, 59313 Valenciennes, France.

Published: March 2020

The influence of roughness on the results of indentation testing was investigated using a semianalytical model. This model used simulated surfaces that were described using three standard roughness parameters: the root-mean-square deviation S, the wavelength (or cut-off of Gaussian high-pass filter), and the fractal dimension. It was shown that S had the largest effect on the determination of the macrohardness, while the surface wavelength and fractal dimension had negligible effects at the scale of investigation. The error of determination of the macrohardness rose with the increase of the ratio S/h where h was the maximum indentation depth: S/h ratios lower than 0.02 were required to obtain a systematic error of the macrohardness lower than 5%, whatever the examined material mechanical properties (in elasticity and plasticity).

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7178069PMC
http://dx.doi.org/10.3390/ma13071589DOI Listing

Publication Analysis

Top Keywords

fractal dimension
8
determination macrohardness
8
determination objective
4
objective criterion
4
criterion assessment
4
assessment feasibility
4
feasibility instrumented
4
instrumented indentation
4
indentation test
4
test rough
4

Similar Publications

The topology of a chaotic attractor in the Kuramoto-Sivashinsky equation.

Chaos

January 2025

Emergent Complexity in Physical Systems Laboratory (ECPS), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.

The Birman-Williams theorem gives a connection between the collection of unstable periodic orbits (UPOs) contained within a chaotic attractor and the topology of that attractor, for three-dimensional systems. In certain cases, the fractal dimension of a chaotic attractor in a partial differential equation (PDE) is less than three, even though that attractor is embedded within an infinite-dimensional space. Here, we study the Kuramoto-Sivashinsky PDE at the onset of chaos.

View Article and Find Full Text PDF

Mechanism analysis for the differences in multi-level structure, enzyme accessibility and pasting properties of starch granules caused by different hydrolysis pathways of maltogenic α-amylase.

Food Chem

January 2025

State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China.

The effect of pores distribution on the multi-scale structure, enzyme accessibility, and pasting properties of the waxy maize starch granules with the same degree of hydrolysis were examined. Increased maltogenic α-amylase (MA) dosage obviously increased the shallow pores number and the roughness, whereas extended time increased the holes depth. Despite achieving the same hydrolysis degree and specific surface area, samples with numerous shallow holes exhibited a higher mass fractal dimension, a lower, peak viscosity, final viscosity and setback.

View Article and Find Full Text PDF

Aims: The aim of this study was to investigate the effect of two different bisphosphonate types on bone using dental panoramic radiographs (DPRs) and to compare these findings with a healthy cohort.

Study Design: Panoramic dental radiographs of bisphosphonate users (30) and healthy individuals (30) were retrospectively evaluated for the study. Regarding FA, standardized 50 × 50 pixel regions of interest (ROI) were identified for each patient.

View Article and Find Full Text PDF

Using space-filling curves and fractals to reveal spatial and temporal patterns in neuroimaging data.

J Neural Eng

January 2025

Center for Complex Systems and Brain Sciences, Universidad Nacional de San Martin Escuela de Ciencia Y Tecnologia, 25 de Mayo y Francia, San Martín, Buenos Aires, 1650, ARGENTINA.

Objective Magnetic resonance imaging (MRI), functional MRI (fMRI) and other neuroimaging techniques are routinely used in medical diagnosis, cognitive neuroscience or recently in brain decoding. They produce three- or four-dimensional scans reflecting the geometry of brain tissue or activity, which is highly correlated temporally and spatially. While there exist numerous theoretically guided methods for analyzing correlations in one-dimensional data, they often cannot be readily generalized to the multidimensional geometrically embedded setting.

View Article and Find Full Text PDF

The field of emotion recognition from physiological signals is a growing area of research with significant implications for both mental health monitoring and human-computer interaction. This study introduces a novel approach to detecting emotional states based on fractal analysis of electrodermal activity (EDA) signals. We employed detrended fluctuation analysis (DFA), Hurst exponent estimation, and wavelet entropy calculation to extract fractal features from EDA signals obtained from the CASE dataset, which contains physiological recordings and continuous emotion annotations from 30 participants.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!