During the single-point incremental forming (SPIF) process, a sheet is formed by a locally acting stress field on the surface consisting of a normal and shear component that is strongly affected by friction of the dragging forming tool. SPIF is usually performed under well-lubricated conditions in order to reduce friction. Instead of lubricating the contact surface of the sheet metal, we propose an innovative, environmentally friendly method to reduce the coefficient of friction by ultrasonic excitation of the metal sheet. By evaluating the tool-workpiece interaction process as non-linear due to large deformations in the metal sheet, the finite element method (FEM) allows for a virtual evaluation of the deformation and piercing parameters of the SPIF process in order to determine destructive loads.
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http://dx.doi.org/10.3390/ma15031024 | DOI Listing |
Ultrasonics
January 2025
Medical Ultrasound Department for the Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu 215163, China. Electronic address:
Shear Wave Elastography (SWE) is an imaging technique that detects shear waves generated by tissue excited by Acoustic Radiation Force (ARF), and characterizes the mechanical properties of soft tissue by analyzing the propagation velocity of shear wave. ARF induces a change in energy density through the nonlinear propagation of ultrasound waves, which drives the tissue to generate shear waves. However, the amplitude of shear waves generated by ARF is weak, and the shear waves are strongly attenuated in vivo.
View Article and Find Full Text PDFHeliyon
January 2025
Center for MicroElectromechanical Systems (CMEMS), University of Minho, Guimarães, 4800-058, Portugal.
Recently, Organ-on-a-Chip (OoC) platforms have arisen as an increasingly relevant experimental tool for successfully replicating human physiology and disease. However, there is a lack of a standard technology to monitor the OoC parameters, especially in a non-invasive and label-free way. Photoacoustic (PA) systems can be considered an alternative and accurate assessment method for OoC platforms.
View Article and Find Full Text PDFUltrasonics
December 2024
Faculty of Information Technology, Beijing University of Technology, Beijing, China.
The thickness loss caused by corrosion is a vital factor that threatens the health of shell structures. It is significant to perform a non-destructive quantitative evaluation of corrosion-thinning defects in plate structures. Based on the laser ultrasonic guided wavefield scanning technology, this paper proposes an instantaneous wavenumber multi-shot fusion method, which improves the performance of the instantaneous wavenumber imaging method.
View Article and Find Full Text PDFSci Rep
December 2024
School of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu, 610500, China.
Accurately determining the initial acoustic field excitation load of a piezoelectric ultrasonic probe is essential for simulating electrical signals and calculating wall thickness during ultrasonic internal inspection of pipelines. A new method for determining the initial excitation load of the acoustic field is proposed, incorporating the focusing effect of the curved surface of pipelines on the ultrasonic signal from the piezoelectric ultrasonic probe. Finite element models were established for the new and old methods using COMSOL software, facilitating the analysis of the initial acoustic field distribution and associated electrical signal characteristics.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
Institute for Theoretical and Applied Electromagnetics RAS, Moscow 125412, Russia; Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia.
In this study, we have investigated the surface-enhanced Raman scattering (SERS) spectra of myoglobin on silver substrates with different morphology. The aim was to determine the optimal parameters of analyte and substrate preparation for obtaining of high-amplitude SERS spectra of proteins. It is shown that not only the morphology of the silver film, but also the method of analyte molecules deposition on the SERS substrate plays an important role.
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