We present a novel approach for identifying a multiaxial thermodynamic magneto-mechanical constitutive law by direct bi- or trivariate spline interpolation from available magnetization and magnetostriction data. Reference data are first produced with a multiscale model in the case of a magnetic field and uniaxial and shear stresses. The thermodynamic model fits well to the results of the multiscale model, after which the models are compared under complex multiaxial loadings. A surprisingly good agreement between the two models is found, but some differences in the magnetostrictive behaviour are also pointed out. Finally, the model is fitted to measurement results from an electrical steel sheet. The spline-based constitutive law overcomes several drawbacks of analytical approaches used earlier. The presented models and measurement results are openly available.
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http://dx.doi.org/10.1098/rspa.2018.0280 | DOI Listing |
Adv Model Simul Eng Sci
January 2025
Department of Mechanical and Process Engineering, Institute for Mechanical Systems, ETH Zürich, Zürich, 8092 Switzerland.
We extend (EUCLID Efficient Unsupervised Constitutive Law Identification and Discovery)-a data-driven framework for automated material model discovery-to pressure-sensitive plasticity models, encompassing arbitrarily shaped yield surfaces with convexity constraints and non-associated flow rules. The method only requires full-field displacement and boundary force data from one single experiment and delivers constitutive laws as interpretable mathematical expressions. We construct a material model library for pressure-sensitive plasticity models with non-associated flow rules in four steps: (1) a Fourier series describes an arbitrary yield surface shape in the deviatoric stress plane; (2) a pressure-sensitive term in the yield function defines the shape of the shear failure surface and determines plastic deformation under tension; (3) a compression cap term determines plastic deformation under compression; (4) a non-associated flow rule may be adopted to avoid the excessive dilatancy induced by plastic deformations.
View Article and Find Full Text PDFLangmuir
January 2025
Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Surface-active agents (surfactants) release potential energy as they migrate from one of two adjacent fluids onto their fluid-fluid interface, a process that profoundly impacts the system's energy and entropy householding. The continuum thermodynamics underlying such a surfactant-enriched binary-fluid system has not yet been explored comprehensively. In this article, we present a mathematical description of such a system, in terms of balance laws, equations of state, and permissible constitutive relations and interface conditions, that satisfies the first and second law of thermodynamics.
View Article and Find Full Text PDFMath Mech Solids
January 2025
McMaster University, Hamilton, ON, Canada.
This paper deals with mesoscale analysis of masonry structures, which involves fracture propagation in brick units as well as along the masonry joints. The brick-mortar interfaces are incorporated in standard finite elements by employing a constitutive law with embedded discontinuity. Macrocracks in bricks are modelled in a discrete way using the same methodology, without any a-priori assumptions regarding their orientation.
View Article and Find Full Text PDFSci Rep
January 2025
Beijing Solidwel Intelligent Technology Co., Ltd., BeiJing, 100000, China.
Based on the Johnson-Cook constitutive model and modified Coulomb's law, the study investigates the impact of various process parameters on the weld temperature field in high-strength 5052 aluminum alloy friction stir welding (FSW) for aerospace applications. Utilizing a thermo-mechanical model, the significance of rotational speed, welding speed, and indentation on the peak weld temperature is examined through Taguchi's orthogonal experimental design. S/N ratio and ANOVA results show that the rotational speed has the most significant effect on the peak temperature of the weld, followed by the amount of indentation, and the welding speed has the smallest effect, the optimal combination of welding process parameters is determined as follows:the rotational speed is 1000 rpm, the amount of indentation is 0.
View Article and Find Full Text PDFParasit Vectors
December 2024
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany.
Background: Anthelmintic resistance in ruminants is a widespread problem that has a severe impact on productivity and animal welfare. The helminth Haemonchus contortus is generally considered the most important parasite in small ruminants due to its high pathogenicity and the widespread occurrence of anthelmintic resistance in it. Although the molecular mechanisms associated with resistance against the anthelmintics benzimidazoles (BZs) and levamisole are relatively well understood, the resistance mechanisms against the widely used anthelmintic macrocyclic lactones (MLs) ivermectin (IVM) and moxidectin (MOX) remain poorly understood.
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