Y. Solyaev | Searcharxiv

arXiv2026

Displacement general solutions in strain gradient elasticity: review and analysis

In this work, we provide an overview of general solutions for displacement fields in static problems of isotropic strain gradient elasticity (SGE). We not only review existing solutions but also derive new representations, showing that all classical elasticity solutions - including those of Boussinesq-Galerkin, Papkovich-Neuber, Naghdi, Lame, Love and Boussinesq - can be simply generalized to SGE framework. In general, it is shown that SGE enables the use of any classical general solution representation combined with a Helmholtz decomposition for the gradient part of the displacement field. Consistency is also established between the presented Papkovich-Neuber representation and the general solutions of SGE proposed previously by Mindlin (1964), Lurie et al. (2006) and Charalambopoulos et al. (2020). Furthermore, we establish the relationships between the stress functions of different general solutions and show their completeness.

cond-mat.other↗

arXiv2025

On the influence of powder particle size on single-track formation in laser powder bed fusion of AlSi10Mg alloy

In this paper, we present the results of single-track experiments conducted for different fractions of standard AlSi10Mg powder, which were sieved to achieve varying mean size of the particles. We observed strong differences in the melting behaviour of fractions at relatively low levels of input energy in laser powder bed fusion (LPBF) process. Namely, the remarkable particle size effect arises for the position of lack of fusion boundary, i.e. for the range of process parameters where the laser power becomes sufficient for complete through-thickness melting of the powder layer at given laser scanning speed. We established that this boundary corresponds to an approximately constant linear energy density at low levels of Peclet number (Pe < 2), while the constant enthalpy density defines this boundary at the higher levels (Pe > 2). Specifically, when the mean particle size ranges from 28 to 64 microns, the required linear energy density for stable track formation ranges from 50 to 167 J/m and the nominal enthalpy density ranges from 4.4 to 15 J/mm^3. Based on the scaling law analysis and numerical simulations, we show that observed phenomena can be attributed to the change of absorptivity of powder layer, which depends on particle size and packing density. Also, we show that the values of absorptivity identified based on the analysis of position of lack of fusion boundary (0.13-0.38 for powder size 64-28 microns) correlate well with those found from the analysis of melt pool width in the formed single-tracks.

cond-mat.other↗