analytical solution, Fourier cosine series, vibrations, FGM rectangular plates, Mindlin plate theory, phased array transducer, transducer optimization, beam focusing, pulse–echo mode, harmonic generation, stress-free boundary, total correction, acoustic emission, electrical resistance, damage monitoring, criticality, natural time analysis, nonlinear parameter, noncontact reception, air-coupled receiver, aluminum samples, corrections, field theory, deformation and fracture, 7075 aluminum alloy, electronic speckle pattern interferometry, concrete beam, bending, cementitious matrix, FRCM, analytical model, numerical model, linear low-density polyethylene, digital image correlation, optical non-destructive testing, speckle, fourier scaling theorem, gaussian filtering, optical methods, AlSi10Mg, SLM, NDE, deep learning, CNN, k-fold cross validation, non-destructive testing, optical interferometry, residual stress, thermal expansion, elasticity, high entropy alloys, complex concentrated alloys, refractory metal intermetallic composites, high entropy phases, complex concentrated phases, Nb silicide-based alloys, alloy design, biomechanics, Achilles tendon, beam-to-beam contact, arbitrary cross-section, ANCF, lithium-ion batteries, redox-active organic anode, organic anode materials, Research and information: general, Physics

Modern materials and structures are significantly different from conventional ones. Their sizes can be orders of magnitude smaller, and their compositions are so sophisticated that traditional characteristic methods are inapplicable. Non-conventional methods are essential to tackle these issues, which must often be approached in an interdisciplinary fashion. This Special Issue is a collection of articles that shed light on these problems.