Full-field full-stress-tensor identification of base-excited structures

Šonc, Jaša (avtor), Zaletelj, Klemen (avtor), Slavič, Janko (avtor)

Identifying the full-stress tensor over the surface of a vibrating structure is essential for design validation and vibration-fatigue-life estimation, yet current experimental methods provide only pointwise or incomplete stress data. Infrared cameras can provide non-contact, full-field surface-stress measurements on vibrating structures via the thermoelastic effect; however, they measure only the first stress invariant (i.e., the sum of the normal stresses at the free surface: σ$_{xx}$ + σ$_{yy}$). The individual stress components (σ$_{xx}$, σ$_{yy}$, τ$_{xy}$) required for a complete characterisation of the surface-stress state remain inaccessible from a single thermoelastic measurement. This article introduces a method that recovers the full-field, in-plane-stress power spectral density (PSD) field from thermoelastic camera data on a base-excited structure, demonstrated for thin, isotropic, metallic, plate-like structures under adiabatic conditions. First, a characterisation measurement identifies the hybrid stress-mode shapes containing all the plane-stress components by merging thermoelastic camera data with a simplified FE model through SEMM. Then, during operation under broadband random base excitation, the camera response is projected onto these mode shapes and expanded to the full-stress-tensor PSD. The method is validated experimentally on a clamped aluminium plate, identifying spatially resolved stress PSDs for all three in-plane components (σ$_{xx}$, σ$_{yy}$, τ$_{xy}$). The full-field first invariant σ$_{xx}$ + σ$_{yy}$ is measured experimentally; the individual components σ$_{xx}$, σ$_{yy}$ and τ$_{xy}$ are reconstructed through an experimentally corrected modal expansion informed by an FE stress basis, which supplies the inter-component ratios.

• Jezik: Angleški jezik
• Ključne besede: thermoelastic stress analysis, power spectral density, multiaxial vibration fatigue, SEMM, modal expansion, infrared camera
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: 24 str.
• Številčenje: Vol. 259, art. 114786
• PID: 20.500.12556/RUL-189537
• UDK: 534:620.178.3
• ISSN pri članku: 0888-3270
• DOI: 10.1016/j.ymssp.2026.114786
• COBISS.SI-ID: 294297603
• Datum objave v RUL: 08.10.2026

Gradivo je del revije

• Naslov: Mechanical systems and signal processing
• Skrajšan naslov: Mech. syst. signal process.
• Založnik: Academic Press
• ISSN: 0888-3270
• COBISS.SI-ID: 169243

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: termoelastična analiza napetosti, spektralna gostota moči, večosno vibracijsko utrujanje, SEMM, modalna ekspanzija, infrardeča kamera

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P2-0263
• Naslov: Mehanika v tehniki