Load identification for full-field reconstruction: applications to plates under tension loads

• Published in: International journal for numerical methods in engineering Vol. 91; no. 10; pp. 1073 - 1086
• Main Authors: Martini, D., Hochard, Ch, Charles, J.-P.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 07.09.2012; Wiley
• Subjects: Engineering Sciences; Exact sciences and technology; Fundamental areas of phenomenology (including applications); inverse problems; Materials and structures in mechanics; Mechanics; Mechanics of materials; Physics; plates; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; structural monitoring; Trefftz method; Vibrations; Performance evaluation; Saint Venant principle; Trefftz method; plates; Perforated plate; Mechanical properties; Boundary condition; Real time; Modeling; Steady state; Inverse problem; Deformation measurement; Overload; structural monitoring; inverse problems; Ill posed problem; Signal reconstruction; System identification; Monitoring
• ISSN: 0029-5981; 1097-0207
• DOI: 10.1002/nme.4304

SUMMARY The full‐field reconstruction method presented here is suitable for real‐time structural monitoring purposes, such as improving the performances of structures. The aim is to characterize mechanical fields and boundary conditions while the structure is in service, using just a few on‐line measurements. This characterization is an ill‐posed inverse problem, the solution of which requires making some prior assumptions. The structures studied are assumed to be in steady‐state configurations and to show linear mechanical behavior, and the loading zones are assumed not to be overstressed; the mechanical fields are monitored only inside the structures. The full‐field identification is regularized using the boundary conditions, which are identified from strain measurements, and the mechanical fields are then reconstructed from these identified boundary conditions. On the basis of Saint‐Venant's principle, the boundary conditions are approximated with a few parameters, the basis functions of which are obtained from the projections of Trefftz‐like solutions onto the boundaries of the structures. These approximate boundary conditions are linked to the global mechanical responses of the structures. Lastly, this full‐field reconstruction method is applied to plate‐like structures with holes subjected to in‐plane loads. The results show that the load identification procedure efficiently regularizes the full‐field reconstruction method, and that this method is suitable for structural monitoring purposes. The sensitivity of this method to errors is similar to that of the load identification procedure, and the maximum errors in the solutions are located at the boundaries. Copyright © 2012 John Wiley & Sons, Ltd.