Damage Localization and State Space Identification Based on Noisy Observations, H-infinity Estimation Theory and Subspace Methods during Lifetime of Non-Stationary, Mechanical Structures using Ambient Excitation

• Applicant: Professor Dr.-Ing. Armin Lenzen
• Subject Area: Applied Mechanics, Statics and Dynamics ; Mechanics
• Term: from 2017 to 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 350257805

• Final Report Year: 2025

Final Report Abstract

Modeling technical structures is an important component throughout the entire life cycle of a mechanical structure (planning, construction, use, and dismantling) and a tool for engineers to make sound analyses and decisions. Finite element methods of structural mechanics are traditionally used here. For measurement-data-driven identification methods, the inherent high parameter diversity of FEM often leads to unfavorable mathematical problems. This research demonstrates that, during the maintenance phase, the identification of ambiently excited mechanical structures as a black-box model, due to its low model order, can be used very advantageously for automated and real-time condition identification and damage localization. Many methods have been developed for damage detection, but damage localization, given the mandatory consideration of environmental and operational influences, is an important, current, and internationally unsolved field of research. Therefore, this problem is the focus of this work. Using numerical algebraic optimization methods from estimation theory, which were still unknown in structural mechanics, a fundamentally new methodology for damage identification was theoretically prepared in the research work and experimentally verified on a pilot plant as well as on a real mechanical structure under operating conditions from the field of infrastructure.

Publications

• An output-only damage identification method based on H∞ theory and state projection estimation error (SP2E). Structural Control and Health Monitoring, 24(11), e2003.
  Lenzen, Armin & Vollmering, Max
  
• Experimentelle Schadenslokalisation auf Basis der H∞-Schätztheorie und State Projection Estimation Error. Baudynamik 2018, 159-168. VDI Verlag.
  Vollmering, M. & Lenzen, A.
  
• On experimental damage localization by SP2E: Application ofH^(∞)estimation and oblique projections. Mechanical Systems and Signal Processing, 104, 648-662.
  Lenzen, Armin & Vollmering, Max
  
• Theory and numerical application of damage localization method state projection estimation error (SP2E). Structural Control and Health Monitoring, 25(10), e2237.
  Vollmering, Max & Lenzen, Armin
  
• Schädigungserkennung in mechanischen Strukturen mithilfe der Stochastic Subspace Identification und der Kreinraum-basierten H-∞ Schätztheorie. Bauingenieur, 94(10), S 15-S 17.
  Lenzen, Armin & Vollmering, Max
  
• AN IN-SITU EXPERIMENTAL SETUP FOR DAMAGE LOCALIZATION AND MECHANICAL PARAMETER ESTIMATION. Proceedings of the XI International Conference on Structural Dynamics, 857-869. EASD.
  Vollmering, Max; Dolbonosov, Ivan & Lenzen, Armin
  
• Mechanical system scaling based on output only identification and mass perturbations by state projections. Mechanical Systems and Signal Processing, 144, 106863.
  Lenzen, Armin & Vollmering, Max
  
• “Normierung der Output-Only-Methode zur Identifikation mechanischer Systeme“ Baustatik Baupraxis 14, Universität Stuttgart
  Lenzen, Armin
  
• Damage localization of mechanical structures considering environmental and operational conditions based on output-only system identification and H∞-estimation. Mechanical Systems and Signal Processing, 156, 107572.
  Lenzen, Armin; Rohrer, Maximilian & Vollmering, Max
  
• Estimation of mechanical parameters based on output-only measurements using Kronecker product equivalence and mass perturbations. Journal of Sound and Vibration, 500, 116016.
  Vollmering, Max; Breitkreuz, Maximilian & Lenzen, Armin
  
• Modellorientierte Schadenslokalisation von mechanischen Strukturen unter Einbeziehung der Umgebungs- und Betriebsbedingungen. Baudynamik 2022, 221-232. VDI Verlag.
  Rohrer, M. & Lenzen, A.
  
• Modulares Experimentierfeld des I4S an der HTWK Leipzig. Bauingenieur, 97(06), S 6-S 7.
  Lenzen, Armin; Moeller, Max & Rohrer, Maximilian
  
• Modulares Experimentierfeld zur Verifikation der Schadenslokalisation an einer realen mechanischen Struktur. Baudynamik 2022, 463-476. VDI Verlag.
  Moeller, M. & Lenzen, A.
  
• A Testing Field for Studies of Environmental and Operational Effects in Structural Damage Localization of Mechanical Structures. Structural Control and Health Monitoring, 2024(1).
  Rohrer, Maximilian; Moeller, Max & Lenzen, Armin
  
• Experimental vibration-based output-only damage localization of mechanical systems. e-Journal of Nondestructive Testing, 29(7).
  Rohrer, Maximilian; Moeller, Max & Lenzen, Armin
  
• Neuartige Konzepte für die Zustandsüberwachung und -analyse von Brückenbauwerken – Einblicke in das Forschungsvorhaben SPP100+/Novel Concepts for the Condition Monitoring and Analysis of Bridge Structures – Insights into the SPP100+ Research Project. Bauingenieur, 99(10), 327-338.
  Becks, Henrik; Lippold, Lukas; Winkler, Paul; Moeller, Max; Rohrer, Maximilian; Leusmann, Thorsten; Anton, David; Sprenger, Bjarne; Kähler, Philipp; Rudenko, Iryna; Arcones, Daniel Andrés; Koutsourelakis, Phaedon-Stelios; Unger, Jörg F.; Weiser, Martin; Petryna, Yuri; Schnellenbach-Held, Martina; Lowke, Dirk; Wessels, Henning; Lenzen, Armin ... & Hegger, Josef
  
• Schadenserkennung an Baukonstruktionen mit intelligenten Methoden der Systemidentifikation. Informatik Festival 2024, Wiesbaden, Germany, September 24-26, 2024
  Armin Lenzen, Max Moeller & Maximilian Rohrer
  
• System identification and monitoring of bridge structures. Procedia Structural Integrity, 64, 1256-1263.
  Rohrer, Maximilian; Moeller, Max & Lenzen, Armin
  
• System identification based on the cross Gramian. e-Journal of Nondestructive Testing, 29(7).
  Moeller, Max; Rohrer, Maximilian & Lenzen, Armin
  
• „Monitoring an der Floßgrabenbrücke in Zeitz - Experimente zur Systemidentifikation,“ in Berichte der Fachtagung "Baustatik - Baupraxis 15", 04. und 05. März 2024, Hamburg
  A. Lenzen, M. Moeller & M. Rohrer
  
• Autonomous energy-based model order selection in parameter state space identification via cross Gramian and symmetrizer. Mechanical Systems and Signal Processing, 228, 112452.
  Moeller, Max & Lenzen, Armin
  
• Experimental studies on multi‐scale data‐driven methods within the framework of structural health monitoring. Civil Engineering Design, 7(4), 147-168.
  Rohrer, Maximilian; Backhaus, Jan; Bestmann, Ulf; De Arriba López, Vanessa; Diaz, Pedro Achanccaray; Gerke, Markus; Könke, Carsten; Lenzen, Armin; Lippold, Lukas; Maboudi, Mehdi; Moeller, Max; Villegas, Carlos Luis Paz; Winkler, Paul & Zabel, Volkmar
  
• Langzeitüberwachung mittels autonomer Systemidentifikation. Baudynamik 2025, 201-212. VDI Verlag.
  Moeller, M. & Lenzen, A.
  
• Systemidentifikation und Zustandsüberwachung der Flossgrabenbrücke System identification and structural health monitoring of the Flossgraben Bridge. Baudynamik 2025, 225-236. VDI Verlag.
  Rohrer, M. & Lenzen, A.