Smart Technologies for Safety Engineering

This book presents the research results obtained over the last decade by the Smart Technology Centre (STC), http://smart.ippt.gov.pl/, operating at the Institute of Fundamental Technological research (IPPT) of the Polish Academy of Sciences (PAN), Warsaw, Poland. It collects achievements of several PhD theses, already completed or still being elaborated. the STC is a division of IPPT-PAN, headed by Prof. Jan Holnicki-Szulc. He graduated from the Warsaw University of Technology in civil Engineering (1969) and simultaneously from the University of Warsaw in Mathematics (1972). Hs PhD thesis (1973) and the habilitation thesis (1983) were defended in IPPT. He spent about 5 years (in the 1980s and 1990s) visiting various labs became eligible for financial support through the European research initiatives, i.e. the 4th, 5th and 6th Framework Programmes. The first PhD thesis in the STC was defended by Przemystaw Kotakowski (1998) and devoted to the application of the virtual distortion method (VDM) to optimal structural remodeling, treated as a static problem. Then, one of the next these by Tomasz G. Zielinski (2003) contained a generalization of the VDM for structural dynamics and its application to damage identification via the solution of an inverse problem. Anita Ortowska (2007) in her thesis developed an application of the dynamic VDM to the identification of delamination in composite beams. Further development of these numerical tools, allowing for fast and effective structural remodeling and solving coupled dynamic problems (including redistribution of material, stiffness and physical nonlinearity), was done by Marcin Wikto (thesis just completed). Dr Lukasz Jankowski (PhD defended in BAM, Berlin) and Dr Barttomiej Btachowski (PhD defended in IPPT-PAN, Warsaw) joined the STC in 2005 and ar4e both involved in dynamic load identification.The further development of VDM applications to the structural health monitoring (SHM) concepts and under development in collaboration with the current PhD students Andrzej Swiercz and Marek Kokot (Theses almost completed). Matgorzata Mroz (thesis in progress) is working on the application of the VDM to optimal remodeling of damping properties in dynamically excited structures. Another group of PhD students, Grzegorz Mikutowski and Piotr Pawtowski (theses almost completed), Cezary Graczykowski and Krzysztof Sekuta (theses in progress), Arkadiusz Mroz and Marian Ostrowski (theses in progress), have already obtained interesting research results in the field of adaptive impact absorption (AIA). Finally, Dr Jerzy Motylewski is a key person in the STC in vibroacoust6ic measurement techniques and hardware development.The team of seventeen co-authors is presented below; their contributions to particular chapters are listed in the Organization of the Book.

• Preface. About the Authors.Organization of the Book.1 Introduction to Smart Technologies (Jan Holnicki-Szulc, Jerzy Motylewski and Przemyslaw Kolakowski).1.1 Smart Technologies – 30 Years of History.1.2 Smart-Tech Hardware Issues.1.2.1 Structual Health Monitoring.1.2.2 Adaptive Impact Absorption.1.3 Smart-Tech Software Issues.References.2 The Virtual Distortion Method – A Versatile Reanalysis Tool (Przemyslaw Kolakowski, Marcin Wiklo and Jan Holnicki-Szulc).2.1 Introduction.2.2 Overview of Reanalysis Methods.2.3 Virtual Distortion Method – The Main Idea.2.4 VDM in Structural Statics.2.4.1 Influence Matrix in Statics.2.4.2 Stiffness Remodeling in Statics.2.4.3 Plasticity in Statics.2.4.4 Example 1 in Statics.2.4.5 Example 2 in Statics.2.5 VDM in Structural Dynamics.2.5.1 Influence Matrices in Dynamics.2.5.2 Stiffness Remodeling in Dynamics.2.5.3 Plasticity in Dynamics.2.5.4 Mass Remodeling in Dynamics.2.6 VDM-Based Sensitivity Analysis.2.7 Versatility of VDM in System Modeling.2.8 Recapitulation.2.8.1 General Remarks.2.8.2 Applications of the VDM to Structures.2.8.3 Applications of the VDM to Nonstructural Systems.References.3 VDM-Based Health Monitoring of Engineering Systems (Przemyslaw Kolakowski, Andrzej´ Swiercz, Anita Orlowska, Marek Kokot and Jan Holnicki-Szulc).3.1 Introduction to Structural Health Monitoring.3.2 Damage Identification in Skeletal Structures.3.2.1 Introduction.3.2.2 Time Domain (VDM-T) versus Frequency Domain (VDM-F).3.2.3 Modifications in Beams.3.2.4 Problem Formulation and Optimization Issues.3.2.5 Numerical Algorithm.3.2.6 Numerical Examples.3.2.7 Experimental Verification.3.2.8 Conclusions.3.3 Modeling and Identification of Delamination in Double-Layer Beams.3.3.1 Introduction.3.3.2 Modeling of Delamination.3.3.3 Identification of Delamination.3.3.4 Conclusions.3.4 Leakage Identification in Water Networks.3.4.1 Introduction.3.4.2 Modeling of Water Networks and Analogies to Truss Structures.3.4.3 VDM-Based Simulation of Parameter Modification.3.4.4 Leakage Identification.3.4.5 Numerical Examples.3.4.6 Conclusions.3.5 Damage Identification in Electrical Circuits.3.5.1 Introduction.3.5.2 Modeling of Electrical Circuits and Analogies to Truss Structures.3.5.3 VDM Formulation.3.5.4 Defect Identification.3.5.5 Numerical Example.3.5.6 Conclusions.References.4 Dynamic Load Monitoring (Lukasz Jankowski, Krzysztof Sekula, Bartlomiej D. Blachowski, Marcin Wiklo, and Jan Holnicki-Szulc).4.1 Real-Time Dynamic Load Identification.4.1.1 Impact Load Characteristics.4.1.2 Solution Map Approach.4.1.3 Approach Based on Force and Acceleration.4.1.4 Approaches Based on Conservation of Momentum.4.1.5 Experimental Test Stand.4.1.6 Experimental Verification.4.1.7 Comparison of Approaches.4.2 Observer Technique for On-Line Load Monitoring.4.2.1 State-Space Representation of Mechanical Systems.4.2.2 State Estimation and Observability.4.2.3 Model-Based Input Estimation.4.2.4 Unknown Input Observer.4.2.5 Numerical Examples.4.3 Off-Line Identification of Dynamic Loads.4.3.1 Response to Dynamic Loading.4.3.2 Load Reconstruction.4.3.3 Optimum Sensor Location.4.3.4 Numerical Example.References.5 Adaptive Impact Absorption (Piotr K. Pawlowski, Grzegorz Mikulowski, Cezary Graczykowski, Marian Ostrowski, Lukasz Jankowski and Jan Holnicki-Szulc).5.1 Introduction.5.2 Multifolding Materials and Structures.5.2.1 Introduction.5.2.2 The Multifolding Effect.5.2.3 Basic Model of the MFM.5.2.4 Experimental Results.5.3 Structural Fuses for Smooth Reception of Repetitive Impact Loads.5.3.1 Introductory Numerical Example.5.3.2 Optimal Control 1625.3.3 Structural Recovery.5.3.4 Numerical Example of Adaptation and Recovery.5.4 Absorption of Repetitive, Exploitative Impact Loads in Adaptive Landing Gears.5.4.1 The Concept of Adaptive Landing Gear.5.4.2 Control System Issues.5.4.3 Modeling of ALG.5.4.4 Control Strategies.5.4.5 Potential for Improvement.5.4.6 Fast Control of an MRF-Based Shock Absorber.5.5 Adaptive Inflatable Structures with Controlled Release of Pressure.5.5.1 The Concept of Adaptive Inflatable Structures (AIS), Mathematical Modeling and Numerical Tools.5.5.2 Protection against Exploitative Impact Loads for Waterborne Transport.5.5.3 Protective Barriers against an Emergency Crash for Road Transport.5.5.4 Adaptive Airbag for Emergency Landing in Aeronautic Applications.5.6 Adaptive Crash Energy Absorber.5.6.1 Low-Velocity Impacts.5.6.2 Energy Absorption by the Prismatic Thin-Walled Structure.5.6.3 Use of Pyrotechnic Technology for the Crash Stiffness Reduction.References.6 VDM-Based Remodeling of Adaptive Structures Exposed to Impact Loads (Marcin Wiklo, Lukasz Jankowski, Malgorzata Mróz and Jan Holnicki-Szulc).6.1 Material Redistribution in Elastic Structures.6.1.1 VDM Formulation.6.1.2 Sensitivity Analysis.6.1.3 Numerical Testing Example.6.2 Remodeling of Elastoplastic Structures.6.2.1 VDM Formulation.6.2.2 Sensitivity Analysis.6.3 Adaptive Structures with Active Elements.6.3.1 Stiffest Elastic Substructure.6.3.2 Structural Fuses as Active Elements.6.3.3 Comments.6.4 Remodeling of Damped Elastic Structures.6.4.1 Damping Model.6.4.2 General VDM Formulation.6.4.3 Specific Formulations and Sensitivity Analysis.References.7 Adaptive Damping of Vibration by the Prestress Accumulation/Release Strategy (Arkadiusz Mróz, Anita Orlowska and Jan Holnicki-Szulc).7.1 Introduction.7.2 Mass–Spring System.7.2.1 The Concept.7.2.2 Analytical Solution.7.2.3 Case with Inertia of the Active Spring Considered.7.3 Delamination of a Layered Beam.7.3.1 PAR Strategy for Layered Beams.7.3.2 Numerical Example of a Simply Supported Beam.7.3.3 PAR – the VDM Formulation.7.4 Experimental Verification.7.4.1 Experimental Set-up.7.4.2 Control Procedure.7.4.3 Results.7.5 Possible Applications.References.8 Modeling and Analysis of Smart Technologies in Vibroacoustics (Tomasz G. Zielínski).8.1 Introduction.8.1.1 Smart Hybrid Approach in Vibroacoustics.8.1.2 A Concept of an Active Composite Noise Absorber.8.1.3 Physical Problems Involved and Relevant Theories.8.1.4 General Assumptions and Some Remarks on Notation.8.2 Biot’s Theory of Poroelasticity.8.2.1 Isotropic Poroelasticity and the Two Formulations.8.2.2 The Classical Displacement Formulation.8.2.3 The Mixed Displacement–Pressure Formulation.8.3 Porous and Poroelastic Material Data and Coefficients.8.3.1 Porous Materials with a Rigid Frame.8.3.2 Poroelastic Materials.8.4 Weak Forms of Poroelasticity, Elasticity, Piezoelectricity and Acoustics.8.4.1 Weak Form of the Mixed Formulation of Poroelasticity.8.4.2 Weak Form for an Elastic Solid.8.4.3 Weak Form of Piezoelectricity.8.4.4 Weak Form for an Acoustic Medium.8.5 Boundary Conditions for Poroelastic Medium.8.5.1 The Boundary Integral.8.5.2 Imposed Displacement Field.8.5.3 Imposed Pressure Field.8.6 Interface Coupling Conditions for Poroelastic and Other Media.8.6.1 Poroelastic–Poroelastic Coupling.8.6.2 Poroelastic–Elastic Coupling.8.6.3 Poroelastic–Acoustic Coupling.8.6.4 Acoustic–Elastic Coupling.8.7 Galerkin Finite Element Model of a Coupled System of Piezoelectric, Elastic, Poroelastic and Acoustic Media.8.7.1 A Coupled Multiphysics System.8.7.2 Weak Form of the Coupled System.8.7.3 Galerkin Finite Element Approximation.8.7.4 Submatrices and Couplings in the Algebraic System.8.8 Modeling of Poroelastic Layers with Mass Implants Improving Acoustic Absorption.8.8.1 Motivation.8.8.2 Two Approaches in Modeling Small Solid Implants.8.8.3 Acoustic Absorption of the Poroelastic Layer.8.8.4 Results of Analyses.8.8.5 Concluding Remarks.8.9 Designs of Active Elastoporoelastic Panels.8.9.1 Introduction.8.9.2 Active Sandwich Panel.8.9.3 Active Single-Plate Panel.8.10 Modeling and Analysis of an Active Single-Plate Panel.8.10.1 Kinds and Purposes of Numerical Tests.8.10.2 Plate Tests.8.10.3 Multilayer Analysis.8.10.4 Analysis of Passive Behavior of the Panel.8.10.5 Test of Active Behavior of the Panel.8.10.6 Concluding Remarks.References.Acknowledgements.Index.