M H Ferri Aliabadi – författare

Structural health monitoring (SHM) is a relatively new and alternative way of non-destructive inspection (NDI). It is the process of implementing a damage detection and characterization strategy for composite structures. The basis of SHM is the application of permanent fixed sensors on a structure, combined with minimum manual intervention to monitor its structural integrity. These sensors detect changes to the material and/or geometric properties of a structural system, including changes to the boundary conditions and system connectivity, which adversely affect the system's performance.This book's primary focus is on the diagnostics element of SHM, namely damage detection in composite structures. The techniques covered include the use of Piezoelectric transducers for active and passive Ultrasonics guided waves and electromechanical impedance measurements, and fiber optic sensors for strain sensing. It also includes numerical modeling of wave propagation in composite structures. Contributed chapters written by leading researchers in the field describe each of these techniques, making it a key text for researchers and NDI practitioners as well as postgraduate students in a number of specialties including materials, aerospace, mechanical and computational engineering.

This book presents recent advances in the field of computational coupling and contact mechanics with particular emphasis on numerical formulations and methodologies necessary to solve advanced engineering applications.Featuring contributions from leading experts and active researchers in these fields who provide a detailed overview of different modern numerical schemes that can be considered by main numerical methodologies to simulate interaction problems in continuum mechanics.A number of topics are addressed, including formulations based on the finite element method (FEM) and their variants (e.g. isogeometric analysis or standard and generalized high-order FEM: hp-FEM and GFEM, respectively), the boundary element method (BEM), the material point method (MPM) or the recently proposed finite block method (FBM), among many more.Written with PhD students in mind, Advances in Computational Coupling and Contact Mechanics also includes the most recent numerical techniques which could be served as reference material for researchers and practicing engineers. All chapters are self-contained and can be read independently, with numerical formulations accompanied by practical engineering applications.Related Link(s)

In the oil and gas industries, large companies are endeavoring to find and utilize efficient structural health monitoring methods in order to reduce maintenance costs and time. Through an examination of the vibration-based techniques, this title addresses theoretical, computational and experimental methods used within this trend.By providing comprehensive and up-to-date coverage of established and emerging processes, this book enables the reader to draw their own conclusions about the field of vibration-controlled damage detection in comparison with other available techniques. The chapters offer a balance between laboratory and practical applications, in addition to detailed case studies, strengths and weakness are drawn from a broad spectrum of information.

Wear is one of the main reasons mechanical components and materials become inoperable, rendering enormous costs to society over time. Estimating wear allows engineers to predict the useful life of modern mechanical elements, reduce the costs of inoperability, or obtain optimal designs (i.e. selecting proper materials, shapes, and surface finishing according to mechanical conditions and durability) to reduce the impact of wear.Wear in Advanced Engineering Applications and Materials presents recent computational and practical research studying damage and wear in advanced engineering applications and materials. As such, this book covers numerical formulations based on the finite element method (FEM) — and the boundary element method (BEM) — as well as theoretical and experimental research to predict the wear response or life-limiting failure of engineering applications.

This book presents a guided wave-based structural health monitoring (GWSHM) system for aeronautical composite structures. Particular attention is paid to the development of a reliable and reproducible system with the capability to detect and localise barely visible impact damage (BVID) in carbon-fibre-reinforced polymer (CFRP) structures.TThe authors introduce a novel sensor installation method that offers ease of application and replacement as well as excellent durability. Electromechanical Impedance (EMI) is also explored to assess the durability of the sensor installation methods in simulated aircraft operational conditions including thermal cycles, fatigue loading, and hot–wet conditions.Damage characterisation using GWSHM is described and used to investigate damage in different CFRP structures. Key issues in guided wave-based damage identification are addressed, including wave mode and frequency selection, the influence of dynamic load, the validity of simulated damage, and the sensitivity of guided waves to impact damage in different CFRP materials.The influence of temperature on guided wave propagation in anisotropic CFRP structures is described, and a novel baseline reconstruction approach for temperature compensation is presented. Finally, a multi-level hierarchical approach for the quantification of an ultrasonic GWSHM system is put forth.

This book introduces an innovative approach to multi-fidelity probabilistic optimisation for aircraft composite structures, addressing the challenge of balancing reliability with computational cost. Probabilistic optimisation pursues statistically reliable and robust solutions by accounting for uncertainties in data, such as material properties and geometry tolerances. Traditional approaches using high-fidelity models, though accurate, are computationally expensive and time-consuming, especially when using complex methods such as Monte Carlo simulations and gradient calculations.For the first time, the proposed multi-fidelity method combines high- and low-fidelity models, enabling high-fidelity models to focus on specific areas of the design space, while low-fidelity models explore the entire space. Machine learning technologies, such as artificial neural networks and nonlinear autoregressive Gaussian processes, fill information gaps between different fidelity models, enhancing model accuracy. The multi-fidelity probabilistic optimisation framework is demonstrated through the reliability-based and robust design problems of aircraft composite structures under a thermo-mechanical environment, showing acceptable accuracy and reductions in computational time.

This unique volume presents the state of the art in the field of multiscale modeling in solid mechanics, with particular emphasis on computational approaches. For the first time, contributions from both leading experts in the field and younger promising researchers are combined to give a comprehensive description of the recently proposed techniques and the engineering problems tackled using these techniques.The book begins with a detailed introduction to the theories on which different multiscale approaches are based, with regards to linear Homogenisation as well as various nonlinear approaches. It then presents advanced applications of multiscale approaches applied to nonlinear mechanical problems. Finally, the novel topic of materials with self-similar structure is discussed.