Olavo Mecias Da Silva Junior

Small-bore pipes in compact machines carry fluid and transmit structural vibration between a source and its supporting structure. Consequently, this work introduces a vibrational objective function to optimize three-dimensional routing by minimizing active input power integrated over prescribed frequency bands. An ant colony algorithm constructs lattice paths that are fitted using B-spline smoothing with fixed endpoints and prescribed end directions. Routes are checked for developed length, minimum bend radius, containment, and obstacle avoidance before finite-element analysis. The smooth pipes are modelled using Timoshenko beams under coherent prescribed displacement at the source and a clamped terminal. This ensures that the algorithmically generated paths are physically valid and mesh-ready. An eigenfrequency-guided grid resolves narrow resonances, while modal superposition with residual flexibility reduces the evaluation cost. Examples in open and obstructed domains show lower input power and terminal reaction loads than deterministic baselines. On a representative case, the colony reached search objectives lower by factors of 2.4 to 6.0 than random construction with the same geometric filters and finite-element budgets. Five independent runs per case document the variation in final objectives. Direct solutions and mesh refinement quantify the approximation errors of the selected routes.

The four-parameter Burgers model is widely used in linear viscoelasticity, but evaluating its response to arbitrary loading histories typically relies on numerical time-stepping methods. While modern tools like Automatic Differentiation (AD) can extract exact gradients from these solvers for inverse identification, they inherently suffer from a fundamental truncationcomplexity trade-off. This work establishes a unified analytical framework for the Burgers model based on the method of Generalized Integrating Factors (GIF) that systematically resolves this computational bottleneck. By operating directly at the level of the constitutive differential operator, exact closed-form time-domain solutions are derived for both stressand strain-controlled protocols. A primary contribution lies in the derivation of exact analytical sensitivity kernels that recycle the exponential roots of the forward solution. To accommodate experimental protocols, a spline-parameterized formulation is introduced, enabling the direct processing of discrete data. Comparative analyses demonstrate that the proposed discretization-free Jacobians strictly avoid truncation errors while operating at a highly efficient O(N·K) complexity, outperforming traditional finite-difference and numerical AD approaches. Inverse identification results confirm that the proposed framework enables a single spline-interpolated transient test to successfully resolve all four material parameters simultaneously, offering a robust, machine-precision alternative to extensive frequency sweeps.

The four-parameter Burgers model is widely used in linear viscoelasticity, but evaluating its response to arbitrary loading histories typically relies on numerical time-stepping methods. While modern tools like Automatic Differentiation (AD) can extract exact gradients from these solvers for inverse identification, they inherently suffer from a fundamental truncationcomplexity trade-off. This work establishes a unified analytical framework for the Burgers model based on the method of Generalized Integrating Factors (GIF) that systematically resolves this computational bottleneck. By operating directly at the level of the constitutive differential operator, exact closed-form time-domain solutions are derived for both stressand strain-controlled protocols. A primary contribution lies in the derivation of exact analytical sensitivity kernels that recycle the exponential roots of the forward solution. To accommodate experimental protocols, a spline-parameterized formulation is introduced, enabling the direct processing of discrete data. Comparative analyses demonstrate that the proposed discretization-free Jacobians strictly avoid truncation errors while operating at a highly efficient O(N·K) complexity, outperforming traditional finite-difference and numerical AD approaches. Inverse identification results confirm that the proposed framework enables a single spline-interpolated transient test to successfully resolve all four material parameters simultaneously, offering a robust, machine-precision alternative to extensive frequency sweeps.

Este texto reúne quatro resenhas de livros essenciais para profissionais e estudantes interessados em acústica, vibrações e áudio. As obras selecionadas abrangem desde princípios fundamentais até aplicações avançadas, oferecendo uma visão abrangente sobre temas como processamento de sinais, arranjos de microfones, acústica arquitetônica e estudos práticos. A primeira obra, Concert Halls and Opera Houses: Music, Acoustics and Architecture, de Leo Beranek, explora a relação entre a arte musical e o projeto de espaços de espetáculo, evidenciando como a acústica influencia diretamente a experiência do ouvinte. Em seguida, Acoustic Array Systems: Theory, Implementation, and Application, de Mingsian R. Bai, Jeong-Guon Ih e Jacob Benesty, aprofunda-se em tecnologias de arranjos de microfones, analisando teorias de conformação de feixes e suas aplicações práticas. A terceira referência, Architectural Acoustics, de Marshall Long, destaca os princípios de planejamento e tratamento acústico em salas, permitindo maior controle sobre ruídos e reverberações em diferentes ambientes. Por fim, Acoustics – A Textbook for Engineers and Physicists (Vols. I & II), de Jerry H. Ginsberg, apresenta um compêndio completo sobre acústica e vibrações, unindo teoria, modelagem computacional e experimentos. As resenhas, concisas e objetivas, fornecem informações iniciais sobre as contribuições de cada autor, estimulando a leitura integral das obras para uma formação sólida e atualizada na área de acústica.

This text brings together four essential book reviews for professionals and students interested in acoustics, vibrations, and audio. The selected works range from fundamental principles to advanced applications, offering a comprehensive overview of subjects such as signal processing, microphone arrays, architectural acoustics, and practical studies. The first work, Concert Halls and Opera Houses: Music, Acoustics and Architecture by Leo Beranek, explores the relationship between musical art and the design of performance venues, highlighting how acoustics directly affects the listener’s experience. Next, Acoustic Array Systems: Theory, Implementation, and Application by Mingsian R. Bai, Jeong-Guon Ih, and Jacob Benesty, delves into microphone array technologies, examining beamforming theories and their practical applications. The third reference, Architectural Acoustics by Marshall Long, focuses on the principles of room planning and acoustic treatment, allowing greater control over noise and reverberations in different environments. Finally, Acoustics – A Textbook for Engineers and Physicists (Vols. I & II) by Jerry H. Ginsberg presents a comprehensive compendium on acoustics and vibrations, combining theory, computational modeling, and experiments. These concise and objective reviews provide initial insights into each author’s contributions, encouraging the complete reading of the works for a solid and up-to-date education in the field of acoustics.