http://hdl.handle.net/10453/148702 2026-10-15T05:28:23Z http://hdl.handle.net/10453/197114 Title: Frequency Spectrum and Energy Analysis of Stress Waves Vertically Incident on a Single Joint under Dynamic Loading Authors: Wu, B; Sun, D; Yang, L; Wang, J; Yao, W Abstract: The presence of joints in rock masses significantly compromises their mechanical integrity and alters stress wave propagation, critically impacting geotechnical safety. Quantifying how joint roughness governs stress-wave evolution is therefore critical for blast design, seismic hazard assessment, and underground excavation. This study investigates the influence of joint morphology on dynamic wave behavior using marble, granite, and sandstone specimens with realistic joints. The experimental data were analyzed in the frequency domain using the fast Fourier transform. The analysis revealed that while the shaping technique primarily controlled the time-domain characteristics (e.g., pulse width) of the initial stress wave, the subsequent energy conversion of the shock signal was predominantly altered by joint roughness. Furthermore, the extent of this alteration was found to be correlated with both the rock type and the pulse width of the incident wave. The energy conversion of the marble specimens is less sensitive to the incident pulse width than that of granite and sandstone. The incident wave pulse width also significantly affects the joint stiffness and closure volume. The joint stiffness is minimized and the closure volume is maximized when the pulse width is 360 μs. By defining the frequency transmission coefficient, it is found that all three specimens exhibit a severe attenuation effect for both frequency intervals, which is independent of the incident pulse width and the joint roughness.HighlightsGranite, marble, and sandstone specimens were prepared that reproduced realistic joint morphology characteristics.Dynamic compression tests were performed on three specimens at various incident pulse widths using the SHPB system.The fast Fourier transform technique was used to obtain spectrograms and the frequency transmission coefficient was defined.The energy conversion, joint stiffness and maximum closure were revealed in relation to the incident signal pulse width.The attenuation of each frequency component of the incident signal after penetrating the joint is analyzed as affected by JRC and the incident pulse width http://hdl.handle.net/10453/196123 Title: Aprendizado de regras de substituição para normatização de textos históricos Authors: Hirohashi, A Abstract: As ferramentas de lingüística computacional atuais geralmente são baseadas num léxico que contém apenas palavras normatizadas, ou seja, dentro da norma ortográfica vigente. No entanto, textos históricos... 2004-10-01T00:00:00Z http://hdl.handle.net/10453/195654 Title: PERMUTATION-INVARIANT PHYSICS-INFORMED NEURAL NETWORK FOR REGION-TO-REGION SOUND FIELD RECONSTRUCTION Authors: Chen, X; Zhao, S; Ma, F; Cheng, E; Burnett, IS Editors: Han, JH; Park, YH Abstract: Most existing sound field reconstruction methods target point-to-region reconstruction, interpolating the Acoustic Transfer Functions (ATFs) between a fixed-position sound source and a receiver region. The applicability of these methods is limited because real-world ATFs tend to varying continuously with respect to the positions of sound sources and receiver regions. This paper presents a permutation-invariant physics-informed neural network for region-to-region sound field reconstruction, which aims to interpolate the ATFs across continuously varying sound sources and measurement regions. The proposed method employs a deep set architecture to process the receiver and sound source positions as an unordered set, preserving acoustic reciprocity. Furthermore, it incorporates the Helmholtz equation as a physical constraint to guide network training, ensuring physically consistent predictions. Experiments on real-world datasets demonstrate that with limited ATFs, the proposed method achieves more accurate reconstructions than the kernel-based method. 2025-01-01T00:00:00Z http://hdl.handle.net/10453/195526 Title: Preparation of self-sensing engineered cementitious composites (ECC) sensor and its sensing performances in concrete column Authors: Han, J; Chen, P; Cai, J; Lai, Z; Pan, J; Song, Z; Li, Z Abstract: Self-sensing cementitious composites offer a promising solution for real-time and accurate structural integrity assessment in structural health monitoring. In this study, parameters of the self-sensing engineered cementitious composites (ECC) sensor were analyzed using ABAQUS/standard solver and a finite-element analysis model was established. Self-sensing ECC sensors were prepared via molding, hydration termination, wire connection and encapsulation. These sensors were then embedded within reinforced concrete columns to examine the column mechanical properties, including bearing capacity, crack development and failure patterns. To evaluate the sensing accuracy, sensor data was compared to strain gauge measurements. Results indicated that a 20 mm cubic sensor with a surface friction coefficient at least 0.6 was optimal and the sensor should be installed inside the matrix. It was observed that the sensor effectively monitored the deformation without affecting the structural integrity. In addition, high sensing accuracy was achieved under low load conditions, however, accuracy decreased as loading increased. 2025-03-15T00:00:00Z