http://hdl.handle.net/10453/148702 2026-07-23T17:15:27Z 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 http://hdl.handle.net/10453/195525 Title: Utilization of AC impedance spectroscopy (ACIS) for non-destructive damage evaluation of engineered cementitious composites (ECC) after exposure to high temperatures Authors: Ding, B; Xi, X; Han, J; Pan, J; Sui, X; Cai, J Abstract: Engineered cementitious composites (ECC) exhibit excellent tensile ductility and high-temperature resistance, making them ideal for use as fireproof coatings. Despite maintaining their external appearance after high-temperature exposure, ECC may experience significant internal microstructural and mechanical degradation, highlighting the need for non-destructive methods to assess post-fire safety. This study investigates the use of AC impedance spectroscopy (ACIS) for non-destructive damage evaluation of ECC after exposure to high temperatures. The mechanical properties of ECC were first examined after thermal exposure (20°C-600°C). AC impedance measurements (100Hz-5 MHz) were then conducted, utilizing an equivalent circuit model (ECM) for parametric analysis of conductive paths. Thermogravimetric analysis (TG) and X-ray computed tomography (X-CT) were employed to track thermal reactions and extract 3D pore structures for micro-level interpretation. The results confirmed the effectiveness of ACIS in characterizing ECC's damage after exposure to high temperatures, with frequency-dependent impedance changes serving as the key indicators. The ECM [R(C(RC))(RW)] incorporated electrical elements such as interfacial capacitance, charge-transfer impedance, and Warburg impedance, facilitating detailed interpretation of fiber melting and ion migration behaviors. The fitting errors for impedance modulus and phase angle were controlled within 4.93 % and 1.21°, respectively. Above 400°C, ionic migration ceased, and the fiber network transformed into interconnected pore structures, resulting in a marked increase in impedance and deterioration of both compressive strength and tensile properties. These findings highlight the high sensitivity and potential of ACIS for non-destructive applications, offering new insights into ECC's thermal decomposition mechanisms. 2025-04-04T00:00:00Z http://hdl.handle.net/10453/195524 Title: Study on the effect of silica fume dosage on the mechanical properties and chloride ion penetration resistance of ultra-high ductile cementitious composites (UHDCC) Authors: Sui, X; Yang, J; Huang, Y; Lu, C; Wang, Q; Zhuang, K; Xu, Y; Zhou, Y; Cai, J Abstract: The development of building materials that balance toughness and durability is critical for advancing infrastructure resilience. This study investigates the effects of silica fume (SF) admixture on the mechanical properties and chloride ion penetration resistance of ultra-high-ductility cementitious composites (UHDCC). UHDCC specimens with varying SF contents were prepared and subjected to mechanical property tests, chloride ion penetration resistance tests, and micro-morphological analysis to elucidate performance enhancements and underlying mechanisms. The results indicate that the incorporation of 10 % SF significantly improves the mechanical properties. Compared to the specimens without SF, the peak tensile stress and the corresponding strain increased by 332.64 % and 145.63 %, respectively. Furthermore, the non-stationary chloride migration coefficient was reduced to 1.20 × 10⁻¹² m²/s, which is 66.7 % of that of specimens without SF. These findings underscore the effectiveness of SF in enhancing UHDCC's structural and durability properties, providing valuable insights for advanced material design in infrastructure applications. 2025-08-01T00:00:00Z