This paper investigates energy dissipation and operating time of a vibro-impact capsule robot powered by a compact LIR1040 lithium battery under pulse-width modulation (PWM) excitation. An improved mathematical model incorporating coil inductance and a nonlinear excitation force is developed and validated against experiments. Numerical simulations and laboratory tests quantify losses from viscous damping, Coulomb friction, and impact events, and show their dependence on excitation frequency and duty cycle. Analysis of hysteresis loops of impact force versus relative displacement and relative velocity clarifies how collision dynamics convert mechanical energy into irreversible loss. Higher frequencies generally favor forward locomotion with reduced impact losses, while lower frequencies produce larger instantaneous displacements and faster energy dissipation. Comparison of theoretical operating time based on battery capacity with operating time accounting for voltage decay reveals that voltage drop substantially shortens effective operation. Practical PWM tuning guidelines are provided to balance locomotion efficiency and battery endurance for biomedical and industrial applications.
This study presents a BIM-integrated automated shape quality control framework for precast concrete elements, designed to enhance accuracy, efficiency, and traceability in industrial inspection processes. The proposed five-stage workflow combines 3D laser scanning, point-cloud preprocessing, two-stage registration (edge-point alignment and Iterative Closest Point refinement), deviation analysis, and BIM-linked reporting. Using a dataset of 820 precast arch segments, the method achieved a mean registration RMSE of 1.58 mm, representing a 43% improvement in dimensional accuracy compared to manual inspection. The fully automated process reduced inspection time by 40% and achieved 100% defect-detection sensitivity while maintaining consistency under variable environmental conditions. Color-coded deviation heatmaps and digital audit reports were automatically linked to BIM object identifiers, ensuring full compliance with ISO 19650 and ISO 9001 standards for information and quality management. The results demonstrate that the proposed method provides a practical foundation for digital transformation in precast production and aligns with the objectives of Smart Structural Systems by establishing a data-driven, ISO-compliant, and scalable framework for automated geometric quality assurance.
With the increase of bridge service life, various loads, environmental corrosion and material aging may lead to the accumulation of structural damage, it is significant to identify structural damage to provide maintenance strategies and prevent collapse accidents. Abridge damage identification method based on fused multi-point deflection influence line area is proposed in this study. Initially, the variational mode decomposition (VIVID) technique is introduced to decompose the structural dynamic deflection under moving load, which will separate the dynamic fluctuation disturbance component from the structural low-frequency deflection response. In order to reduce the number of unknown variables to be solved and smooth the local fluctuations in the solution caused by noise, the B-spline basis functions are used to expand the influence line, which will transform the identification of influence line into solving the weight coefficients of base functions. Subsequently, the influence lines of the simply supported bridge before and after damage are derived, and a damage index based on the area difference of influence lines of fusing multi-point is proposed. Finally, a numerical simulating and experimental testing under various damage cases are studied to validate the feasibility of the proposed method. The dynamic fluctuation interference can effectively eliminate and the influence line can be accurately identified by proposed method. The fused damage index can effectively identify and localize structural damage under various damage cases, and the identification result is better and more stable than the damage index of single measurement point.
To improve the frequency sensitivity of a single tuned mass damper (TMD) and solve the complexity for multiple tuned mass dampers (MTMD) to determine the control mode and the effective number of TMDs, a new type of MTMD, namely rocking wall tuned mass dampers (RW-TMDs), is proposed in this paper based on the structural characteristics of rocking wall and the damping principle of TMD. To prove the effectiveness of RW-TMDs, theoretical analysis and numerical simulations were used to compare the damping effects of uncontrolled structures and controlled structures with TMD and RW-TMDs, respectively, under Gaussian white noise and different earthquake excitations. The results show that the RW-TMDs arranged along the height of the structure can effectively alleviate the frequency sensitivity of TMD, significantly reducing structural peak and root mean square value of acceleration and displacement. Besides, RW-TMDs with advantages of rocking wall structure can control inter-layer deformation mode and prevent the occurrence of layer collapse mechanism, efficiently. Furthermore, the RW-TMDs can mitigate structural damage degree by increasing the damping energy dissipation and reducing the plastic energy dissipation. Therefore, the RW-TMDs have a high potential in practical applications for vibration control of building.
To evaluate the load carrying capacity of a bridge, it is necessary to set up an appropriate analytical model for the bridge. According to the current guideline or manual, the load rating is calculated with the response correction factor obtained from the difference between the response measured through the field load test and the response by the analytical model. According to the criteria for evaluating the load capacity, for conservative evaluation, it is suggested to use the response correction factor at the location where the axle weight of the test vehicle is directly applied, and to select the location with the largest response correction factor. The purpose of this study is to propose and examine a method for estimating the load rating of PSC-I girder bridges by updating the model that minimizes the difference between the measured and analyzed responses with a real-coded genetic algorithm (RCGA). In addition, the reliability of the method for estimating the load rating through the available response correction factor was investigated. The results were compared with those of the genetic algorithm (GA) model updating method. In the study, a pseudo-static load test method was proposed and applied as a field load test for PSC-I girder bridges, and its advantages were analyzed.
