Traditional transmission line fault diagnosis approaches ignore local structure feature information during feature extraction and cannot concentrate more attention on fault samples, which are ...difficult to diagnose. To figure out these issues, an enhanced feature extraction-based attention temporal convolutional network (EATCN) is developed to diagnose transmission line faults. The proposed EATCN suggests a new comprehensive feature-preserving (CFP) technique to maintain the global and local structure features of original process data during dimension reduction, where the local structure-preserving technique is incorporated into the principal component analysis model. Furthermore, to diagnose transmission line faults more effectively, a CFP-based attention TCN scheme is constructed to classify the global and local structure features of a fault snapshot dataset. To be specific, to cope with the gradient disappearance problem and improve learning capability, a skip connection attention (SCA) network is developed by incorporating a skip connection structure and two fully connected layers into the existing attention mechanism. By combining the developed SCA network with the conventional TCN’s residual blocks, an EATCN-based diagnosis model is then constructed to dynamically pay attention to various imported global and local structure features. Detailed experiments on the datasets of the simulated power system are performed to test the effectiveness of the developed EATCN-based fault diagnosis scheme.
The flexural behaviour is investigated in this paper for engineered cementitious composite (ECC)-reinforced concrete (RC) composite beams. The thickness and shape of the ECC layer are the variables ...studied. ECC has proved to be one of the ideal construction materials for improving the flexural capacity of reinforced conventional concrete beams. When the composite beam specimens reached the load-bearing limit state, only dense micro-cracks appeared in the ECC layer in the tensile zone, and no local fracture was observed in the test, reflecting the high ductility of ECC. The load values for all phases of the ECC-RC composite beams are higher than those of the RC beams, suggesting that the composite beams have better ductility and energy absorption capacity. In addition, the ability of the U-shaped ECC layer composite beam to limit crack development and the synergistic effect with the reinforcement is superior compared to the other tested beams. Finally, considering the strain-hardening characteristics of ECC, based on the force equilibrium conditions, the formulae are derived for the flexural capacity of ECC-RC composite beams.
At present, there is still a lack of relevant theoretical guidance on the deployment of roadside RSU on expressways. In the face of the coexistence of V2V and V2I communication in the future, the ...deployment adjustment after the penetration of intelligent vehicles is not considered. Therefore, this paper proposes a roadside RSU deployment income model in consideration of the influence of V2V and V2I communication. Based on the optimal income of roadside RSU nodes, it achieves the optimization of the RSU deployment range and determines the optimal deployment spacing through the forwarding and relaying role of V2V communication so as to achieve cost savings. In terms of RSU coverage of positive income, it considers the impact of intelligent vehicles and reconstructs the traditional information flow–traffic flow coupling theory to innovatively realize the modeling of income within the information life cycle. In terms of the information transmission deficit, the WSN node energy loss model is reconstructed with permeability. Also, in terms of the construction and maintenance costs, the cost models are constructed for different cluster lengths. In order to provide a basis for expressway sensor network deployment, MATLAB software (version R2016B) is used to analyze the three-dimensional relationship between expressway traffic density, intelligent vehicle permeability, and roadside RSU deployment spacing as well as to determine the optimal roadside RSU deployment spacing with the income model. Finally, the model reliability is validated by the Warshell algorithm and the Kmeans clustering algorithm.
The purpose of the study is to clarify the curing effect of raw material composition on waterborne epoxy resin, thereby further improving working performance of waterborne epoxy resin. Based on the ...preferred variety of epoxy resins and curing agents, different types of waterborne epoxy resins were prepared. The effects of different raw material compositions on the physical properties of waterborne epoxy resin were studied systematically. The reasonable material composition and proportion were determined. The influence of physical properties of waterborne epoxy resin on its adhesion properties was evaluated. The results show that raw material composition has a large impact on the working performance of waterborne epoxy resin. The combination of E-44 waterborne epoxy resin and alicyclic amine has the best comprehensive property. And it is 3.65-36.22% higher than other combinations. The adhesive property index of waterborne epoxy resin has a high correlation with the mechanical property index, and they are in direct proportion.
•The TDI-polyether polyurethane prepolymer modified epoxy resin was prepared.•The optimal amount of TDI-polyether polyurethane prepolymer and preferred curing agents were determined.•The durability ...of the TDI-PUP-M-ER bonding material was systematically evaluated.
The performance of the bonding materials of colorful anti-slip pavements is a critical factor influencing their service life. To obtain a bonding material with good flexibility and durability, TDI-polyether polyurethane prepolymer modified epoxy resin (TDI-PUP-M-ER) was prepared. The basic performances of TDI-PUP-M-ER were studied. The optimal amount of TDI-polyether polyurethane prepolymer (TDI-PUP) and preferred curing agents for the TDI-PUP-M-ER were determined. Furthermore, the durability of the TDI-PUP-M-ER bonding material was systematically evaluated. The results showed that the flexibility and mechanical strength of the epoxy resin are considerably improved by adding TDI-PUP. When the content of TDI-PUP in epoxy resin was 10%, compared with the pure epoxy resin, the tensile strength of TDI-PUP-M-ER was improved by 52.8%, its elongation at break by 112%, its bending strength by 21.6%, and its bending deformation by 61.1%. After corrosion condition, the final mass loss rate of the resin was only 0.69–1.08 mg/g, showing that the TDI-PUP-M-ER bonding material exhibits good durability.
Polyethylene (PE) fiber is widely used in high strength engineered cementitious composites (ECC) due to its exceptional mechanical properties. However, the strong hydrophobicity of PE fibers hinders ...the bonding between fibers and matrix. To enhance the interfacial bond and fully utilize the reinforcing effect of PE fiber, this study employed polyvinylpyrrolidone (PVP) to modify the surface of PE fiber. The improvement effect of various PVP solution concentrations on ECC behavior was investigated. The microscopic characterization tests revealed that the surface of PE fibers was effectively coated by PVP, and the hydrophilicity of PE fibers was significantly improved after modification. Uniaxial tensile tests demonstrated that after PVP modification, the tensile strength and ultimate tensile strain of ECC increased by 20.7–27.2% and 87.3–109.3%, respectively. Furthermore, the ECC with modified PE fibers exhibited a decrease of 10–20% in the average crack width, coupled with a nearly twofold increase in the number of cracks, compared to the pristine ECC specimens. At microscale, the single fiber pull-out tests demonstrated that the interfacial frictional bond between fiber and matrix was effectively enhanced after PVP modification. The proposed method of modifying PE fibers surface with PVP offered a simple and environmentally friendly approach to enhance the strain hardening behavior of ECC, which provided valuable insights for optimizing the design of high strength ECC.
•The PE fiber was modified by using polyvinylpyrrolidone (PVP) solutions.•The tensile properties of high strength ECC were improved upon fiber modifications.•The fiber/matrix interfacial bond was enhanced after PVP modification to PE fiber.
The static mechanical properties of grouped-stud shear connectors in steel–ultra-high-performance concrete (UHPC) composite beams are rarely investigated. In this study, the static mechanical ...properties of grouped-stud shear connectors in steel–UHPC composite beams are investigated via experiments and numerical simulations. Seven sets (14 specimens) of push-out tests are conducted by varying the parameters, including the concrete type, stud diameter, stud vertical spacing, and number of stud rows. The test results show that the shear bearing capacity of grouped-stud shear connectors increases by 27.5% as the stud diameter increases from 19 to 22 mm, by 13.2% compared with that of grouped-stud shear connectors in steel–UHPC and steel–normal concrete (NC), and by 5.8% when the stud vertical spacing increases from 125 mm (5.68d) to 200 mm (9.09d). However, the shear bearing capacity of the grouped-stud shear connectors remain almost unchanged when the number of stud rows is changed from two to four. The effects of stud diameter, stud tensile strength, stud vertical spacing, stud length, the cover thickness of the stud head, and stud transverse spacing on the shear bearing capacity of the grouped-stud shear connectors are investigated via numerical simulations. The results show that the stud diameter, stud tensile strength, and stud vertical spacing significantly affect the shear bearing capacity of the grouped-stud shear connectors, whereas the stud length, the cover thickness of the stud head, and stud transverse spacing exert almost no effect. Based on experimental and numerical analyses, an equation for predicting the shear bearing capacity of grouped-stud shear connectors in steel–UHPC is proposed and validated based on experimental and numerical results.
•The static mechanical properties of grouped-stud shear connectors in steel–UHPC composite beams are investigated.•A nonlinear finite element model was developed and verified using tests results.•The Shear carrying capacity of the grouped-stud shear connectors in steel–UHPC is evaluated using current codes.•A formula for predicting the shear bearing capacity of grouped-stud shear connectors in steel–UHPC is proposed and validated based on experimental and numerical results.
Tracking road users with high resolution is important for connected vehicles. Due to the complicated environments, tracking objects with a single sensor could not meet the requirements of ...high-resolution trajectories due to occlusions. How to acquire accurate and complete trajectories based on multisource data is a major challenge for researchers and engineers. This article developed a novel tracking method based on the fusion of roadside light detection and ranging (LiDAR) and camera. According to the relationship between the number of points and distance, the adaptive weight coefficient related to 3-D trajectory information was determined. The performance of the proposed method was evaluated at five selected sites. The proposed tracking method had high performance in terms of speed calculation, tracking range, the rate of object loss, and the repairing rate of disconnected trajectories. The proposed method can benefit many transportation areas, such as traffic volume counting, vehicle speed tracking, and traffic safety analysis.
Recently, the traditional transmission line fault diagnosis approaches cannot handle the variables’ dynamic coupling properties, and they also ignore the local structure feature information during ...the feature extraction. To figure out these issues, a novel enhanced feature extraction based convolutional LSTM (ECLSTM) approach is developed to diagnose the transmission line fault in this paper. Our work has three main contributions: (1) To tackle the dynamic coupling characteristics of the process variables, the statistics analysis (SA) method is first employed to calculate different statistical features of the transmission line’s original data, where the original datasets are transformed into the subsequently used statistics datasets; (2) The statistics comprehensive feature preserving (SCFP) is then proposed to maintain both the global and local structure features of the constructed statistics datasets, where the locality structure preserving technique is incorporated into the principal component analysis (PCA) model to extract the features from the statistics datasets; (3) To effectively diagnose the transmission line’s fault, the SCFP based convolutional LSTM fault diagnosis scheme is constructed to classify the global and local statistical structure features of fault snapshot dataset, because of its ability to exploit the temporal dependencies and spatial correlations of the extracted statistical features. Detailed experiments and comparisons on the datasets of the simulated power system are performed to prove the excellent performance of the ECLSTM based fault diagnosis scheme.
With the increasing number of Connected and Autonomous Vehicles (CAVs), the heterogeneous traffic flow on highways now consists of a mix of CAVs and Non-networked Autonomous Vehicles (NAVs). The ...current deployment of Roadside Units (RSUs) on highways is mostly based on uniform or hotspot locations. However, when the permeability of CAVs on the road varies, the communication network may face challenges such as excessive energy consumption due to closely spaced RSU deployments at high CAV permeability or communication interruptions due to widely spaced RSU deployments at low CAV permeability. To address this issue, this paper proposes an improved D-LEACH clustering algorithm based on vehicle clustering; analyzes the impact of RSU and vehicle communication radius, mixed traffic density, and different CAV permeabilities in the heterogeneous traffic flow on the RSU deployment interval; and calculates the rational and effective RSU deployment interval schemes under different CAV permeabilities on highways in the heterogeneous traffic flow. When the heterogeneous traffic flow density is stable and CAV continues to penetrate, the RSU communication radius and deployment interval can be adjusted to ensure that the network connectivity is maintained at a high level. When the RSU and vehicle communication radius are stable, the mixed traffic density is 0.05, and the CAV permeability is 0.2, the RSU deployment interval can be set to 1235 m; when the mixed traffic density is 0.08 and the CAV penetration rate is 0.7, the RSU deployment interval can be set to 1669 m to ensure that the network connectivity is maintained at a high level.
