Structural health monitoring of high-speed railway tracks using diffuse ultrasonic wave-based condition contrast: theory and validation

Kai Wang,Wuxiong Cao,Zhongqing Su,Pengxiang Wang,Xiongjie Zhang,Lijun Chen,Ruiqi Guan,Ye Lu 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.2

Despite proven effectiveness and accuracy in laboratories, the existing damage assessment based on guided ultrasonic waves (GUWs) or acoustic emission (AE) confronts challenges when extended to real-world structural health monitoring (SHM) for railway tracks. Central to the concerns are the extremely complex signal appearance due to highly dispersive and multimodal wave features, restriction on transducer installations, and severe contaminations of ambient noise. It remains a critical yet unsolved problem along with recent attempts to implement SHM in bourgeoning high-speed railway (HSR). By leveraging authors' continued endeavours, an SHM framework, based on actively generated diffuse ultrasonic waves (DUWs) and a benchmark-free condition contrast algorithm, has been developed and deployed via an all-in-one SHM system. Miniaturized lead zirconate titanate (PZT) wafers are utilized to generate and acquire DUWs in long-range railway tracks. Fatigue cracks in the tracks show unique contact behaviours under different conditions of external loads and further disturb DUW propagation. By contrast DUW propagation traits, fatigue cracks in railway tracks can be characterised quantitatively and the holistic health status of the tracks can be evaluated in a real-time manner. Compared with GUW- or AE-based methods, the DUW-driven inspection philosophy exhibits immunity to ambient noise and measurement uncertainty, less dependence on baseline signals, use of significantly reduced number of transducers, and high robustness in atrocious engineering conditions. Conformance tests are performed on HSR tracks, in which the evolution of fatigue damage is monitored continuously and quantitatively, demonstrating effectiveness, adaptability, reliability and robustness of DUW-driven SHM towards HSR applications.

Influence of Hemp Fiber Softening Treatment & Blend Ratio on Quality Characteristics of Hemp-Based Ternary Blended YARNS

Chuanhe Li,Ruiqi Shao,Chunhong Wang,Guangwei Fu,Bingjie Yang 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

Quality characteristics of blended yarns, which play an important role in textile quality, are continually assessed by softness, breaking strength, breaking elongation, hairiness, irregularity, etc. In this study, hemp was softened and blended with other cellulose fibers with better softness to produce yarns. The softness of hemp is obviously lower than that of the other two fibers. With the increase of hemp fiber percentage content, the yarn properties deteriorated. Therefore, the softening treatment of hemp fiber is very necessary. Moreover, the blending hemp, cotton, and viscose in the yarn structure provided synergies, improving the weak properties of ternary fibers. Results show that softening treatment and lower percentage content of the hemp fiber will result in better yarn quality, which is consistent with the derivation result of the bending theoretical model. When the percentage content of treated hemp is 40 wt%, the overall performance of blended yarn is the best. Compared with the untreated hemp-based ternary blended yarns, the hairiness of blended yarn is significantly less (3.65 ends/m, compared to 12.23 ends/m), and the irregularity of yarn is lower (27.33% and 27.70%, respectively), yarn quality improved considerably. In addition, the resulting hemp yarn showed antibacterial activity against Escherichia coli and Staphylococcus aureus.

Settlement behaviours and control measures of twin-tube curved buildings-crossing shield tunnel

Jianwei Jia,Ruiqi Gao,Defeng Wang,Jianjun Li,Ziwen Song,Jinghui Tan 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.5

Settlement control techniques are critical for the safety of shield tunnel constructions, especially for facing complex situations. In this study, the shield tunnel structure from Huaita east road station to Heping Road station in Xuzhou metro No.3 line (China) is taken as engineering background, which has various complex problems of the upper-soft and lower-hard composite stratum conditions, twin curve shield tunnels, and underpass the foundation of the piled raft. The deformation characteristics of shield tunnelling passing through buildings are explored. Subsequently, comprehensive research methods of numerical simulation and field measurement are adopted to analyzing the effectiveness of settlement control by using the top grouting technique. The results show that the settlement of the buildings has obvious spatial characteristics, and the hysteresis effect can be obviously observed in soil deformation caused by shield construction. Meanwhile, the two shield constructions can cause repeated disturbances, reducing the soil deformation's hysteresis effect. Moreover, the shield tunnel's differential settlement is too large when a single line passes through, and the shield construction of the outer curve can cause more significant disturbance in the tunnel than the inside curve. Notably, the proposed process control parameters and secondary topgrouting method can effectively control the deformation of the shield tunnel, especially for the long-term deformation.

Transition metal modified manganese-based catalysts for soot oxidation promoted by noncompetitive adsorption of oxygen: Experiments and DFT calculations

Congcong Li,Ruiqi Li,Yuhang Wang,Runhan Niu,Qilong Guo,Changsen Zhang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

A series of manganese-based oxide catalysts were synthesized by the hydrothermal method. By adjustingthe doping amounts of W and Cu in the system to study the catalytic performance of transition metaldopedmanganese oxides on soot combustion. They were deeply studied through various characterizationsand theoretical calculations. The results show that Wand Cu doping modifications can significantlyimprove the activity of manganese-based oxides in soot oxidation. W-Cu0.1/MnOx prepared by comodificationofWand Cu at 395 C can convert 90% of soot into CO2. The multiple characterization resultsshow that by adjusting the doping amount of copper and tungsten, the nano-flower-like morphology canbe obtained and the crystal plane can be reconstructed, which is helpful to increase the specific surfacearea, Mn3+ content, and oxygen vacancy content. The theoretical calculation results show that the oxygenvacancy on the surface of the catalyst shows the ability to activate O2 and H2O, and they show noncompetitiveadsorption. In addition, W-Cu0.1/MnOx has a good application prospect in the catalytic oxidationof soot because of its excellent catalytic stability. This work provides a reference for the designand preparation of non-noble metal-based catalysts for the elimination of soot particles from dieselengine exhaust.

Adaptive Synchronization of Chaotic Systems with known Response System Parameters

Cheng Gan,Yuan Cheng,Ruiqi Wang,Junwei Lei 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.5

A kind of adaptive synchronous control method was proposed to solve a special synchronization problem between two chaotic systems, where the response system is totally known without uncertainty but the driven system contains both unknown parameters and uncertain nonlinear functions. An update law of estimation of unknown parameters of driven system by constructing a proper Lyapunov energy function and the stability of the whole system was guaranteed by Lyapunov stability theorem. What is worthy pointing out is that the chaotic systems are not required to satisfy the Lipscitz condition. At last, detailed numerical situation was done to show the rightness and effectiveness of the proposed method.

Dynamic numerical analysis of single-support modular bridge expansion joints

Wancheng Yuan,Xinzhe Yuan,Ruiqi Li,Jian’guo Wang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.1

Severe fatigue and noise problems of modular bridge expansion joints (MBEJs) are often induced by vehicle loads. However, the dynamic characteristics of single-support MBEJs have yet to be further investigated. To better understand the vibration mechanism of single-support MBEJs under vehicle loads, a 3D finite element model of single-support MBEJ with five center beams is built. Successive vehicle loads are given out and the vertical dynamic responses of each center beams are analyzed under the successive loads. Dynamic amplification factors (DAFs) are also calculated along with increasing vehicle velocities from 20 km/h to 120 km/h with an interval 20 km/h. The research reveals the vibration mechanism of the single-support MBEJs considering coupled center beam resonance, which shows that dynamic responses of a given center beam will be influenced by the neighboring center beams due to their rebound after the vehicle wheels depart. Maximal DAF 1.5 appears at 120 km/h on the second center beam. The research results can be utilized for reference in the design, operation and maintenance of singlesupport MBEJs.

Parameters Adaptive Control of Uncertain Chaotic Systems

Shujun Liang,Haiyan Liu,Ruiqi Wang,Junwei Lei 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.12

The bound of static uncertain function of chaotic system is required to be known by using adaptive method in many past research papers. Or many papers only considered the situation of the systems with simple uncertain nonlinear functions. In this paper, a kind of generalized chaotic systems are taken as an example, and an adaptive control algorithm with static uncertain nonlinear functions is proposed to control chaotic systems. The requirements for nonlinear function of system is relaxed by using the proposed algorithm. It only requires that the bound of the nonlinear functions in the system model exists and some part of it is known. At last, detailed numerical simulation is done to testify the rightness of the proposed method. It shows that the stabilization and tracking of chaotic system with static uncertain functions can be realized with a quick response by using the proposed algorithm.

Synchronization of Uncertain Chaotic System with Unknown Response System Parameters

Zhanlei Shang,Wenjun Song,Ruiqi Wang,Junwei Lei 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.4

Synchronization of chaotic system is meaningful and widely used in secure communication. A kind of robust adaptive synchronization method was proposed to solve a special chaotic synchronization problem that both response system and driven system have unknown parameters and uncertain nonlinear functions. And the difficulty is also caused by the different structures between master chaotic system and slave chaotic system. A kind of update law of estimation of unknown parameters were designed by choose a proper Lyapunov energy function. And the stability of the whole system is guaranteed by Lyapunov stability theorem. At last, detailed numerical simulation was done to show the rightness of the proposed method.

Functional analysis of prv-miR-LLT11a encoded by pseudorabies virus

Huimin Liu,Li Yang,Zhibin Shi,Ruiqi Lv,Xia Yang,Chuanqing Wang,Lu Chen,Hongtao Chang 대한수의학회 2019 Journal of Veterinary Science Vol.20 No.6

Viral-encoded microRNAs (miRNAs) play have vital roles in the regulations of virus replications and host immune responses. The results of previous studies have indicated that miRNA clusters are involved in the replication and virulence of the pseudorabies virus (PRV), which may potentially lead to the immune escape or facilitation of PRV replications. This study's previous research revealed that the prv-mirmiR-LLT11a was differentially expressed during PRV infections. The present study's results have demonstrated that the prv-miR-LLT11a could significantly inhibit PRV replications. It was further determined that SLA-1 was the target gene of the prv-miR-LLT11a, and simultaneously, thate overexpression of prv-miR-LLT11a could down-regulate the mRNA and protein levels of SLA-1 in a dose-independent manner. Furthermore, the present study also found observed that the prv-miR-LLT11a canhad also down-regulated the TAP1 expressions. Our findings provide a better understanding of the molecular mechanism involved in on the effects of prv-miR-LLT11a on SLA-1 and TAP1, as well as and its involvement in a potential immune system evasion of PRV.

Research on Two Kinds of Adaptive Synchronization Method for Uncertain Fourth Order Chaotic Systems based on Sigmoid Function and Soft Function Method

Zhanlei Shang,Jing Cheng,Junwei Lei,Ruiqi Wang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.6

Synchronization of chaotic systems can be used in the secure communication so it greatly attracted interests of many researchers. The bounded characteristics of chaotic system was used and an uniformed adaptive law was designed to solve system uncertainties which make the whole design very simple. And two kinds of functions was used to take place of traditional sign function, then the chattering problem was greatly improved. A Lyapunov function was chosen to guarantee the stability of the whole design. At last, detailed simulation was done to show the rightness and effectiveness of the proposed method.