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Zhang, A. (author)Bio-mediated methods, such as microbially induced carbonate precipitation (MICP) and enzyme induced carbonate precipitation (EICP), have gained considerable attention as alternatives to invasive ground improvement techniques. MICP and EICP use biogeochemical processes to drive carbonate precipitation and bind soil grains, thereby improving the...doctoral thesis 2024
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Zhang, P. (author), He, C. (author), Shen, C. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)Wheel-rail high-frequency interaction is closely related to the formation of railway short-wave defects. Finite element (FE) method has been widely used to simulate wheel-rail dynamic systems, but its validity in modelling high-frequency interaction has not been fully demonstrated in three dimensions (3D). This work aims at comprehensively...journal article 2024
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He, C. (author), Yang, Z. (author), Zhang, P. (author), Li, S. (author), Naeimi, M. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)Polygonal wear is a type of damage commonly observed on the railway wheel tread. It induces wheel-rail impacts and consequent train/track components failure. This study presents a finite element (FE) thermomechanical wheel-rail contact model, which is able to cope with the three possible generation and development mechanisms of polygonal wear...journal article 2024
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Zhang, P. (author), Li, S. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)Short pitch corrugation has been a problem for railways worldwide over one century. In this paper, a parametric investigation of fastenings is conducted to understand the corrugation formation mechanism and gain insights into corrugation mitigation. A three-dimensional finite element vehicle–track dynamic interaction model is employed, which...journal article 2024
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Li, Shizhen (author), Liu, X. (author), Gao, Chenshan (author), Wang, S. (author), Li, Jun (author), Ye, Huaiyu (author), Zhang, Kouchi (author), Wu, Shaohui (author)The significance of wafer bonding is fundamental to the progression of electronic systems. Common fabrication techniques for Cu pillars play a crucial role in establishing resilient and efficient interconnects within semiconductor devices. It is imperative to explore the potential of nano-copper as an alternative material to overcome limitations...conference paper 2024
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Hu, D. (author), Wang, Chieh (author), Li, Z. (author), Gupta, N. (author), Poelma, René H. (author), Shi, Ziliang (author), Fan, J. (author), Zhang, Kouchi (author)Driven by the increasing demand for high-power systems, ceramic substrates have received more attention for handling higher power density. Warpage in active metal brazed (AMB) ceramic substrate becomes a critical issue as it can deteriorate the reliability performance. This study comprises three phases, including investigation of the cause of...conference paper 2024
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Qin, Guojin (author), Zhang, Zhenwei (author), Hou, Xiangqin (author), Lu, Hongfang (author), Huang, Y. (author), Wang, Yihuan (author)In this work, a 3D finite element (FE) based model was developed to assess the condition of an underground hydrogen transmission pipeline containing a corrosion defect under combined internal pressure and soil movement-induced axial compression. The use of mechanical properties of X100 pipeline steel under different hydrogen charging time...journal article 2023
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Zhang, Jujian (author)This thesis introduces the Discontinuity-Enriched Finite Element Method (DE-FEM) for the modeling of dynamic multiple crack growth problems including branching and merging, as an alternative to eXtended/Generalized Finite Element Method (X/GFEM). DE-FEM differs from X/GFEM by placing the enriched degrees of freedom (DOFs) directly along the...master thesis 2023
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Yang, Zhe (author), Liu, Zhou (author), Zhang, Qi (author), Chen, Zhe (author), de Jesus Chavez, Jose (author), Popov, M. (author)The traditional fault control strategy of converter-interfaced renewable energy sources (CIRESs) may bring about a lower sensitivity level or misoperation of fault component-based directional elements. To overcome this problem, a new control scheme is proposed to adjust sequence impedance angles of CIRESs by computing suitable current...journal article 2023
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Inamdar, A.S. (author), van Soestbergen, Michiel (author), Mavinkurve, Amar (author), van Driel, W.D. (author), Zhang, Kouchi (author)Moulding compounds used for encapsulating electronics typically occupy a large portion of package volume and are most exposed to the external environment. Under harsh conditions such as high temperature, humidity, and mechanical vibrations, constituent materials of electronic components degrade, resulting in a change in their thermal, mechanical...conference paper 2023
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Hu, D. (author), Qian, Cheng (author), Liu, X. (author), Du, L. (author), Sun, Zhongchao (author), Fan, X. (author), Zhang, Kouchi (author), Fan, J. (author)As a promising technology for high-power and high-temperature power electronics packaging, nanocopper (nanoCu) paste sintering has recently received increasing attention as a die-attachment. The high-temperature deformation of sintered nanoCu paste and its underlying mechanisms challenge the reliability of high-power electronics packaging. In...journal article 2023
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Yu, Haoyuan (author), Zhang, Hanwen (author), Wang, Yanbo (author), Qin, Z. (author), Chen, Zhe (author), Bauer, P. (author)This article investigates the stability of triple active bridge (TAB) converter with different types of loads. In this paper, port2 of TAB converter adopts voltage control to supply a constant power load (CPL), and port3 uses voltage control to supply a resistor or uses current control to supply a battery. Then, an extra element theorem-based ...conference paper 2023
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Zhang, H. (author), Berkhout, M. (author), Makinwa, K.A.A. (author), Fan, Q. (author)This article presents a digital-input class-D amplifier (CDA) achieving high dynamic range (DR) by employing a chopped capacitive feedback network and a capacitive digital-to-analog converter (DAC). Compared with conventional resistive-feedback CDAs driven by resistive or current-steering DACs, the proposed architecture eliminates the noise...journal article 2023
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Li, Jianguo (author), Wang, Bin (author), Wang, Di (author), Zhang, Pei (author), Vardon, P.J. (author)Aiming at modelling the mechanical behaviour of soil-rock mixtures accurately and efficiently, a coupled MPM-DEM formulation combining the material point method (MPM) and the discrete element method (DEM) is proposed. It is solved concurrently via the contact force linking the two individual methods. Specifically, the soil is modelled with...journal article 2023
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Xue, Li Hua (author), Xiao, Jun Hua (author), Zhang, De (author), Guo, Y. (author), Chen, Bing Wen (author)Particle shape plays an essential role in deformation characteristics of railway ballast bed. The numerical reconstruction of ballast morphological features, including overall shape and angular distribution, remains a hot issue in research on ballast mechanical behavior simulation. A novel shape reconstruction method was adopted to generate...journal article 2023
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Zhang, A. (author), Dieudonné, A.A.M. (author)Microbially induced carbonate precipitation is a promising ground improvement technique which can enhance the mechanical properties of soils through the precipitation of calcium carbonate. Experimental evidences indicate that the precipitated carbonate can display different distribution patterns. Crystals can develop at grain–grain contacts ...journal article 2023
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Yang, Fan (author), Zhang, P. (author), Wang, Yuan (author), Wei, Kai (author), Dong, Liwei (author), Wang, Ping (author)The coupled vehicle-track system (CVTS) dynamics have been extensively investigated for decades. However, the calculation accuracy of prevailing vehicle-track coupling models needs to be improved in the high frequency range due to the inappropriate model simplification and neglect of material nonlinearity. In this study, we propose a refined...journal article 2023
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Zhang, J. (author)Cracks, which could nucleate and propagate in engineering structures, could have an adverse effect on mechanical performance and even lead to catastrophic failure. Thus, it is critical to investigate structural behavior under fracture, which requires an appropriate modeling methodology for fracture analysis. Furthermore, designing structures...doctoral thesis 2022
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Zhang, Y. (author)Structure-conserving numerical methods that aim at preserving certain structures of the PDEs at the discrete level have been an interesting research topic for many decades. The mimetic spectral element method, a recently developed arbitrary order structure-preserving method on orthogonal or curvilinear meshes, has also been drawing increasingly...doctoral thesis 2022
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Lai, F. (author), Zhang, Ningning (author), Liu, Songyu (author), Yang, Dayu (author)Active earth pressure on retaining structures supporting a narrow column of soil cannot be properly analysed using Coulomb's theory. Finite element limit analysis (FELA) shows that the soil form multiple failure surfaces if the soil column is sufficiently narrow. This paper proposes a framework for active earth pressure estimation for narrow...journal article 2022