Zhenzhong Hu

    He received both his BE and PhD degree in the Department of Civil Engineering at Tsinghua University, China. He was a visiting researcher in Carnegie Mellon University.
    He is now the associate professor in Shenzhen International Graduate School, Tsinghua University, and also the secretary general of the BIM Specialty Committee of the China Graphics Society.
    His research interests include information technologies in civil and marine engineering, building information modeling (BIM) and digital disaster prevention and mitigation.
  • 2024-02-27

    2024-02-27

    Inertia load reduction for loadoff during floating offshore wind turbine installation: Release decision and ballast control has been published in the journal Sustainable Horizons.

    High offshore installation costs are a significant factor limiting the competitiveness of offshore wind energy. One efficient installation approach for floating offshore wind turbines is to preassemble the tower, nacelle, and rotor onshore and perform a single lifting operation to mate the superstructure with the floating foundation at the installation site. It is heavy lifting, due to the weighty payload. At the end of the mating process, a loadoff operation is conducted to transfer the preassembly to the floating foundation. It results in a sudden change in total force acting on the vessel and causes substantial acceleration and potential damage to the mechanism in the onboard nacelles. The magnitude of acceleration of the onboard nacelles can vary greatly at different release instants. In this research, a simplified two-degrees-of-freedom (DOF) (heave and pitch) model is also proposed to account for the heavy lifting process and variable ballast tanks. The sudden payload transfer is approximated using a hyperbolic tangent function to guarantee continuity and differentiability. The loadoff operation consists of the decision-making and vessel-stabilizing phases. Based on the nonlinear model predictive control method, a payload-transfer time selector and anti-pitch ballast controller have been developed to achieve optimal release time decisions and stabilize the vessel after payload release, respectively. Six-DOF simulation results show that the proposed algorithms are capable to a satisfying level of robustness of deciding the optimal payload release time instant, as well as limiting the peak and mean acceleration magnitudes of the onboard nacelles after payload release. The decision-making and control strategies may promote the sustainable energy transformation by extending the operation window and reduce the installation costs.

    Note: The first author of this paper is Ma Can, a master's student in 2021, and Assistant Professor Ren Zhengru is the corresponding author. The research results were supported by Shen-zhen Science and Technology Program, Shen-zhen Science & Technology Commission, and Shenzhen Science and  the Guangdong Basic and Applied Basic Research Foundation.

  • 2024-02-19

    2024-02-19

    The Probability of Ship Collision during the Fully Submerged Towing Process of Floating Offshore Wind Turbines have been published in the journal Sustainability.

    In the context of the rapid development of the green energy industry, the Floating Offshore Wind Turbines (FOWTs)  project is the focus of the current green sustainable development of energy. However, most studies have focused on the design and manufacture of the Wind Turbines before installation and the movement and response after installation, and have studied less the collision risk that is most likely to occur during the towing of the FOWTs to the site. Based on the analytical model construction method, this study takes the Wanning Floating Offshore Wind Farm (FOWF)  as the research object, expands on the widely recognized Pedersen collision probability assessment model, and creatively develops the probability assessment calculation model of collision with other ships during the towed transport of FOWTs in non-channel areas. The results show that the probability of ship collision in towed transport is mainly affected by regional ship density, distribution and sailing speed. This study makes up the gap in the field of risk assessment during installation of deep-water FOWTs.

    Note: The first author of this paper is Li Yihong, a postdoc, and I am the corresponding author. The authors also include Liu Longxiang, a master's student, and Associate Professor Li Sunwei. The research results were supported by Guangdong Basic and Applied Basic Research Foundation and Shenzhen Science and Technology Commission.

  • 2024-01-30

    2024-01-30

    "A mechanical analysis method and system for fan installation based on digital twin" has obtained the invention patent certificate (patent number: ZL202311306512.6).

    The invention discloses a mechanical analysis method and system for fan installation based on digital twin, which comprises the following steps: obtaining the basic information of the rod structure; According to the basic information of the bar structure, a bar element set and a load set are generated; According to the bar element set and the load set, the global stiffness matrix and the external load vector in the compressed sparse row matrix format are integrated. According to the global stiffness matrix and the external load vector, the global displacement vector is obtained by the conjugate gradient method. According to the global displacement vector, a set of deformed member elements is obtained. According to the set of deformed bar elements, the stress distribution results of the bar structure are obtained. The invention accelerates the storage and solving efficiency of the matrix without loss of effective information, so that the calculation accuracy can be taken into account while the calculation efficiency can be effectively improved, and the rapid modeling and calculation of complex and large structures can be realized.

    Note: The inventors of this patent also include doctoral student Min Yantao, Academician Zhang Jianmin, doctoral student Liu Yi, master student Ning Houchun, Associate Professor Li Sunwei and Associate Professor Li Binbin.

  • 2024-01-18

    2024-01-18

    From January 18 to 19, the first "Qingqing Forum" hosted by the Chinese Academy of Ocean Engineering (Qingdao) was successfully held in Qingdao by Academician Zhang Jianmin, Dean of the Institute of Ocean Engineering, Tsinghua SIGS. With the theme of "Building a future competitive advantage in the field of Marine engineering science and technology", the forum focused on topics such as digital intelligence of Marine industry, implementation plan of industrial software localization, research and development and industrialization of high-end Marine equipment, aiming to promote the efficient combination of the strategy of "Tsinghua University Engineering going to the sea" and the Marine science and technology industry foundation and application scenarios in Qingdao and even Shandong.

    On the afternoon of the 18th, the delegation went to the China Academy of Ocean Engineering (Qingdao) to participate in the exchange meeting. The meeting brought together more than 40 teachers from the headquarters of Tsinghua University and our college, as well as nearly 100 leaders, experts and scholars from the Qingdao Municipal government, the Institute of Oceanology of the Chinese Academy of Sciences, and the Chinese Academy of Ocean Engineering (Qingdao). I made a special report entitled "Intelligent engineering Design of offshore engineering". On the morning of the 19th, the delegation went to the Institute of Oceanology of the Chinese Academy of Sciences for exchange, and I shared my report at the seminar. In the afternoon of the same day, the delegation visited Laoshan Laboratory and shared their experience in the subsequent academic exchange meeting.

    The successful holding of the first "Qingqing Forum" not only built a good platform for the deep integration of the Marine science and technology industry of Tsinghua University and Qingdao and even Shandong, but also created new opportunities for the cooperation between the Institute and other scientific research institutions and enterprises.

  • 2023-12-31

    2023-12-31

    On December 24, 2023, the founding meeting of the eighth Editorial Committee and the first working meeting of the Journal of Graphics was successfully held in Beijing. The conference brought together leaders, guests, editorial board members and editorial department members from all over the country, a total of 66 people attended.

    At the meeting, Professor Zhao Gang, chairman of the China Graphics Society, and Professor Wang Guoping, chief editor, successively announced the list of chief editor and deputy editor of the eighth Editorial Board of the Journal of Graphics, as well as the list of editorial board consultants and editorial board members, and issued a letter of appointment for the new incumbents. Among them, I am very honored to be awarded the honor of my excellent editorial board, and re-elected as one of the members of the eighth editorial board. This honor and appointment is not only a recognition of my personal academic ability, but also a recognition of my active exploration in the field, and I will continue to work with other outstanding scholars to participate in the editorial work of the journal, committed to providing high-quality academic content.

    This meeting not only marks the formal establishment of the new editorial board, but also lays a solid foundation for the future development of the journal. Under the leadership of the new editorial Board, we will work together to continuously improve the academic level of the journal to meet the needs of readers in the field of graphics. We will adhere to the principles of academic rigor and innovation, and strive to promote the progress of academic research in graphics, and present more influential academic results to readers.