This paper systematically reviews the breakthrough achievements of Professor Wang Jinwu’s research team in digital diagnosis and treatment of limb osteoarthritis (OA). Addressing key challenges in conventional OA management, such as difficulties in early screening, the lack of biomechanically adaptive stepwise treatment strategies, and the disconnect between surgery and postoperative rehabilitation, the team has developed a novel “screening-treatment-rehabilitation” model through interdisciplinary integration of medicine and engineering supported by digital technologies. Specifically, they developed a biplanar fluoroscopy system for precise dynamic screening, proposed the theory of “joint unloading mechanical correction”, and implemented precision treatment through the integration of 3D-printed personalized orthoses, stem cell enrichment techniques, and customized prostheses. In addition, they pioneered an Internet of Things (IoT)-based remote cloud rehabilitation network. Although this framework still requires further optimization regarding micro-metabolic mechanism coupling and industrial cost reduction, deeper integration with cutting-edge technologies such as organoids and digital twins in the future is expected to drive OA diagnosis and treatment toward a new stage of multidimensional precision medicine, demonstrating the profound value of medical-engineering integration in advancing human health.

The field of minimally invasive laparoscopic surgery is undergoing a significant paradigm shift from multi-port to single-port access, driven by the imperative to further reduce patient trauma. This transition, however, introduces critical technical bottlenecks, particularly in achieving high-payload dexterous manipulation and effective kinematic decoupling of multiple instruments within severely constrained intra-abdominal spaces. This review provides a systematic analysis of the first domestically developed single-port surgical robotic platform (SHURUI), led by Professor Xu Kai at Shanghai Jiao Tong University and approved by the National Medical Products Administration (NMPA). From a mechanism design perspective, this review examines the innovative dual-continuum mechanism that has enabled the system to overcome international technological monopolies. Particular emphasis is placed on the rigid-flexible coupling architecture, which achieves an effective balance between high payload capacity and enhanced dexterity through an ultra-compact diameter of 12 mm access port, while demonstrating versatility across multi-port, single-port, and hybrid-port surgical configurations. At the modelling and perception levels, it traces key advancements, including the transition from conventional constant-curvature kinematic assumptions to more sophisticated variable-curvature dynamic compensation strategies, as well as the progression from markerless visual tracking to intelligent assisted perception frameworks. Building upon these innovations, it critically evaluates persistent limitations and future challenges, including nonlinear distortion under complex loading conditions, the absence of high-fidelity haptic feedback, and the need for more extensive long-term clinical evidence. In conclusion, the SHURUI system and the foundational research led by Professor Xu mark a landmark milestone in single-port surgical robotics, achieving core mechanism autonomy, overcoming longstanding international technological barriers, and enabling successful clinical translation. The field currently stands at a critical inflection point, poised to transition from conventional passive master-slave teleoperation tools to active, intelligent surgical platforms. Future advancements should prioritize the deep integration of multimodal sensing and artificial intelligence-driven decision-making architectures, facilitating the evolutionary leap from remote-controlled operation to autonomous intelligence. This trajectory will ultimately propel minimally invasive endoscopic surgical robotics toward a new paradigm of intelligent collaborative systems.

The time-domain calculation method for the dynamic response of floating wind turbines under the combined action of wind, waves, and flow has been extensively researched and developed. However, due to its low computational efficiency, substantial computational resources are required when applying this method to optimize the layout of units in a floating wind farm and to optimize the preliminary design of floating wind turbines and mooring systems. Therefore, this paper focuses on the frequency-domain analysis method enabling rapid calculation of the dynamic response of floating wind turbines. It comprehensively considers various environmental load factors, including first- and second-order wave loads, pulsating wind loads on the turbine, slender member viscous loads, mooring systems, and wind turbine pitch control strategies. For different operating conditions such as below-rated operation, pitch operation, and shutdown, the results obtained from the frequency-domain method were compared and analyzed with the time-domain prediction results from OrcaFlex software. Both methods show good consistency in terms of steady-state response, dynamic response spectra, and statistical values, thus validating the applicability and accuracy of the frequency-domain analysis method in providing reliable reference value for the preliminary design and parameter sensitivity analysis of floating wind turbines. Furthermore, based on the frequency-domain method, the influence of wind-wave parameters, second-order wave forces, and the implementation of wind turbine control strategies on the dynamic response characteristics of floating wind turbines was studied.

To accurately predict the joint distribution of short-term wave height and period, this paper proposes a new model based on the conditional probability approach. In this model, wave height follows a two-parameter Weibull distribution, while the conditional period distribution is characterized by a log-normal distribution. To incorporate the influence of wave spectral shape, the broad-width Wallops spectrum is adopted, and the corresponding model parameters are derived. Simulations are conducted using both the Wallops spectrum and measured wave spectra as target spectra to obtain the wave height-period joint distribution. Taking the simulated data as a benchmark, the proposed model is compared with five commonly used joint distribution models. Additionally, the wave height and period distributions are analyzed, with the sources of prediction errors discussed. The results indicate that the model proposed closely matches the simulated data for both Wallops and measured spectra, whereas the other five models only perform well in specific cases. Moreover, this model takes an explicit closed-form expression, making it applicable to non-Gaussian wave conditions.

As a core component of underwater production facilities, subsea jumpers are prone to vortex-induced vibration (VIV) in the ocean currents, which can cause structural fatigue damage. However, limited experimental research on VIV of jumpers has left a gap in understanding the VIV response characteristics. To address this gap, an out-of-plane VIV experiment of a π-shaped jumper is conducted in uniform flow, aiming to mechanistically investigate its VIV behavior. Strain data under different flow velocities are analyzed using common methods such as modal analysis and wavelet transform. The results show that the π-shaped jumper exhibits dominant frequency ratios of 3 and 4 between the in-line (IL) and cross-flow (CF) directions, differing from those of a single riser in out-of-plane uniform flow. As flow velocity increases, the strain amplitudes in both IL and CF directions follow a variation pattern resembling an inverted quadratic curve under the dominant mode, with their peak values coinciding at the same flow velocity.

To explore the effect of tip skew coupled rake on the hydrodynamic performance of Kappel propellers, the fourth-order B-spline method was used to design and change the radial distribution of Kappel propellers in the skew and rake, and an 8-type propeller was constructed. The SST k-ω+γ transition turbulence model, where k denotes the turbulent kinetic energy, ω the specific dissipation rate, and γ the intermittency factor, was employed for simulation, with the Kap509 propeller serving to validate the accuracy of the simulation. The numerical results of the propeller’s open water efficiency are 1.06% to 2.50% lower than the experimental data. It is found that in the vicinity of J=0.8, except for conventional end-plate propellers, the efficiency of the Kap01 series propellers is consistently higher than that of the Kap02 series, with an average increase of 3%. This effect is most pronounced when the skew is 24°, where the efficiency rises by 4.78%. The propeller efficiency increases with the increase of skew when J=0.9-1.0. Under low rake radial distribution, the skew of the propeller can be appropriately improved, which can strengthen the end-plate effect of the Kappel propeller, thereby improving the propulsion performance of the Kappel propeller.

To study the cavitation characteristics of propellers under oblique flow conditions and quantitatively analyze the blade cavitation area, this paper takes the PC456 propeller model as the research object. Based on the OpenFOAM platform, the cavitation performance of the PC456 propellers under oblique flow is numerically calculated using the SST k-ω turbulence model and Schnerr-Sauer cavitation model. The results show that the influence of oblique flow on the hydrodynamic performance of the propeller cavitation increases with the increase of the oblique flow angle. Within the phase range of [-90°, 40° ], the cavitation area of the blade reaches its maximum at the -20° phase, and as the oblique angle increases, the amplitude of the change in bubble area also increases. In addition, the numerically predicted cavitation areas are in good agreement with the experimental results, especially under conditions of low cavitation numbers, which validates the effectiveness of the numerical method used in this study.

To address the trajectory tracking control problem of azimuth stern drive tug, a three-degree-of-freedom motion data-driven model of the tug is developed by using gated recurrent unit (GRU) neural network, and a model predictive control (MPC) trajectory tracking controller is designed based on the GRU model to overcome the limitations of the traditional control methods that rely on the precise system mechanism model. This controller regulates the tug speed and heading by adjusting the left and right rudder angles without changing the tug propeller speed. Simulation experiments are conducted to validate the effectiveness of the proposed scheme, showing that the model achieves satisfactory accuracy even under noise interference. Furthermore, by comparing the control performance under different prediction step sizes, the influences of these parameters on the control effect and solution time are explored. Due to the increase in the complexity of the optimization solution, when the prediction horizon increases, the control accuracy improves, but the solution time also rises. This study provides new ideas for the precise trajectory tracking control of tugs, and offers valuable references for the control of similar nonlinear systems.

Thrust allocation serves as a critical means for achieving vector propulsion in unmanned surface vessels (USV) equipped with dual waterjet thrusters. However, existing thrust allocation methods employed in vessels featuring azimuth thrusters fail to address the resolution of vector forces for dual waterjet propulsion, due to characteristics such as thrust angle limitations and reverse thrust. To achieve vector motion control of a dual waterjet propelled USV, a hierarchical optimization-based thrust allocation algorithm is proposed. In the first tier, a vector synthesis approach incorporating enhanced angle constraints is utilized to acquire top-tier vector thrust satisfying constraints on the rotating range and rate characteristics of the thrusters. In the second tier, leveraging the top-tier vector thrust values as inputs and considering constraints on thruster power and power change frequency, an optimization method based on seeking minimal distance is proposed. This method facilitates the allocation of reverse thrust angles and nozzle flow velocities for waterjet thrusters, thereby resolving singular issues in dual waterjet thrust allocation. Simulation experiments and the semi-physical simulation experiments validate the effectiveness of the hierarchical optimization-based thrust allocation algorithm for dual waterjet thrusters. The results indicate that this method enables efficient thrust allocation for dual waterjet thrusters, while concurrently limiting fluctuations in thruster power frequency and amplitude during expected thrust variations, thereby reducing shafting wear while achieving target vector thrust.

Anchorage and submarine cables are crucial maritime facilities safeguarding sea traffic and communication. However, anchoring and dragging anchors in anchorage areas may pose risks for damaging nearby submarine cables. This paper scientifically analyzes the factors contributing to submarine cable damage from the perspectives of vessels, environment, personnel, and cables. Starting from the causes of damage, the anchoring failure and drifting process is simulated by incorporating the internal and external factors of anchor penetration depth, vessel type, and crew decision-making during emergencies. A risk model for submarine cable damage is developed, with a case study conducted on the Luxi Dao pilot quarantine anchorage in Wenzhou Port and its surrounding submarine cables. The study reveals that the risk of cable damage depends on vessel-cable distance, vessel type, and vessel scale. The model provides a quantitative analysis method for the interaction between anchorage and submarine cable, investigates cable damage from multiple angles, and offers valuable support for safe maritime operations.

To investigate the degradation laws and deterioration mechanisms of interlaminar shear strength (ILSS) of glass fiber reinforced polymer (GFRP) rebars with different matrices in seawater and sea-sand concrete (SWSSC) environment, an accelerated corrosion test was conducted on epoxy-based and vinyl ester-based GFRP rebar specimens in a simulated SWSSC pore solution, and then the ILSS tests and scanning electron microscope (SEM) tests were conducted. For epoxy-based GFRP rebars, two kinds of curing agents naming MHHPA and MDA were adopted. The results indicate that the uncorroded MHHPA cured epoxy-based GFRP rebars possesse the highest initial ILSS (42.44 MPa), followed by the vinyl ester-based GFRP rebars (37.10 MPa), while the MDA cured epoxy-based GFRP rebars have the lowest initial ILSS (27.20 MPa). After immersion in a 55 ℃ pore solution environment for 84 d, the ILSS retention of MHHPA cured epoxy-based GFRP rebars is 7.43% while the ILSS retention of MDA cured epoxy-based GFRP and vinyl ester-based GFRP rebars are 39.51% and 71.06% respectively. With the increase in temperature and immersion time in the SWSSC simulated pore solution, the ILSS of three kinds of GFRP rebars all show a declining trend. The reasons for the degradation of ILSS are the interfacial debonding between fibers and matrix and the hydrolytic loss of the matrix. Among the tested specimens, the vinyl ester-based GFRP rebars exhibit the strongest resistance to corrosion in the simulated SWSSC pore solution, while the MHHPA cured epoxy-based GFRP rebars show the weakest resistance with the MDA cured epoxy-based GFRP rebars being intermediate.

In the field of geotechnical engineering, it is of great significance to analyze the law and mechanism of soil hydraulic fracturing, which can provide a basis for the study of the diffusion and distribution of splitting grouting veins and guide practical engineering. In this paper, a three-dimensional finite element program is developed by using block diagonal preprocessing, preconditioned symmetric quasi-minimal residual (PSQMR) iterative method, and improved sparse matrix vector multiplication parallel algorithm, which enables large-scale Biot consolidation finite element calculation, realizing the finite element solution based on CPU serial computing platform and GPU parallel computing platform, greatly improving the calculation scale, and accomplishing large scale finite element calculation on personal computer. By comparing the numerical simulation results, experimental simulation results, and theoretical analysis with the calculation results, the correctness of the calculation method is verified, which provides a numerical simulation tool for the study of hydraulic fracturing in soil.

This paper explores the seismic response differences between cutting slopes and embankment slopes, with a particular focus on the impact of initial water content on the seismic performance of unsaturated slopes. To achieve this, a soil-water-air three-phase coupled numerical analysis method is developed within the framework of unsaturated soil mechanics. This numerical approach is employed to simulate the deformation patterns and acceleration responses of both slope types during an earthquake. Additionally, the influence of initial water content on the dynamic behavior of the slopes is examined. The results indicate that high initial water content reduces the risk of sliding failure in cut slopes due to the stabilizing effect of the adjacent undisturbed ground. Embankment slopes exhibit a more pronounced sliding tendency, with greater displacement observed at the slope toe.

The honeycomb at the inner band of a compressor stator and the labyrinth on the disk form a sealed cavity, in which the clearance leakage flow has a key impact on the aerodynamic performance of the axial flow compressor. In this paper, focusing on the first 1.5-stage of a low-speed research compressor, numerical simulations are conducted to compare the impact of honeycomb seal structure and slide wall on the aerodynamic performance of the compressor, as well as the performance changes of honeycomb seal structure under two different labyrinth seal clearance conditions. The performance calculation results show that the isentropic efficiency of the compressor equipped with the 0.2-mm-clearance honeycomb cavity model is slightly lower than that of the slide-wall cavity model, which is attributed to the elevated total temperature rise induced by the leakage flow inside the cavity. Comparative analysis of cavity leakage flow characteristics and detailed flow field investigation indicate that honeycomb structure induces a simultaneous increase in both the cavity leakage flow rate and swirl angle. A strong interaction is observed between the airflow within the cavity and the honeycomb structure, creating a complex vortex flow that significantly elevates the total temperature in both the seal cavity and the honeycomb itself. This temperature elevation ultimately leads to a reduction in compressor efficiency. In contrast, when the zero-clearance honeycomb model is compared with the 0.2-mm-clearance honeycomb model, the decreased total temperature ratio contributes to an improvement in isentropic efficiency. In the zero-clearance model, although the average total temperature of the leakage flow rises owing to the reduced clearance, the compressor efficiency is enhanced by the substantial reduction in leakage flow rate. The findings in this paper clarify the quantitative relationship and influence mechanism of leakage flow under different clearance conditions on the performance of the honeycomb and labyrinth seal structure applied to the compressor stator, which therefore provide certain references for the engineering design of honeycomb seal cavities.

To support the airworthiness certification of aircraft engines regarding CCAR 33.63 provisions, a three-dimensional contact dynamics-based computational model for fan blade-flexible casing rubbing vibration was established. Modal reduction was employed to reduce the size of the computational model, while a cubic B-spline surface fitting technique was utilized to enhance the discretization accuracy of the casing inner surface. A bilinear elastic-plastic model was adopted to describe the rubbing mechanical properties of the abradable coating, and contact forces between blades and casings were calculated based on coating wear depth, blade thickness, and element shape functions. Using this model, the rubbing response characteristics between fan blades and flexible casings were investigated. The results showed that blade damping is a key factor affecting rubbing vibration response. For blades with lower damping, in addition to coupling vibrations between blade-casing single nodal diameter modes during rubbing process, there also exist blade-casing coupled vibrations caused by traveling waves associated with multi-nodal diameter modes of casings. The variations in contact strength during rubbing process leading to changes in dynamic characteristics of components cause the above interactions. The dynamic model established in this paper provides a new approach for identifying and evaluating blade-casing rubbing coupled vibrations.

An image-driven model based on spatiotemporal neural network (STNN) is proposed for prediction of crack growth in aluminum alloy. Fatigue experiments with an initial edge crack angle of 0° and a 15.0% limit load level are designed, and images of specimen deformation are captured using digital image correlation (DIC) resulting in 5 511 frames of displacement field data used as datasets of STNN after interpolation, augmentation, and dimension-raising. Two neural netwroks, convolutional long short-term memory (Conv-LSTM) and SimVP, are employed to predict the fatigue crack growth, with their prediction accuracies further compared based on the structural similarity index measure (SSIM) and the root mean square error (RMSE). The results show that the SimVP neural network performs better in the test stage predicting fatigue crack growth rate and propagation path. This method provides a reference for damage tolerance analysis and determination of inspection intervals for structures.