Rapid Loading Research Articles

Youth and Adolescent Athlete Musculoskeletal Health: Dietary and Nutritional Strategies to Optimise Injury Prevention and Support Recovery

Background: Despite the well-documented benefits of exercise and sports participation, young athletes are particularly vulnerable to musculoskeletal injuries. This is especially true during periods of rapid growth, sports specialisation, and high training loads. While injuries are an inevitable aspect of sports participation, the risk can be minimised by promoting the development of strong, resilient tissues through proper nutrition and injury prevention strategies. Moreover, targeted nutrition strategies can accelerate recovery and rehabilitation, allowing for a quicker return to sports participation. Methods: This narrative review synthesises scientific evidence with practical insights to offer comprehensive dietary recommendations aimed at strengthening tissues and supporting the healing process during recovery and rehabilitation. The selection of all sources cited and synthesised in this narrative review were agreed upon by contributing author consensus, experts in sports nutrition (R.A., H.V., B.D.) and exercise and sports medicine (M.H.). Results: Key topics include factors that contribute to injury susceptibility, general dietary recommendations for growth and development, sports nutrition guidelines, and nutrition considerations during injury and rehabilitation. This review also addresses external factors that may lead to suboptimal nutrition, such as food literacy and eating disorders. Conclusions: By highlighting these factors, this article aims to equip coaches, nutritionists, dietitians, athletic trainers, physical therapists, parents/guardians, sporting organisations, and schools with essential knowledge to implement effective nutritional strategies for injury prevention, recovery, and rehabilitation, ultimately enhancing long-term health and athletic performance.

Genetic Algorithm Optimization in Ship Rapid Loading Planning

Genetic Algorithm Optimization in Ship Rapid Loading Planning

Study on control strategies of the MW-scale supercritical CO2 recompression Brayton cycle for lead-cooled fast reactor

The supercritical CO2 (sCO2) Brayton cycle for the lead-cooled fast reactor (LFR) is an ideal power generation system for the distributed energy supply in remote islands. To figure out the optimal operating modes of the MW-scale sCO2 LFR unit in different load demands, this work performs a dynamic simulation based on the developed control modules. A parametric analysis is conducted about the effects of rotational speed, split ratio, and main gas temperature on the dynamic characteristics. Control strategies are further studied based on the thermodynamic performance and safety under four variable temperature load regulation modes and three fixed temperature rapid load regulation modes. Results show that the tracking αopt mode has the highest average net efficiency (ηnetav) of 19.13 %. The tracking αsafe mode allows compressors to operate in the safest range by sacrificing a little ηnetav. Excellent load change rates are revealed by using the main circuit regulating valve control mode and the turbine bypass control mode, with −12.48 %Pe/min & 11.92 %Pe/min, and −8.25 %Pe/min & 9.70 %Pe/min, respectively. Though the load change rate of the RS control mode is −3.96 %Pe/min & 3.47 %Pe/min, its ηnetav is higher. Our work guides the efficient, flexible, and safe operation of the sCO2 LFR unit.

A 500 kW hydrogen fuel cell-powered vessel: From concept to sailing

This paper presents the “Three Gorges Hydrogen Boat No. 1”, a novel green hydrogen-powered vessel that has been successfully delivered and is currently sailing. This vessel, integrated with a hydrogen production and bunkering station at its dedicated dock, achieves zero-carbon emissions. It stores 240 kg of 35 MPa gaseous hydrogen and has a fuel cell system rated at 500 kW. We analysed the engineering details of the marine hydrogen system, including hydrogen bunkering, storage, supply, fuel cell, and the hybrid power system with lithium-ion batteries. In the first bunkering trial, the vessel was safely refuelled with 200 kg of gaseous hydrogen in 156 min via a bunkering station 13 m above the water surface. The maximum hydrogen pressure and temperature recorded during bunkering were 35.05 MPa and 39.04 °C, respectively, demonstrating safe and reliable shore-to-ship bunkering. For the sea trial, the marine hydrogen system operated successfully during a 3-h voyage, achieving a maximum speed of 28.15 km/h (15.2 knots) at rated propulsion power. The vessel exhibited minimal noise and vibration, and its dynamic response met load change requirements. To prevent rapid load changes to the fuel cells, 68 s were used to reach 483 kW from startup, and 62 s from 480 kW to zero. The successful bunkering and operation of this hydrogen-powered vessel demonstrates the feasibility of zero-carbon emission maritime transport. However, four lessons were identified concerning bunkering speed, hydrogen cylinder leakage, hydrogen pressure regulator malfunctions, and fuel cell room space. The novelty of this work lies in the practical demonstration of a fully operational, hydrogen-powered maritime vessel achieving zero emissions, encompassing its design, building, operation, and lessons learned. These parameters and findings can be used as a baseline for further engineering research.

Dynamic buckling active control of FGM spherical shell with piezoelectric sensor and actuator layers

The mechanical snap-through phenomenon represents one of the buckling modes inherent in shallow shells, exemplifying the shell's reaction to external loads, which can potentially have detrimental effects on structural performance. This article delves into the study of this phenomenon within the context of spherical shells. Leveraging functionally graded material (FGM) in the main layer of this structure proves instrumental in enhancing the shell's performance against rapid mechanical loads. Furthermore, the strategic placement of piezoelectric layers, both symmetrically and asymmetrically, coupled with the implementation of a proportional and derivative control system, facilitates the control of the shell's response. The formulation of displacement field and electric potential is grounded in the first-order shear deformation theory (FSDT) and second-order distribution, respectively. The strong form of nonlinear dynamic and electrostatic equations is derived using Hamilton's principle. Solving these equations is achieved through the implementation of the generalized differential quadrature (GDQ) method in the spatial domain and Newmark in the time domain. Additionally, the Newton-Raphson method is employed to tackle the inherent nonlinearity of the problem. The Budiansky's criterion is employed for the assessment of the load necessary for the buckling of the shell. Following the validation of results against numerical, analytical, and laboratory outcomes, a set of parametric results is presented. These results underscore the remarkable impact of the control system in mitigating shell deformation under time-dependent mechanical loads, as well as in postponing the occurrence of the snap-through phenomenon and damping the vibrations.

Techno economic analysis and performance based ranking of 3–200 kW fuel flexible micro gas turbines running on 100% hydrogen, hydrogen fuel blends, and natural gas

Micro gas turbines ranging from 3 to 200 kW are vital for decentralized power generation due to their reliability, rapid load response, and adaptability to 100% hydrogen and hydrogen fuel blends. This paper conducts a techno-economic assessment of MGTs powered by hydrogen, focusing on their environmental, economic, and technical viability. Key factors include the transition from natural gas to hydrogen to achieve net-zero emissions and enhance grid stability. Despite hydrogen's higher initial costs, its declining production costs and cleaner combustion make it a promising alternative. The study utilizes five micro gas turbine models (3, 30, 65, 100, and 200 kW) to evaluate a techno-economic analysis using 100% hydrogen, a 30% hydrogen and 70% natural gas blend, and 100% natural gas as fuels. Technical results are supported by experimental data from the world's first 100% hydrogen-fired micro gas turbine unit in Stavanger, Norway. Standard cost estimations for capital, operation and maintenance, and fuel costs are provided. The study introduces a novel technique for cost estimation and assesses econometric indicators such as net present value, internal rate of return, return on investment, payback period, and cost-benefit analysis. It compares economic scenarios for 2024, 2030, and 2040, highlighting the impact of fuel price volatility and regulatory changes on micro gas turbine techno-economics. Micro gas turbines are ranked using the Technique for Order Preference by Similarity to Ideal Solution-Multi-Criteria Decision Making (TOPSIS-MCDM) method based on their techno-economic performance. The ranking of microturbines based on techno-economic analysis performance is a novel contribution of this paper. Finally, a sensitivity analysis on the five micro gas turbines is carried out by changing the hydrogen fuel price. This research provides a comprehensive framework for stakeholders to make informed investment decisions, ensuring a smooth transition to 100% hydrogen-based power generation. The findings support the adoption of hydrogen and natural gas blends as an interim solution towards achieving a hydrogen economy.

Histamine synthesis and transport are coupled in axon terminals via a dual quality control system

Monoamine neurotransmitters generated by de novo synthesis are rapidly transported and stored into synaptic vesicles at axon terminals. This transport is essential both for sustaining synaptic transmission and for limiting the toxic effects of monoamines. Here, synthesis of the monoamine histamine by histidine decarboxylase (HDC) and subsequent loading of histamine into synaptic vesicles are shown to be physically and functionally coupled within Drosophila photoreceptor terminals. This process requires HDC anchoring to synaptic vesicles via interactions with N-ethylmaleimide-sensitive fusion protein 1 (NSF1). Disassociating HDC from synaptic vesicles disrupts visual synaptic transmission and causes somatic accumulation of histamine, which leads to retinal degeneration. We further identified a proteasome degradation system mediated by the E3 ubiquitin ligase, purity of essence (POE), which clears mislocalized HDC from the soma, thus eliminating the cytotoxic effects of histamine. Taken together, our results reveal a dual mechanism for translocation and degradation of HDC that ensures restriction of histamine synthesis to axonal terminals and at the same time rapid loading into synaptic vesicles. This is crucial for sustaining neurotransmission and protecting against cytotoxic monoamines.

Emulsion-Based Multiscale Structural Design Realizes Lightweight and Superelastic Graphene Aerogels for Electromagnetic Interference Shielding.

Ultralight graphene aerogels with high electrical conductivity and superelasticity are demanded yet difficult to produce. A versatile emulsion-based approach is demonstrate to optimize multiscale structure of lightweight, elastic, and conductive graphene aerogels. By constructing Pickering emulsion using graphene oxide (GO), poly (amic acid) (PAA), and octadeyl amine (ODA), micron-level close-pore structure is realized while thermal shrinkage mismatch between GO and PAA creates numerous nanowrinkles during thermal annealing. GO nanosheets are bridged by PAA-derived carbon, enhancing the structural integrity at molecular level. These multiscale structural features facilitate rapid electron transport and efficient load transfer, conferring graphene aerogels with intriguing mechanical and electromagnetic interference (EMI) shielding properties. The emulsion-based graphene aerogel with an ultralow density of ≈3.0mg cm-3 integrates outstanding electrical conductivity, air-caliber thermal insulation, high EMI shielding effectiveness of 75.0dB, and 90% strain compressibility with superb fatigue resistance. Intriguingly, thanks to the gel-like rheological behavior of the emulsion, ultralight graphene scaffolds with programmable geometries are obtained by 3D printing. This work provides a general approach for the preparation of ultralight and superelastic graphene aerogels with excellent EMI shielding properties, showing broad application prospects in various fields.

Enhancing voltage regulation in high-speed digital circuits: A simulation-based analysis of the modified Ohm's law

Voltage droop is a significant challenge in high-speed digital circuits, impacting the reliability and performance of electronic systems. This paper introduces a novel approach based on a Modified Ohm's Law to address this issue. By incorporating nonlinear resistance effects, the Modified Ohm's Law provides a more accurate representation of circuit behavior, particularly under dynamic conditions. Through a rigorous simulation framework, the behavior of power supply models under varying load conditions is analyzed. The paper systematically examines circuit responses, load variations, and power supply dynamics, integrating both Standard and Modified Ohm's Law to compare their effectiveness in voltage regulation. The simulation results indicate that the Modified Ohm's Law provides a more accurate prediction of voltage behavior, particularly under rapid load changes, leading to significant improvements in voltage stability. The applied parameter sweep analyses reveal that adjusting the time constant of the power supply within the Modified Ohm's Law framework yields superior voltage regulation compared to traditional methods. Additionally, the analysis of frequency and amplitude variations demonstrates the robustness of the Modified Ohm's Law in maintaining voltage stability across different operational scenarios. This approach effectively addresses the nonlinearities in resistance, reducing voltage droop and enhancing the reliability of high-speed digital circuits. The findings demonstrate the potential of the Modified Ohm's Law in practical applications, suggesting further research and real-world experimentation to fully explore its benefits and implementation strategies. This work contributes to the advancement of voltage regulation techniques, offering a robust solution to the persistent problem of voltage droop in modern electronic systems.

Impact toughness of LPBF 316L stainless steel below room temperature

The fracture behavior of LPBF 316L stainless steel in rapid loading conditions was characterized from room to cryogenic temperatures. Instrumented impact toughness tests allow to determine the influence of the microstructural features of this material on its crack initiation and propagation behavior. In the stress-relieved, homogenized/partially recovered and recrystallized states, LPBF 316L exhibit gradual impact toughness decreases between 20 °C and – 193 °C, with close toughness loss ranging from 0.38 to 0.55 J cm−2/°C. These values were similar to those reported by the literature for hot isostatically pressed (0.35–0.58 J cm−2/°C) and wrought (0.45–0.51 J cm−2/°C) 316L stainless steels, meaning that the microstructural features of LPBF 316L (segregations cells, dislocations cells, oxide particles, etc.) did not significantly influence the temperature sensitivity of its fracture properties. Whatever the testing temperature and microstructural state, fully ductile fracture occurred by decohesion at the oxide/matrix interfaces and void growth into dimples. The martensitic transformation during deformation at low temperature did not appears to play a significant role in the temperature sensitivity of the decrease in impact toughness of these materials. The latter is likely a consequence of the loss of ductility of the austenitic matrix, especially, under localized strain conditions.

Experimental Study to Investigate the Performance-Related Properties of Modified Asphalt Concrete Using Nanomaterials Al2O3, SiO2, and TiO2.

The dual nature of asphalt binder necessitates improvements to mitigate rutting and fatigue since it performs as an elastic material under the regime of rapid loading or cold temperatures and as a viscous fluid at elevated temperatures. The present investigation assesses the effectiveness of Nano Alumina (NA), Nano Silica (NS), and Nano Titanium Dioxide (NT) at weight percentages of 0, 2, 4, 6, and 8% in asphalt cement to enhance both asphalt binder and mixture performance. Binder evaluations include tests for consistency, thermal susceptibility, aging, and workability, while mixture assessments focus on Marshall properties, moisture susceptibility, resilient modulus, permanent deformation, and fatigue characteristics. NS notably improves binder viscosity by about 138% and reduces penetration by approximately 40.8% at 8% nanomaterial (NM) content, significantly boosting hardness and consistency. NS also enhances Marshall stability and decreases air voids, increasing the mix's durability. For moisture resistance, NS at 8% NM content elevates the Tensile Strength Ratio (TSR) to 91.0%, substantially surpassing the 80% standard. Similarly, NA and NT also show improved TSR values at 8% NM content, with 88.0% and 84.1%, respectively. Additionally, NS, NA, and NT reduce permanent deformation by 82%, 69%, and 64% at 10,000 cycles at 8% NM content, illustrating their effectiveness in mitigating pavement distress. Notably, while higher NM content generally results in better performance across most tests, the optimal NM content for fatigue resistance is 4% for NS and 6% for both NA and NT, reflecting their peak performance against various types of pavement distresses. These results highlight the significant advantages of nanoparticles in improving asphalt's mechanical properties, workability, stability, and durability. The study recommends further field validation to confirm these laboratory findings and ensure that enhancements translate into tangible improvements in real-world pavement performance and longevity.

Experimental investigation of Lord Kelvin’s isentropic thermoelastic cooling and heating expression for tensile bars in two engineering alloys

ABSTRACT Solids change temperature when rapidly and elastically stressed. The effect proposed by W. Thomson, who was ennobled as Lord Kelvin, is adiabatic thermoelastic cooling or heating depending on the sign of the stress. A highly sensitive radiometrically calibrated, cooled infrared camera was employed to measure temperatures both decreasing and increasing. Temperature measurements made from the reversible, elastic part of the stress–strain curve during rapid uniaxial tensile loading and unloading were investigated. The quasi-isentropic cooling temperature from the stress loading curve is recovered by heating after the specimen fractures when the load is released. These measurements establish for the first-time isentropic temperature recovery. The materials tested are an AISI 4340 steel and an aluminium 2024 alloy. Measurements of the stress cooling are − 0.65 ± 0.05 K/GPa for steel and − 1.8 ± 0.3 K/GPa for aluminium alloy. The thermoelastic heating is − 1.2 ± 0.3 K/GPa for steel and − 1.8 ± 0.2 K/GPa for aluminium. These values are compared to Thomson’s theoretical thermoelastic prediction; comparisons are also made to equations of state tables. The experimental values are below theoretical predictions. The quasi-isentropic, elastic part of the temperature change is fully recovered after extensive plastic deformation by the fracture stress release wave.

RBF-based event-triggered fixed-time stable and chattering-free controller for load following of the pressurized water reactor

Preventing chattering phenomenon in load following control of the Pressurized Water Reactor (PWR) is still a main challenge. This article focuses on the chattering-free and rapid load following control strategy for PWR. Firstly, by proposing a newly adaptive updated law, the Radial Basis Function Neural Networks (RBFNNs) is employed to compensate the unmeasured states of relative delayed neutron precursor density, average fuel temperature and uncertain disturbances simultaneously online. On this basis, a fixed-time stable controller including saturation function is constructed to guarantee that the actual output power (OP) of nuclear reactor can follow the desired power (DP) within a fixed-time and the chattering phenomenon is alleviated. Additionally, to save the limited network resource and reduce the cost of computation, an event-triggered mechanism is constructed. Based on it, a chattering-free fixed-time stable controller is structured to ensure that the actual reactivity of control rod (ARCR) converges to the desired control rod reactivity (DCRR) within a fixed-time, meanwhile, it can eliminate Zeno phenomenon during the control process. Finally, the effectiveness and feasibility of the theoretical results are demonstrated through simulation examples.

Enhancing voltage stability through wavelet-fuzzy control of hydrogen flow in OC-PEM fuel cell

Open cathode proton exchange membrane fuel cells (OC-PEM fuel cells) serve as electricity generators, utilizing hydrogen as an input source. While effective for fixed loads like residential applications, challenges arise in dealing with output voltage fluctuations caused by rapid load changes. These fluctuations not only impact fuel cell performance but also introduce instability in the supplied power. To solve this issue, the study proposes an innovative hydrogen flow control system employing a feedforward wavelet- fuzzy method. The primary goal of this control system is to enhance fuzzy control performance using wavelets, mitigating signal fluctuations and achieving optimal stability in fuel cell output voltage under constant load conditions. Wavelet functions act as filters on the fuzzy control input, minimizing fluctuations and refining the entire process. Additionally, a feedforward system is incorporated to maintain hydrogen flow at the set point value. The proposed control system is implemented on a validated model using experimental data. Performance analysis reveals that the proposed method effectively stabilizes voltage by accelerating the recovery time from disturbances.

Enhanced perturb and observe control for addressing power loss under rapid load changes using a buck–boost converter

Many researchers have focused on improving the efficiency of photovoltaic (PV) systems by enhancing their control mechanisms to more consistently operate in the PV panels’ maximum power points. The predominant method used in these studies is the Perturb and Observe (P&O) method. However, this method faces challenges of drift when encountering rapid changes in resistive load, which completely inhibits them from addressing the problem of power loss. Additionally, the traditional P&O method suffers from oscillation issues. Here, an innovative control method is presented to improve the duty cycle and enable the handling of the challenges associated with sudden and rapid changes in resistive loads. A buck-boost power converter is implemented as an impedance adaptor to maintain operation at the maximum power point. The efficiency of the proposed modified P&O algorithm was evaluated using MATLAB software and compared to the traditional P&O algorithm across various operating scenarios. The simulation results show that the proposed method is significantly more efficient and effective than the traditional P&O algorithm, indicating its potential to enhance the efficiency of PV systems and increase their ability to adapt to changes in resistive load.

A novel development of an unmanned surface vehicle directly powered by an air-cooled proton exchange membrane fuel cell stack

Most compact Unmanned Surface Vehicles (USVs) used in water quality monitoring and maritime surveillance rely on lithium batteries. However, they're only ideal for short missions. This paper first fabricates a novel lightweight, air-cooled, high-power-density Proton Exchange Membrane Fuel Cell (PEMFC) stack with ultrathin steel bipolar plates as the primary power source for a self-made compact USV. This stack consists of 40 single cells and integrates a reliable air-cooled system, operating in parallel with a supercapacitor to enhance its performance. Experimental results show that this PEMFC-powered USV outperforms the main lithium battery-powered counterpart, offering an extended cruising range and better power stability and significantly increasing the cruising range from 8 km to 38 km when the PEMFC stack and the main lithium battery are of similar volume and weight. Integrating a low voltage purging logic with a 0.4 V threshold in the dead-end anode (DEA) mode results in a remarkable hydrogen utilization rate of up to 98%. Moreover, the average voltage of the PEMFC stack with the supercapacitor consistently exceeds that of the stack without the supercapacitor by approximately 0.125 V, mitigating the impact of rapid load changes. The results verify the feasibility of the proposed air-cooled PEMFC-powered USV.

Pseudo‐ductility behavior of carbon/glass hybrid composites with unidirectionally arrayed chopped strands: Experimental and numerical research

AbstractAlthough lightweight fiber‐reinforced polymer (FRP) composites are widely used in various engineering fields due to their high specific strength and modulus, the mutual exclusion of strength and toughness is one of the bottlenecks in the field of FRP design because of the inherent brittleness of fiber themselves. In this research, discontinuous fiber structures with vertical and bi‐angled slits are introduced into the thin‐ply carbon fiber prepreg. The fracture energy and delamination degree of the center carbon fiber layer could be controlled by adjusting the structural parameters to design the pseudo‐ductility of carbon/glass (C/G) hybrid laminates and obtain the higher pseudo‐yield stress. The hybrid specimens with 20 mm slits exhibit obvious pseudo‐ductility, and the pseudo‐ductility strain increases as the C/G ratio increases, while the plateau stress decreases. The larger slit distance provides sufficient propagation space for the delamination damage, which dissipates tensile energy and results in a smoother plateau area of the stress–strain curve. The stress–strain curve of the specimen with a smaller slit exhibits a noticeable rapid load decrease caused by the transient propagation of delamination damage. The peak stress of hybrid laminate with bi‐angled slits shows the highest pseudo‐yield stress. The present finite element model successfully analyzed the pseudo‐ductile damage propagation of C/G hybrid laminates with vertical slits, and the results are in good agreement with the experiments.Highlights Revealed the pseudo‐ductility behavior of carbon/glass hybrid composites. The pseudo‐ductility of carbon/glass hybrid composites is controllable. The pseudo‐ductility strain increases with the increase of C/G ratio.

Research Progress on the Dynamic Characteristics of Circulating Fluidized Bed Boilers While Processing Rapid Variable Loads

Research Progress on the Dynamic Characteristics of Circulating Fluidized Bed Boilers While Processing Rapid Variable Loads

Определение параметров реологической модели по данным лабораторных исследований

Different types of models are used to study the stress-strain behavior of asphalt concrete mixture during compaction. For modeling it is necessary to know the values of model parameters in the whole range of changes in the characteristics of the compacted material. The aim of the paper is to develop a methodology for determining model parameters based on the results of laboratory creep-recovery testing of asphalt-concrete mixture. In the paper, a model reflecting elastic, visco-elastic and visco-fluid properties of the compacted material is adopted. A differential equation representing the law of behavior of the asphalt-concrete mixture layer under load is obtained. The stages of creep-recovery testing are analytically described, namely: rapid loading with a constant load and deformation under this load; load removal and recovery. Initial conditions for the mentioned stages are determined. Taking into account the initial conditions, analytical expressions of the laws of deformation of the model under the action of a constant load and in the process of recovery are obtained. The methodology of laboratory experiments on creep-recovery is described, according to the results of which the required values of the model parameters with minimum absolute error are obtained. The developed methodology allows to determine the parameters of the model describing the stress-strain behavior of asphalt-concrete mixture of different density and temperature. Consequently, it is possible to simulate the behavior of the asphalt concrete mixture layer at the preliminary, main and final stages of compaction in order to determine the effective operating modes of compaction equipment.

Electro-hydraulic SBW fault diagnosis method based on novel 1DCNN-LSTM with attention mechanisms and transfer learning

The Electro-hydraulic Steer-by-Wire (EH-SBW) is the future trend of commercial vehicle steering systems due to their dual actuator redundancy. The accurate fault diagnosis of the EH-SBW is an important basis for ensuring the safety of commercial vehicles. However, due to the strong coupling between dual actuators, rapid load changes and difficult sampling lead to the difficulty of existing techniques to meet the fault diagnosis of EH-SBW. Therefore, we propose the EH-SBW fault diagnosis method based on novel 1DCNN-LSTM with attention mechanisms and transfer learning, which contains a fault type diagnosis neural network (FTDNN) model and a fault degree estimation neural network (FDENN) model. The steering feature extractor (SFE) in the FDENN model fuses the driver’s long time-domain driving trend signals and the short time-domain signals from the steering system to extract the feature map, so that the feature map have more valid information in the case of fast load changes. Based on the result of the FTDNN and the feature map, the scaling attention layer in the FDENN amplifies the features that are favourable to the fault degree estimation accuracy and suppresses the expression of unfavourable features, which reduces the impact of strong coupling relationships on the fault degree estimation accuracy. The dynamic sample allocation strategy performs transfer learning of the SFE and scaling attention layer through a small number of samples, which enables the FDENN model to effectively estimate the degree of failure of the hydraulic mechanism. The experimental results show that the diagnostic accuracy of the proposed method is 94% when the electric mechanism fails. The diagnostic accuracy of the proposed method is 92% when the hydraulic mechanism fails.