A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed *** method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments ...
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A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed *** method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer,and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite ***∅520 mm composite cases as a case study,the filament-winding-process-induced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental *** numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa,*** values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 ***,the predicted damage locations,situated respectively in the dome and cylinder,agree well with the experimental *** observations indicate that use of flexible component reduces the load-bearing capacity of the ***,it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.
Aiming at the problem of small output torque in the design process of traveling to wave ultrasonic motor, this paper proposes a method of optimizing the output torque of traveling to wave ultrasonic motor based on mul...
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The control rod drive mechanism (CRDM) is a critical device in nuclear plants. This paper proposes a kind of CRDM applying the cylindrical linear induction motor (CLIM). First, the structure and the working principle ...
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The control rod drive mechanism (CRDM) is a kind of servo mechanism for the reactor control system of the nuclear power plant. This paper presents a cylindrical linear induction motor suitable for the CRDM. First, the...
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The Electro-Hydrostatic Actuator(EHA)is a typical hydro-mechatronic control *** to the limited accuracy of measurement,inadequate knowledge,and vague judgments,hybrid uncertainties,including aleatory and epistemic unc...
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The Electro-Hydrostatic Actuator(EHA)is a typical hydro-mechatronic control *** to the limited accuracy of measurement,inadequate knowledge,and vague judgments,hybrid uncertainties,including aleatory and epistemic uncertainties,inevitably exist in the performance assessment of EHA *** methods ignored the hybrid uncertainties which can hardly obtain a satisfactory result while wasting a lot of time on the experimental *** overcome this drawback,a metamodeling method for hybrid uncertainty propagation of EHA systems is developed via an active learning Gaussian Process(GP)*** proposed method is bifurcated into three pillars:(A)Initializing the GP model and generating the optimum candidate sampling set by an Optimized Max-Minimize Distance(OMMD)algorithm,which aims to maximize the minimum distance between the added samples and original samples,(B)maximizing the learning function and generating new samples by a developed farthest or nearest judgment strategy,while updating the original GP model,and(C)judging the convergence by three uncertainty metrics,i.e.,the area metric,maximum variance metric,and the mean value metric.A numerical example is exemplified to evaluate the effectiveness and efficiency of the proposed ***,the EHA system of aircrafts is examined to show the application of the proposed method for high-dimensional *** effects of the uncertainties in the Proportional-Integral-Differential(PID)of the EHA system are also examined.
Small modular reactor (ACP100), as a key scientific and technological project of third-generation nuclear power technology of China National Nuclear Corporation, must achieve the purpose of eliminating large-scale rad...
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In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial tempera...
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In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature(T=300-400 K),initial pressure(P=0.1-0.3 MPa),turbulence intensity(u'=1.0-2.7 m/s),oxygen volumetric percentage(φ(O_(2))=15%-21%)and carbon dioxide volumetric percentage(φ(CO_(2))=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale(D6-D8)disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.
Vision-based intrusion detection tasks have extensive applications in crucial fields such as automatic driving, intelligent security, and monitoring. Previous vision-based intrusion detection methods have mainly focus...
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Vision-based intrusion detection tasks have extensive applications in crucial fields such as automatic driving, intelligent security, and monitoring. Previous vision-based intrusion detection methods have mainly focused on whether pedestrians intrude on a restricted Area-of-Interest (AoI) from a static or dynamic view. However, in real-world scenarios, intrusion detection tasks often involve a variety of intrusion categories and encounter some challenging environments, beyond just pedestrians in a normal environment. Therefore, exploring related tasks of dynamicview multi-domain multi-category intrusion detection (namely MM-ID) is important and valuable but remains unexplored. In this work, we propose a comprehensive benchmark to address the aforementioned intrusion detection tasks, including multiple datasets, reasonable metrics, End-to-End framework design, and extensive evaluations. First, we develop five publicly available datasets, namely, Normal-Cityintrusion-Multicategory (NormalCMC), Foggy-Cityintrusion-Multicategory (Foggy-CMC), RainyCityintrusion-Multicategory (Rainy-CMC), Night-CityintrusionMulticategory (Night-CMC), and BDD-intrusion, conduct statistical analysis on these datasets and design three evaluation metrics. Then, an efficient End-to-End framework (MMID-YOLO) is proposed for the MM-ID task, with two effective improvements: (1) We propose a new unsupervised domain adaptation algorithm (namely, I-DANN) to conduct important feature alignment between the Source domain and Target domain. (2) We propose a diffusion model-based data augmentation method to improve the generalization of the model to unknown environments. Further, we design and propose three training schemes to conduct comprehensive experiments and comparisons, which can also serve as strong baselines for our MM-ID task: the Combined model, the End-to-End model, and the Domain Adaption model, respectively. The experimental results show that our MMIDYOLO can perform much better than other
The heterogeneous fleet vehicle routing problem (HFVRP) is of great significance in logistics and transportation. This paper considers a crucial and challenging HFVRP variant, namely multi-objective fleet size and mix...
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To efficiently decrease ablation heat accumulation and improve the ability of ZrC-SiC/TaC coatings to protect carbon/carbon(C/C)composites,a thermally conductive nanonetwork with a ceramic@carbon core-shell structure ...
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To efficiently decrease ablation heat accumulation and improve the ability of ZrC-SiC/TaC coatings to protect carbon/carbon(C/C)composites,a thermally conductive nanonetwork with a ceramic@carbon core-shell structure was designed and ***-derived SiC/TaC with a graphene carbon shell was synthesized and introduced into a ZrC coating by supersonic atmospheric plasma spraying(SAPS).Graphene shell paths increased the heat transfer capability by lowering the surface temperature to approximately 200℃during oxyacetylene *** heat dissipation of the graphene shell in the ZrC-SiC/TaC@C coating reduced the volatilization of low-melting-point phases and delayed the sintering of ZrO_(2) ***,the graphene shell in ZrC-SiC/TaC@C coating decreased the mass and linear ablation rates by 91.4%and 93.7%compared to ZrC-SiC/TaC coating,*** work provided a constructive idea for improving the ablation resistance of the coatings by incorporating carbon nanomaterials as a function of heat dissipation.
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