Fault severity describes the level of impact caused by a fault. In the event of a malfunction in a nuclear power plant, a vast amount of data and alarms are generated, making it challenging for operators to identify a...
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Predicting fuel behavior in the reactor is a typical multiphysics coupling problem. The traditional fuel performance analysis adopts a decoupling way. To provide a higher fidelity tool for fuel performance simulation,...
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Since the NRC issued the PSA policy in 1995, PSA containing risk information has been widely used in supervision and design. Subsequently, the concept of "risk-informed" has gained more and more recognition,...
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Pump equipment is the main source of vibration and noise during ship operation, and there are distinct characteristic line spectra at various transmission paths, which is not conducive to vibration reduction and noise...
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Prognostics and Health Management (PHM) is currently the mainstream solution for the condition monitoring and maintenance of industrial systems. In PHM, the system condition is monitored by monitoring the operational ...
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In recent years, with the continuous expansion of unmanned aerial vehicle (UAV) swarm applications and the rapid development of the UAV self-organizing network system, the related security threats have also increased....
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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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A finite-strain homogenization creep model for composite fuels under irradiation conditions is developed and verified,with the irradiation creep strains of the fuel particles and matrix correlated to the macroscale cr...
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A finite-strain homogenization creep model for composite fuels under irradiation conditions is developed and verified,with the irradiation creep strains of the fuel particles and matrix correlated to the macroscale creep responses,excluding the contributions of volumetric strain induced by the irradiation swelling deformations of fuel particles.A finite element(FE)modeling method for uniaxial tensile creep tests is established with the irradiation effects of nuclear materials taken into *** proposed models and simulation strategy are numerically implemented to a kind of composite nuclear fuel,and the predicted mesoscale creep behaviors and the macroscale creep responses are *** research results indicate that:(1)the macroscale creep responses and the mesoscale stress and strain fields are all greatly affected by the irradiation swelling of fuel particles,owing to the strengthened mechanical interactions between the fuel particles and the matrix.(2)The effective creep rates for a certain case are approximately two constants before and after the critical fission density,which results from the accelerated fission gas swelling after fuel grain recrystallization,and the effects of macroscale tensile stress will be more enhanced at higher temperatures.(3)The macroscale creep contributions from the fuel particles and matrix depend mainly on the current volume fractions varying with fission density.(4)As a function of the macroscale stress,temperature,initial particle volume fraction and particle fission rate,a multi-variable mathematical model for effective creep rates is fitted out for the considered composite fuels,which matches well with the FE *** study supplies important theoretical models and research methods for the multi-scale creep behaviors of various composite fuels and provides a basis for simulation of the thermal–mechanical behavior in related composite fuel elements and assemblies.
Models to describe the damage and fracture behaviors of the interface between the fuel foil and cladding in UMo/Zr monolithic fuel plates were established and numerically *** effects of the interfacial cohesive streng...
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Models to describe the damage and fracture behaviors of the interface between the fuel foil and cladding in UMo/Zr monolithic fuel plates were established and numerically *** effects of the interfacial cohesive strength and cohesive energy on the irradiationinduced thermal-mechanical behaviors of fuel plates were *** results indicated that for heterogeneously irradiated fuel plates:(1)interfacial damage and failure were predicted to be initiated near the fuel foil corner with higher fission densities,accompanied by the formation of a large gap after interface failure,which was consistent with some experimental observations;high tensile stresses in the fuel foil occurred near the edges of the failed interface,attributed to through-thickness cracking of the fuel foil,as found in some post-irradiation examinations;(2)the cohesive strength and cohesive energy of the interface both influenced the in-pile evolution behaviors of fuel plates;a lower cohesive strength or cohesive energy resulted in faster interfacial damage;(3)after interface fracture,the thickness of the whole plate increased to a greater degree(by~20%)than that of the samples without interfacial damage,which was attributed to the locally enhanced Mises stresses and the nearby creep deformations around the cracked *** study provided a theoretical basis for assessing failure in fuel elements.
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.
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