A higher-order beam model for the snap-buckling analysis of FG pipes conveying fluid

Hao-Xuan Ding,Gui-Lin She 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.1

The snap buckling of the FG curved pipes conveying fluid has not been reported due to the existing research on the snap-buckling problem. Therefore, the purpose of this paper is to explore this issue. First, we adopt a new high-order shear theory model and consider the thermal and geometric nonlinearity effects, and assume that the density and modulus of elasticity of the liquid are independent of temperature. Based on the generalized variational principle, the governing equation of the FG curved pipes conveying fluid is derived. Then, we assume that the FG curved pipes conveying fluid has simply supported boundary or fixed supported boundary conditions, and use the two step perturbation method to obtain the expression of the relationship between load and deflection. Then, we investigate the influence of boundary conditions, shear deformation, temperature variation, functional gradient index parameters, liquid flow velocity and geometry size on the snap buckling problems of the FG curved pipes conveying fluid. The results show that these factors have significant influence on the fluidstructure interaction problems.

Wave propagation in a FG circular plate via the physical neutral surface concept

Gui-Lin She,Hao-Xuan Ding,Yi-Wen Zhang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.2

In this paper, the physical neutral surface concept is applied to study the wave propagation of functionally graded (FG) circular plate, the wave equation is derived by Hamiltonian variational principle and the first-order shear deformation plate model. Then, we convert the equations to dimensionless equations. The exact solution of wave propagation problem is obtained by Laplace integral transformation, the first order Hankel integral transformation and the zero order Hankel integral transformation. The results obtained by the current model are very close to those obtained in the existing literature, which indicates the correctness and reliability of this study. Moreover, the effects of the functionally graded index parameters and pore volume fraction on the wave propagation are also discussed in detail.

Development and validation of FRAT code for coated particle fuel failure analysis

Li Jian,She Ding,Shi Lei,Sun Jun 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

TRISO-coated particle fuel is widely used in high temperature gas cooled reactors and other advanced reactors. The performance of coated fuel particle is one of the fundamental bases of reactor safety. The failure probability of coated fuel particle should be evaluated and determined through suitable fuel performance models and methods during normal and accident condition. In order to better facilitate the design of coated particle fuel, a new TRISO fuel performance code named FRAT (Fission product Release Analysis Tool) was developed. FRAT is designed to calculate internal gas pressure, mechanical stress and failure probability of a coated fuel particle. In this paper, FRAT was introduced and benchmarked against IAEA CRP-6 benchmark cases for coated particle failure analysis. FRAT's results agree well with benchmark values, showing the correctness and satisfactory applicability. This work helps to provide a foundation for the credible application of FRAT.

Implementation of functional expansion tally method and order selection strategy in Monte Carlo code RMC

Wang, Zhenyu,Liu, Shichang,She, Ding,Su, Yang,Chen, Yixue Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.2

The spatial distribution of neutron flux or reaction rate was calculated by cell or mesh tally in traditional Monte Carlo simulation. However, either cell or mesh tally leads to the increase of memory consumption and simulation time. In this paper, the function expansion tally (FET) method was developed in Reactor Monte Carlo code RMC to solve this problem. The FET method was applied to the tallies of neutron flux distributions of uranium block and PWR fuel rod models. Legendre polynomials were used in the axial direction, while Zernike polynomials were used in the radial direction. The results of flux, calculation time and memory consumption of different expansion orders were investigated, and compared with the mesh tally. Results showed that the continuous distribution of flux can be obtained by FET method. The flux distributions were consistent with that of mesh tally, while the memory consumption and simulation time can be effectively reduced. Finally, the convergence analysis of coefficients of polynomials were performed, and the selection strategy of FET order was proposed based on the statistics uncertainty of the coefficients. The proposed method can help to determine the order of FET, which was meaningful for the efficiency and accuracy of FET method.

Wave propagation in spherical and cylindrical panels reinforced with carbon nanotubes

Yi-Wen Zhang,Hao-Xuan Ding,Gui-Lin She 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.1

Based on the third-order shear deformation theory, the wave propagations in doubly curved spherical- and cylindrical- panels reinforced by carbon nanotubes (CNTs) are firstly investigated in present work. The coupled equations of wave propagation for the carbon nanotubes reinforced composite (CNTRC) doubly curved panels are established. Then, combined with the harmonic balance method, the eigenvalue technique is adopted to simulate the velocity-wave number curves of the CNTRC doubly curved panels. In the end, numerical results are showed to discuss the effects of the impact of key parameters including the volume fraction, different shell types (including spherical (R1=R2=R) and cylindrical (R1=R, R2=→∞)), wave number as well as modal number on the sensitivity of elastic waves propagating in CNTRC doubly curved shells.

Conceptual design study on Plutonium-238 production in a multi-purpose high flux reactor

Li Jian,Zhao Jing,Liu Zhihong,She Ding,Xie Heng,Shi Lei 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Plutonium-238 has always been considered as the one of the promising radioisotopes for space nuclear power supply, which has long half-life, low radiation protection level, high power density, and stable fuel form at high temperatures. The industrial-scale production of 238Pu mainly depends on irradiating solid 237NpO2 target in high flux reactors, however the production process faces problems such as large fission loss and high requirements for product quality control. In this paper, a conceptual design study of producing 238Pu in a multipurpose high flux reactor was evaluated and analyzed, which includes a sensitivity analysis on 238Pu production and a further study on the irradiation scheme. It demonstrated that the target structure and its location in the reactor, as well as the operation scheme has an impact on 238Pu amount and product quality. Furthermore, the production efficiency could be improved by optimizing target material concentration, target locations in the core and reflector. This work provides technical support for irradiation production of 238Pu in high flux reactors.

An optimization design study of producing transuranic nuclides in high flux reactor

Xu Wei,Li Jian,Zhao Jing,She Ding,Liu Zhihong,Xie Heng,Shi Lei 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.8

Transuranic nuclides (such as 238Pu, 252Cf, 249Bk, etc.) have a wide range of application in industry, medicine, agriculture, and other fields. However, due to the complex conversion chain and remarkable fission losses in the process of transuranic nuclides production, the generation amounts are extremely low. High flux reactor with high neutron flux and flexible irradiation channels, is regarded as the promising candidate for producing transuranic nuclides. It is of great significance to increase the conversion ratio of transuranic nuclides, resulting in higher efficiency and better economy. In this paper, we perform an optimization design evaluation of producing transuranic nuclides in high flux reactor, which includes optimization design of irradiation target and influence study of reactor core loading. It is demonstrated that the production rate increases with appropriately determined target material and target structure. The target loading scheme in the irradiation channel also has a significant influence on the production of transuranic nuclides