In this study, tensile test and Charpy impact test of domestic A508-III steel are carried out in the ductile-brittle transition range, in which obtained the mechanical properties and temperature dependence of Charpy i...
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In this study, tensile test and Charpy impact test of domestic A508-III steel are carried out in the ductile-brittle transition range, in which obtained the mechanical properties and temperature dependence of Charpy impact energy. Fracture toughness test temperature is determined through the correlation with characteristic temperature, at which Charpy impact energy is 28 J or 41 J. The Master Curve of 12.7 mm SE(B) is respectively from the single-temperature and multi-temperature method, and measured T0 was valid. The result shows that the reference temperature T0 derived from two methodsis basically consistent. And the reference temperature T0 of domestic A508-III steel is about -63°C.
In order to verify the correctness of PLC programs by formal methods, the definition of denotational semantics on PLC program language was studied to achieve PLC programs modeling and model checking. Based on the exte...
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In order to verify the correctness of PLC programs by formal methods, the definition of denotational semantics on PLC program language was studied to achieve PLC programs modeling and model checking. Based on the extended λ-calculus definition, the configuration of PLC program architecture, denotational semantics of PLC programs and functions of denotational semantics were defined, which proves the basis of model checking and theorem.
Based on finite element method (FEM), dynamic model of tiltrotor with universal joint hub and advanced geometry blades is established. Modes of the free-free blades and the rotor are analyzed, and modes measurement of...
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Based on finite element method (FEM), dynamic model of tiltrotor with universal joint hub and advanced geometry blades is established. Modes of the free-free blades and the rotor are analyzed, and modes measurement of the blades and the rotor is accomplished with LMS system by combining local coordinates with global ones. Results of mode identification in experiment are compared with calculation results. Availability and rationality are verified between experimental procedure and analytical method. The comparation shows that the established model has a great practicability and a good ability to analyze natural characteristic of tiltrotor with universal joint hub.
The design and test of the smart rotor model with active trailing edge flap is performed based on a push-pull double X-frame piezoelectric actuator. The static displacements of piezoelectric stacks and actuators are m...
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The design and test of the smart rotor model with active trailing edge flap is performed based on a push-pull double X-frame piezoelectric actuator. The static displacements of piezoelectric stacks and actuators are measured. Unload test is used to verify the performance of the actuator and the load test is conducted to demonstrate whether the actuator can drive the flap with hinge moment in hover. The deflection of the trailing edge flaps are measured by using linear Hall sensors in different actuation frequencies and voltages. Test result agrees with the analysis and shows that the piezoelectric actuators can actuate the flaps and the method is practicable and feasible.
The determination of crack-opening-area (COA) is very important in the application of LBB technique. A numerical method based on coupled finite element-meshless Galerkin method (FEM/EFG) is proposed to calculate the c...
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This paper establishes a nodal method to solve the two coupled equations transformed from the transport equation by SP3 method. In the nodal method, diffusion equation is discretized into average fluxes in the nodes a...
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This paper establishes a nodal method to solve the two coupled equations transformed from the transport equation by SP3 method. In the nodal method, diffusion equation is discretized into average fluxes in the nodes and partial currents on the nodal boundaries. Nodal response relationship is obtained by expanding the detailed nodal flux into a sum of exponential functions. Numerical results demonstrates that the nodal SP3 method can treat polygonal meshes in different shapes with good parallel property, and that it can provide a similar accuracy while runs about six times faster than the nodal-SN (N=4) method DNTR under the same mesh.
We combined the subgroup method and the method of characteristics for neutron resonance self-shielding calculation, and programmed a resonance calculation code SGMOC. This code is based on the WIMSD format multi-group...
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We combined the subgroup method and the method of characteristics for neutron resonance self-shielding calculation, and programmed a resonance calculation code SGMOC. This code is based on the WIMSD format multi-group data library. The numerical results of SGMOC are in good agreement with those of MCNP, and thus SGMOC has high calculation precision and geometry flexibility. Based on the SGMOC code, we studied two modification methods for the resonance interference effect calculation. The conditional probability method had a correction effect about 30~180 pcm for kinf calculation of UO2 fuel cell. The method by virtue of NJOY code had a correction effect about 20~130 pcm for kinf calculation of UO2 fuel cell.
Based on generalized coarse mesh rebalance (GCMR) method, this paper proposes a new acceleration method for the method of characteristics (MOC) in unstructured meshes: the generalized coarse-mesh finite difference (GC...
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ISBN:
(纸本)9781617820014
Based on generalized coarse mesh rebalance (GCMR) method, this paper proposes a new acceleration method for the method of characteristics (MOC) in unstructured meshes: the generalized coarse-mesh finite difference (GCMFD) method. The GCMFD method, which applies equivalent width of coarse mesh to establish the finite difference discretization, can use unstructured coarse meshes composed of adjacent fine meshes to speed up the MOC iteration. The convergence property of the GCMFD method is controlled by width factor. However, the optimal width factor cannot be given a priori. Method of adjusting width factor automatically is proposed in this paper. Finally, the GCMFD method is adopted in the 3-D neutron transport MOC code TCM. Numerical tests show that the GCMFD, using generalized-geometry coarse meshes, can accelerate the MOC iteration with good speedup.
At present, the information and control system (I&C) and operation support system (OSS) of the nuclear power plants (NPPs) are designed separately;their structures and functions are independent. So, the compatibil...
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Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. T...
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ISBN:
(纸本)9781617820014
Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. To solve the former two parts, this paper devises an innovative stochastic evolutionary algorithm - Interval Bound Algorithm (IBA), which can optimize fuel assembly location and burnable poison placement together. IBA just uses the fuel assembly's infinite multiplication factor to get rid of unfavorable patterns and to explore new promising solution space. To solve the last part, this paper applies Estimation of Distribution Algorithms (EDAs), which also belong to evolutionary algorithms. These three parts depend on each other, so it is better not to solve them separately. In order to optimize these parts in a coupled way, we use Symbiotic Co-evolutionary Algorithm (SCA) to incorporate IBA and EDAs. This technique could reflect the real optimization process. Based on these algorithms, the corresponding LPO code of IBALPO is developed. To avoid search direction to offset for inconsistency between the LP search code and the design code, IBALPO directly adopts production core design code to evaluate LPs in a parallel computation environment. Finally, this code system is used to solve a realistic reload problem to show its performance. Obtained results have illustrated that IBALPO is efficient and robust. It can find satisfying LPs in two days using 18 CPUs after evaluating about 10000 LPs for a core containing 157 assemblies.
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