scholarly journals Design Optimization and Fatigue Analysis for Seal Joint of Control Rod Drive Mechanism

2018 ◽  
Vol 165 ◽  
pp. 22014
Author(s):  
Shao Xuejiao ◽  
Dujuan

Two kinds of seal joint thickness of control rod drive mechanism seal house were analyzed on stress and fatigue by using finite element method, and it provides analytical basis for equipment optimization, design manufacturing and problem handing. In the fatigue computing, all the transients were grouped into several groups, so as to separate the transients not at the same stage obviously. Meanwhile, the transients can be respectively combined in every group to reduce the redundant conservatism of computation. The elastoplastic strain correction factor was modified by analyzing thermal and mechanical load separately referring the rules of RCC-M 2002.By comparing the stress of two thickness joints, the results are found that the fatigue results of the thinner thickness are safer, but this is contrary to the rule of other results. The fatigue usage factor can be reduced by using modified elastoplastic strain correction factor when the amplify of the primary and secondary stress is large produced by both thermal load and mechanical load.

2012 ◽  
Vol 229-231 ◽  
pp. 613-616
Author(s):  
Yan Jue Gong ◽  
Yuan Yuan Zhang ◽  
Fu Zhao ◽  
Hui Yu Xiang ◽  
Chun Ling Meng ◽  
...  

As an important part of the vertical axis wind turbine, the support structure should have high strength and stiffness. This article adopts finite element method to model a kind of tower structure of the vertical axis wind turbine and carry out static and modal analysis. The static and dynamic characteristic results of tower in this paper provide reference for optimization design the support structure of wind turbine further.


2015 ◽  
Vol 07 (06) ◽  
pp. 1550085 ◽  
Author(s):  
Z. C. He ◽  
G. Y. Zhang ◽  
L. Deng ◽  
Eric Li ◽  
G. R. Liu

The node-based smoothed finite element method (NS-FEM) proposed recently has shown very good properties in solid mechanics, such as providing much better gradient solutions. In this paper, the topology optimization design of the continuum structures under static load is formulated on the basis of NS-FEM. As the node-based smoothing domain is the sub-unit of assembling stiffness matrix in the NS-FEM, the relative density of node-based smoothing domains serves as design variables. In this formulation, the compliance minimization is considered as an objective function, and the topology optimization model is developed using the solid isotropic material with penalization (SIMP) interpolation scheme. The topology optimization problem is then solved by the optimality criteria (OC) method. Finally, the feasibility and efficiency of the proposed method are illustrated with both 2D and 3D examples that are widely used in the topology optimization design.


2009 ◽  
Vol 149 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Meiling Zhu ◽  
Paul Kirby ◽  
Martin Wacklerle ◽  
Markus Herz ◽  
Martin Richter

Author(s):  
Zhao Yin ◽  
Hangduo Gao ◽  
Gao Lin

Based on the two-dimensional (2D) elastic theory without enforcing any beam assumption, an efficient semi-analytical scaled boundary finite element method (SBFEM) is proposed to solve the bending and free vibration responses of composite laminated and sandwich beams under the mechanical load. The scaled center is placed at infinity, which produces the accurate result by discretizing only the longitudinal direction of the beam structure treated as a one-dimensional (1D) discretization problem. A new kind of 1D high-order spectral element shape functions with the advantages of high accuracy and superior convergence is introduced in SBFEM coordinate system to approximate the geometric model and corresponding variables. The principle of weighted residual in conjunction with the Green’s theorem are applied to obtain the SBFEM governing equation of each layer with respect to radial displacement fields. The solution of equation is indicated analytically by a matrix exponential function, which can be accurately solved by using the precise integration technique (PIT). Finally, an effective and simple stiffness matrix is obtained. By comparing two examples with the solutions based on the finite element method (FEM), the results show that the proposed method has good accuracy and rapid convergence with only a few meshes. The numerical examples are given to investigate the parametric effects of the stacking sequence, thickness ratio, boundary condition, and load form on the variation of the displacement, stress and natural frequency. The results validate that the present technique is also applicable to the complex beam structure with softcore layer inside.


2011 ◽  
Vol 130-134 ◽  
pp. 672-676 ◽  
Author(s):  
Gui Chuan Hu ◽  
Jing Hua Liu

The important sign of product innovation is the superior to exploit better manufacture functions, light weight as well as reliable performances with lower cost. The paper is focused on the truss structure optimized design which is used for arch bridge reinforcement. The strength, stiffness and dynamics consideration are analyzed by finite element method (FEM), and the topology optimized truss structure is put forward based on the analyzed results.


2015 ◽  
Vol 06 (03) ◽  
pp. 1550007
Author(s):  
Sung-Jun Lee ◽  
Sang-Hwan Lee ◽  
Yoon-Suk Chang

The head penetration nozzle of control rod driving mechanism (CRDM) is known to be susceptible to primary water stress corrosion cracking (PWSCC) due to the welding-induced residual stress. Especially, the J-groove dissimilar metal weld regions have received many attentions in the previous studies. However, even though several advanced techniques such as weight function and finite element alternating methods have been introduced to predict the occurrence of PWSCC, there are still difficulties in respect of applicability and efficiency. In this study, the extended finite element method (XFEM), which allows convenient crack element modeling by enriching degree of freedom (DOF) with special displacement function, was employed to evaluate structural integrity of the CRDM head penetration nozzle. The resulting stress intensity factors of surface cracks were verified for the reliability of proposed method through the comparison with those suggested in the American Society of Mechanical Engineering (ASME) code. The detailed results from the FE analyses are fully discussed in the manuscript.


2012 ◽  
Vol 466-467 ◽  
pp. 1000-1005 ◽  
Author(s):  
Yan Li ◽  
Jun Bin Cao ◽  
Xiao Lei Li

In order to study the effect of patch shape on the strength of the damaged skin after rivet repair, the paper uses the elastic-plastic finite element method to analyze the rivet repair of the circular hole damage and gives the rivet loads of all the rivets under the three shapes of patches respectively. The results show that the circular patch can observably improve the strength of the aircraft skin after rivet repair, compared with the right-angled rectangle patch and the fillet-rectangle patch, in the same condition of the patch materials and rivet parameters and technology equipments. The design can enhance the security of the repaired aircraft and have some values for the peacetime repair and the emergent repair of aircraft structure.


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