Study on 2.5D C/C composite finger seal integrate optimization combined with microstructural parameters of material and macro geometry of finger seal

2015 ◽  
Vol 231 (9) ◽  
pp. 1599-1608 ◽  
Author(s):  
Hua Su ◽  
Lu Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Contact Pressure ◽  
Optimization Method ◽  
Nsga Ii ◽  
Microstructural Parameters ◽  
Multi Objective Genetic Algorithm ◽  
Design Variables ◽  
Element Method

The current study focuses on performance analysis and structural optimization of the 2.5 D C/C composite finger seal. A micro/macrostructural integrated optimization method of 2.5D C/C composite finger seal is presented. Based on uniform strain assumption the stiffness average method is used to predict the elastic properties of 2.5D C/C composite material. In order to achieve the advantage of the designability of composite material, the microstructure parameters are also as design variables together with the macro structure of finger seal. Considering the two optimization objectives, leakage and contact pressure, are both implicit functions of the structure parameters of finger seal which obtained by finite element method, a Krige model is established to replace the finite element method analysis in each optimization iteration, which could improve the optimization calculating efficiency obviously. By using the multi objective genetic algorithm NSGA-II the 2.5D C/C composite finger seal optimization is implemented availably. An example is given which indicates the leakage and contact pressure of finger seal decrease significantly through the integration optimization of 2.5D C/C composite finger seal which develop a new approach to design finger seal with high performances.

Topology Optimization Using Node-Based Smoothed Finite Element Method

2015 ◽  
Vol 07 (06) ◽  
pp. 1550085 ◽  
Author(s):  
Z. C. He ◽  
G. Y. Zhang ◽  
L. Deng ◽  
Eric Li ◽  
G. R. Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Optimization Design ◽  
Solid Mechanics ◽  
Optimality Criteria ◽  
Topology Optimization Problem ◽  
Design Variables ◽  
Smoothed Finite Element Method ◽  
Element Method

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.

Shape Opimization of Femoral Components of an Artificial Hip Prosthesis Using the Three-Dimensional P-Version Finite Element Method

2001 ◽  
Author(s):  
Masaru Higa ◽  
Ikuya Nishimura ◽  
Hiromasa Tanino ◽  
Yoshinori Mitamura
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hip Prosthesis ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Peak Stress ◽  
Cross Sectional ◽  
Design Variables ◽  
Dimensional Shape ◽  
Element Method

Abstract The three-dimensional shape optimization of cemented total hip arthroplasty (THA) was introduced in this paper. The P-version Finite Element Method (FEM) combined with an optimization procedure was used to minimize the peak stress in the bone cement near the tip of the implant. Six-design variables were used in this study. Each variable represents the dimension of the medial-lateral width and anterior-posterior width of the three levels (proximal, distal and middle) of cross sectional area of the prosthesis. The results of the design optimization showed considerable reduction in stress concentration compared to the initial design that is currently used clinically.

Effect of Traffic Flow on Characteristics of Piezoelectric Harvesting Unit

2014 ◽  
Vol 672-674 ◽  
pp. 902-905 ◽  
Author(s):  
Chun Hua Sun ◽  
Guang Qing Shang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Power ◽  
Traffic Flow ◽  
Contact Pressure ◽  
Green Energy ◽  
The Finite Element Method ◽  
Oil Resources ◽  
Element Method

To protect dwindling coal and oil resources and open up a new way of renewable green energy, the technology of piezoelectric harvesting from pavement is proposed. Effect of traffic flow, including contact pressure and speed of a vehicle, on characteristics of a piezoelectric harvesting unit is discussed with the finite element method. Results show that the harvested electric power is approximately linear with the contact pressure and a vehicle’s speed. The contact pressure takes more effect on the harvested electric power and stress on pavement than the vehicle’s speed. A PHU of 280*280*20mm can harvest about 10mJ electric power when the contact pressure is 0.85MPa. That shows that application of the piezoelectric harvesting unit has very nice optimistic prospects.

Determination of the auxiliary anode position via finite element method in impressed current cathodic protection

2019 ◽  
Vol 66 (4) ◽  
pp. 432-438
Author(s):  
Yingwei Liu ◽  
Zhongwu Zhang ◽  
Yang Zhang ◽  
Jianneng Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cathodic Protection ◽  
Measurement Errors ◽  
Optimization Method ◽  
Content Type ◽  
Protection Method ◽  
Impressed Current ◽  
Impressed Current Cathodic Protection ◽  
Element Method

Purpose It is a challenge in the design to determine the feasible anode position and the supply current when the hull is protected by the impressed current cathodic protection method. It is difficult to obtain these parameters through traditional experimental methods due to the huge hull surface area and geometric complexity. This study aims to solve the problem by finite element method. Design/methodology/approach First, a great number of experiments need to be conducted; second, experiments are empirical; finally, there exist measurement errors, etc. All these factors make the experimental results less reliable. The application of the finite element method, combined with other technologies, is expected to overcome these deficiencies. In this paper, the combined Matlab and Comsol method was used to calculate various anode positions and corresponding protection areas with a series of input current conditions. The calculation is implemented via the script in Matlab. Findings As a result, the best design can be obtained. The results show that the method provided in this paper can replace the experiment to a certain extent, save human and material resources and reduce the design time. The method also can be applied to other similar fields, having a good universality. Originality/value This optimization method can be extended to other areas of relevant production and research, having a good universality.

Analysis and Optimization of Metal to Composite Joints for Marine Structures

2014 ◽  
Vol 556-562 ◽  
pp. 91-95
Author(s):  
Xiao Wen Li ◽  
Ping Li ◽  
Zhuang Lin ◽  
Dong Mei Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Performance ◽  
Optimization Method ◽  
Additional Stress ◽  
Marine Structures ◽  
Hybrid Joint ◽  
Composite Joint ◽  
Numerical Predictions ◽  
Element Method

Composite to metal joints as important components of marine structures are gradually found in the marine industry. The purpose of this study is to investigate mechanical performance and optimization method of the composite sandwich to steel joints. The main emphasis was placed on the mechanical properties of a hybrid joint between a sandwich glass fibre reinforced plastic superstructure and a steel main hull. Based on the experiments of a base joint, a new finite element method was used to analyze a series of joints. The optimized joint was presented due to reducing weight and enhancing the mechanical performance. The numerical predictions of the base hybrid joint showed a very good correlation with the experiment results, which validated the reliability of the new finite element method. The strength of the optimized joint was also evaluated by finite element method. The result is similar to the base joint. And there is no additional stress concentration in weak parts. The optimized joint has 30% lower weight than the base joint, and the stress is only about 5% ~ 56% of the base one. The results of the present work imply that the change of geometric parameter is an effective method to improve the performance of the metal to composite joint.

Performance Evaluation of Spring for the Vehicle Suspension System Using the Nonlinear Finite Element Method

2014 ◽  
Vol 635-637 ◽  
pp. 594-597
Author(s):  
Byeong Soo Kim ◽  
Byung Young Moon ◽  
Sung Kwan Kim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Material ◽  
Suspension System ◽  
Nonlinear Finite Element ◽  
Nonlinear Finite Element Method ◽  
Air Spring ◽  
Rubber Sleeve ◽  
The Impact ◽  
Element Method

Air spring is used for the suspension system and it affects the vehicle stability and riding comfort by improving the impact-relief, braking, and cornering performance. Air Spring is comprised of the upper plate, lower plate, and rubber sleeve. Rubber sleeve is the composite material, which is made up of combination of rubber and Nylon, and the characteristics are changed according to the shape of rubber-sleeve, the angle of reinforcement cord. In this study, the distribution of internal stresses and the deformation of rubber composite material are analyzed through the nonlinear finite element method. The result showed that the internal maximum stresses and deformations about the changes of cord angle caused the more the Young's modulus decrease, the more maximum stress reduced.

Influence of Acetabular Liner Design on Periprosthetic Pressures during Daily Activities

2014 ◽  
Vol 601 ◽  
pp. 159-162
Author(s):  
Mircea Krepelka ◽  
Mirela Toth-Taşcău
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Pressure ◽  
Design Parameters ◽  
Acetabular Liner ◽  
Hip Prostheses ◽  
Small Influence ◽  
The Difference ◽  
Contact Pressures ◽  
Element Method

In this study, periacetabular pressures produced by different acetabular liner geometries were analyzed using Finite Element Method. The cup models consist of hemispherical metal shells fitted with normal and different chamfered polyethylene liner geometries, with the same degree of femoral head coverage. The aim of this study was to understand the influence of the design parameters of the chamfered liners, which are primarily designed to increase the range of motion (ROM) of the hip joint and reduce the risk of impingement, on the acetabular contact pressures. The cup models were loaded to simulate periacetabular pressures during routine activities. The proposed models have been analyzed considering a cup position of 40olateral abduction and 15oanteversion. The results show that the difference in contact pressure between the normal and chamfer models was not substantial in the given orientation of the cup. Also, the increase of the chamfer angle has a small influence on the maximum contact pressures, although that could be also dependent on the reduction of the polyethylene thickness. Pre-clinical testing of total hip prostheses using Finite Element Method enables the evaluation of contact pressures and stress distribution, and proves to be a valuable tool to analyze the parameters reducing the contact pressure.

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