scholarly journals Linear optimal design of a magnetic repulsion negative stiffness structure

2021 ◽  
pp. 146134842199261
Author(s):  
Zhang Bao ◽  
Wang Xiaoping ◽  
Ge Xinfang
Keyword(s):  
Optimal Design ◽  
Structural Design ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Negative Stiffness ◽  
Design Parameters ◽  
Structural Parameter ◽  
Design Requirements

To reduce negative stiffness structure’s stiffness non-linearity, enhance its stability during entire working displacement range, and expand its allowable working displacement, the optimal design of negative stiffness structure based on magnetic repulsion is proposed, and its structural parameters are also provided. The new negative stiffness structure’s model is established to determine the structural design parameters. According to the change of the new negative stiffness structure’s stiffness curve, we select the structural parameter to meet the design requirements. In order to verify the effectiveness of the proposed negative stiffness structure, we carried out simulation analysis, and the results show that the optimized negative stiffness structure’s stiffness non-linearity is greatly reduced in a relatively longer displacement, and its stiffness stability is promoted substantially compared with the simple triple-magnet negative stiffness structure.

scholarly journals Optimal Design and Simulation Analysis of Spike Tooth Threshing Component Based on DEM

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1163
Author(s):  
Yajun Yu ◽  
Liangshan Li ◽  
Jiale Zhao ◽  
Xiangeng Wang ◽  
Jun Fu
Keyword(s):  
Optimal Design ◽  
Simulation Analysis ◽  
Process Analysis ◽  
Structural Parameters ◽  
Compressive Force ◽  
Microscopic Analysis ◽  
Analysis Software ◽  
Damage Rate ◽  
Tooth Type ◽  
Simulation Time

This paper takes a local drum-type corn thresher as an example. In order to make the threshing principle transform to the plate-tooth type, the width of the spike-tooth threshing component is increased gradually, and three threshing components of different shape and size are selected as the research objects. Based on the preliminary experimental research, the corn threshing process is simulation analyzed using the self-developed corn threshing process analysis software. The effects of the width of the threshing component on the corn ears threshing rate and kernel damage rate under different rates of drum rotation were studied from a macroscopic perspective. The results show that with the increase of drum rotation rate, both the corn ear threshing rate and kernel damage rate increase; with the increase of threshing component width, the threshing rate increases and the damage rate decreases; and when the component width is too large, the stacking between adjacent components has an impact on the threshing performance. The effects of threshing component width on the amount of kernel threshing and the total compressive force during the simulation time were investigated from microscopic perspective at different rates of drum rotation, and the results show that the microscopic analysis is consistent with the macroscopic analysis. Therefore, the optimization of the structural parameters and operating parameters of the threshing component was achieved. When the width of the threshing component was 25 mm and the roller speed was 187.50 rpm, the threshing performance was optimal, with a 98.04% corn ears threshing rate and a 2.56% kernel damage rate. This paper verifies the practical applicability of the corn threshing process analysis software and provides a reference for the optimal design of threshing devices.

Vibroacoustic design optimization of curved composite shells

2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1520-S1531
Author(s):  
Rilwan K Apalowo ◽  
Dimitrios Chronopoulos
Keyword(s):  
Optimal Design ◽  
Structural Design ◽  
Composite Structures ◽  
Sensitivity Analyses ◽  
Computational Time ◽  
Design Parameters ◽  
Sandwich Shell ◽  
Acoustic Transmission ◽  
Composite Shells ◽  
Model Composite

The need to simultaneously optimize the structural design properties, and attain a satisfactory vibroacoustic performance for composite structures, has been a challenging task for modern structural engineers. This work is aimed at developing a statistical energy analysis (SEA) based numerical scheme for computing the optimal design parameters of each individual layer of layered curved shells having arbitrary complexities and layering. The main novelty of the work focuses on the computation of SEA properties for curved composite shells and derive the sensitivities of the acoustic transmission coefficient, expressed through the computed SEA properties, with respect to the structural design characteristics to be optimized. A wave finite element approach is employed to calculate the wave propagation constants of the curved shell. The calculated wave constants are then applied to compute the vibroacoustic properties for the curved shell using a SEA approach. Sensitivity analyses are conducted on the vibroacoustic properties to estimate their response to changes in the structural properties. Gradient vector is then formulated and hence the Hessian matrix, which is employed to formulate a Newton-like optimisation algorithm for optimizing the properties of the layered composite shell. The developed scheme is applied to a sandwich shell; optimal design parameters of [Formula: see text] and [Formula: see text] are obtained for the facesheet and the core of the shell whose base parameters are [Formula: see text] and [Formula: see text], respectively. This simultaneously optimizes the structure with maximum stiffness and minimum mass and attains a satisfactory dynamic performance for acoustic transmission through the sandwich shell. The principal advantage of the scheme is the ability to accurately model composite panels of arbitrary curvature at a rational computational time.

Derivatives and Parameter Designs of Arbitrary Cross-Section Inhomogenous Beams’ Modes

2013 ◽  
Author(s):  
J. W. Xing ◽  
G. T. Zheng
Keyword(s):  
Cantilever Beam ◽  
Cross Section ◽  
Analytical Solutions ◽  
Structural Parameters ◽  
Arbitrary Cross Section ◽  
Mode Shapes ◽  
Design Parameters ◽  
Structural Parameter ◽  
Highly Sensitive ◽  
Sensitivity Analysis Method

As highly sensitive to structural parameter variations, it is necessary to study relations between derivatives of displacement modes and structural design parameters. This paper proposes an integral technique for obtaining the analytical solutions of slope and curvature modes of arbitrary cross-section inhomogeneous cantilever beam. The method is validated by comparing the computation results of modal frequencies and shapes with both numerical and analytical solutions. Furthermore, based on the presented method, we have established explicit expressions for the structural parameters sensitivity of the slope/curvature mode shapes. An example of parameter design is also presented for a cantilever beam with the proposed sensitivity analysis method.

Optimal Design of a New Type of Savonius Rotor Using Simulation Analysis

2012 ◽  
Vol 499 ◽  
pp. 120-125 ◽  
Author(s):  
Zhi Peng Tang ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
Q. Yao
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Optimal Design ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Sliding Mesh ◽  
Savonius Rotor ◽  
Mesh Method ◽  
New Type

In order to enhance the efficiency of the Savonius rotor, this paper designs a new type of Savonius rotor with a rectifier. By using Computational Fluid Dynamics software to simulate and optimize the various parameters which affect the efficiency of the rotor. The sliding mesh method is applied here. The Cp-λ curves of wind turbine with different structural parameters are obtained after numerical simulation of flow field. On this basis, this paper gets the optimal structural parameters. And the results indicated that this new type of Savonius rotor has great improvement of efficiency compared with the traditional Savonius-type rotor.

Structure Optimal Design of Pneumatic 6-DOF Parallel Robot Based on Natural Frequency

2010 ◽  
Vol 450 ◽  
pp. 349-352 ◽  
Author(s):  
Bo Wu ◽  
Li Xu ◽  
Xiao Dong Yu ◽  
Zhi Wei Wang ◽  
He Xu
Keyword(s):  
Mathematical Model ◽  
Optimal Design ◽  
Natural Frequency ◽  
Dynamic Equation ◽  
Structural Design ◽  
Optimization Design ◽  
Structural Parameters ◽  
Parallel Robot ◽  
Optimization Rule ◽  
Design Aspect

. In order to improve the dynamic response rapidity and positioning precision for pneumatic 6-DOF parallel robot from the structural design aspect, a mathematical model of natural frequency for the parallel robot is developed based on dynamic equation by using vibration theory. The influences of structural parameters on minimal natural frequency are analyzed by simulation and an optimization rule of structural parameters based on minimal natural frequency is proposed. The optimization rule has advantages of simplification and efficiency, which provides a new theoretical gist for optimization of structural parameters as well as for checking the results of the actual natural frequency for pneumatic 6-DOF parallel robot. And this new rule is also valuable for structural optimization design of other similar parallel robot.

The Optimal Structural Parameters of Embedded High-Power Microwave Components Based on RSM-GA

2011 ◽  
Vol 199-200 ◽  
pp. 1537-1540
Author(s):  
Pin Chen ◽  
Zhao Hua Wu ◽  
Sheng Zhang ◽  
Tang Wen Bi ◽  
Qing Song Xiong
Keyword(s):  
Thermal Resistance ◽  
Parameter Optimization ◽  
High Power ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Thermal Design ◽  
Maximum Temperature ◽  
Structural Parameter ◽  
Substrate Thickness ◽  
Microwave Components

In the thermal design of embedded high-power chips microwave modules, structural parameter is one of the main reasons affect the thermal resistance, thus influences the reliability of the modules, the structural parameter optimized of the microwave components was studied in this paper. The goal of this work is to decrease the temperature and achieves the best structural dimensions. Using the ANSYS software build the EPCM module, through simulation analysis, Linear regression equation be fitted by RSM, which concerning the module maximum temperature with board area, substrate thickness, molybdenum thickness and encapsulation thickness. Based on genetic algorithms, structural parameter optimization algorithm of thermal model was proposed and the optimization structural parameter of embedded high-power chips microwave modules was achieved by corresponding optimization program. Based on ANSYS work, before optimization the model of maximum temperature is 86.717°C, the maximum temperature module of the optimization structural parameter is lower 1.28°C than before, so the thermal resistance decreased. The result show that the maximum temperature module of the optimization structural parameter is in good accord with the FEA results. It turns out that the RSM –GA approach proposed in this work can be effective and robust in providing structural parameter optimization in EPCM.

scholarly journals Some Remarks on the Choice of Ductility Class for Earthquake-Resistant Steel Structures

2013 ◽  
Vol 21 (3) ◽  
pp. 1-10
Author(s):  
Miroslava Matejčeková-Farhat ◽  
Rudolf Ároch
Keyword(s):  
Structural Design ◽  
Design Procedure ◽  
Steel Structures ◽  
Design Parameters ◽  
Eurocode 8 ◽  
Design Practice ◽  
Earthquake Resistant ◽  
Earthquake Resistant Structures ◽  
Design Requirements ◽  
National Practice

Abstract The implementation of the Eurocodes in current structural design practice has brought about a new emphasis on the design of earthquake-resistant structures. In some European countries, new earthquake zones have been defined; henceforth, the design requirements of many ongoing projects have changed as well. The choice of the ductility class of steel structures as one of the key design parameters, the consequences of this choice on design procedure, and some applications of the Eurocode 8 design criteria by comparing French and Slovak national practice are discussed, using a practical example of a structure.

Structural Parameter Optimization and Simulation Analysis of the Chemical Sensor Support for Food Safety Detection

2010 ◽  
Vol 439-440 ◽  
pp. 875-879
Author(s):  
Fu Zhao ◽  
Ping Wang ◽  
Yan Jue Gong ◽  
Li Zhang ◽  
Chun Ling Meng
Keyword(s):  
Food Safety ◽  
Chemical Sensor ◽  
Simulation Analysis ◽  
Structural Parameters ◽  
Dynamic Stiffness ◽  
Optimization Method ◽  
Structural Parameter ◽  
Element Analysis ◽  
Food Detection ◽  
Optimization And Simulation

This paper focuses on the structural optimization of chemical sensor support for food safety detection. The mechanical characteristic of chemical sensor support is influenced greatly by its structural parameters. Aiming at improving dynamic stiffness of the support, the modal analysis is implemented with the dynamic theory and the finite element analysis. And a group of rational structure parameters are determined through the optimum calculation. The validity simulation of the optimization is verified by the analyses of the random vibration and harmonic response. The results demonstrate that the performance of the support of the chemical sensor applied for the food detection is enhanced greatly by the presented optimization method here.

scholarly journals The Effects of Structural Parameter Variation on Cable Force of Fast Cable-Net Structure

2014 ◽  
Vol 6 ◽  
pp. 912158
Author(s):  
Qiming Wang ◽  
Peng Jiang ◽  
Xu Kong
Keyword(s):  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Structural Parameters ◽  
Element Model ◽  
Design Parameters ◽  
Structural Parameter ◽  
Global Sensitivity ◽  
Fatigue Stress ◽  
Cutting Length ◽  
Cable Force

Five-hundred-meter aperture spherical radio telescope (FAST) is supported by a cable-net structure, which enables its surface to form a real-time paraboloid by active control. FAST project is currently in the construction and implementation stage. However, there are always a considerable amount of errors that existed in practice which may result in the deviation of the structure from its ideal model or design. Therefore, structural parameter sensitivity analysis was discussed, which is indispensable. However, such deformation operation would lead to about 500 MPa of fatigue stress variation amplitude in the cable-net structure. Optimized deformation strategy is proposed to release the fatigue stress of the cable-net structure, which would be of advantage to improve the reliability of the cable-net structure. In the paper, the variation ranges of structural parameters were rationally determined. Based on local sensitivity analysis and global sensitivity analysis method, finite element model was used to study the effect of different structural parameters on the static behavior. It can be concluded that the effect of several key design parameters such as the cutting length and the elastic modulus of cable on the cable force is significant. The global sensitivity analysis indicates that the cable force range of the cable-net is −19% to 27%.

Study on Probabilistic Optimal Design of Diaphragm Spring

2010 ◽  
Vol 148-149 ◽  
pp. 1057-1061 ◽  
Author(s):  
Ruo Ping Wang ◽  
Guo Dong Zhang ◽  
Xiang Gao ◽  
Chang Gao Xia
Keyword(s):  
Optimal Design ◽  
Mass Production ◽  
Structural Parameters ◽  
Design Parameters ◽  
Optimal Result ◽  
Edge Point ◽  
Root Cause ◽  
Spring Clutch ◽  
The Mathematical Model ◽  
Method Of Design

The mathematical model of probabilistic optimization is established for diaphragm spring. The process and the method of design with an example are presented. The result shows the model and the method of design are feasible, and perfect optimal result is attained. Vehicle has mass production and its conditions of use are changeable, which determine design parameters and operating parameters of its parts have complex randomness. Diaphragm spring clutch is now widely used by many kinds of vehicles. Research of diaphragm spring parameters’ probabilistic and statistics model and the study of its optimal design have great significance for the design, R & D, manufacturing and use of automotive products and parts. Studies in the references[1,2,3] have shown that the root cause of diaphragm spring’s fatigue fracture is the original crackles near the concave inner edge point, so there is a need to do probabilistic optimal design for diaphragm spring’s structural parameters to improve the fatigue life.

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