Lightweight Analysis of Torsion Spring Based on Reliability Constraint in Multi-Failure Modes

2011 ◽  
Vol 308-310 ◽  
pp. 494-498
Author(s):  
Mei Wang ◽  
Guo Ding Chen ◽  
Yong Xiao
Keyword(s):  
Optimization Design ◽  
Failure Modes ◽  
Optimization Method ◽  
Strength Distribution ◽  
Operating Conditions ◽  
Reliability Model ◽  
Constraint Condition ◽  
Interference Theory ◽  
Torsion Spring ◽  
Reliability Constraint

The generalized stress and strength distribution interference theory is introduced to establish the reliability model of torsion spring in multi-failure modes. Using it as constraint condition, the lightweight optimization model of torsion spring based on reliability constraint in multi-failure modes is presented. And then an optimization design for a given structure of torsion spring is made to use the theoretical model under operating conditions and the reliability constraint. The weight of the opti-mized torsion spring is lighter than that of non-optimization. This verified the validity of the opti-mization method. The optimization method may contribution to design of aerospace equipments which demand strictly in weight.

Reliability Model of Gear With Correlated Failure Modes Based on Joint Distribution

2014 ◽  
Author(s):  
Lai Yue-Hua ◽  
Dong Hai-Ping ◽  
Yi Xiao-Jian ◽  
Ding Juan ◽  
Lei Hua-Jin
Keyword(s):  
Joint Distribution ◽  
Failure Modes ◽  
Physical Models ◽  
Total Probability ◽  
Traditional Model ◽  
Reliability Model ◽  
Interference Theory ◽  
Calculation Results ◽  
Set Up ◽  
Total Probability Theorem

In this paper, a precise reliability model for gear with correlated failure modes is presented. Firstly, physical models of stress and strength are set up against two main failure modes of a gear respectively. Then, the corresponding performance functions to the two failure modes are obtained according to stress-strength interference theory regarding randomness of variables in physical models of stress and strength. Furthermore, joint distribution of the two performance functions is deduced by Total Probability Theorem considering the correlation of random variables. So, reliability of a gear with correlated failure modes can be computed based on the joint distribution. Finally, an example is given and in this example the precise reliability model based on joint distribution and the traditional reliability model without considering the correlation of failure modes, are respectively adopted to calculate reliability of a gear. The calculation results are compared with that by Monte Carlo simulation and the compared results show that the gear’s reliability obtained by considering correlation of failure modes based on joint distribution is more accurate than that by the traditional model without considering the correlation of failure modes.

Structural Topology Optimization of the Column of Form Grinding Machine

2010 ◽  
Vol 455 ◽  
pp. 397-401
Author(s):  
S.G. Yao ◽  
Hang Li
Keyword(s):  
Topology Optimization ◽  
Optimization Design ◽  
Optimization Method ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Constraint Condition ◽  
Structural Dynamic ◽  
Structural Dynamic Model ◽  
Grinding Machine ◽  
Topology Optimization Method

Based on Topology optimization method of continuum the structural dynamic model has been built by constraint condition of volume and objective function of column natural frequency. In order to improve precision the dynamic characteristics of non-design region have been considered in optimization process. The column of structural optimization design has been done by applying topology optimization. The quality has not only reduced, but also the dynamic characteristic of the column has been improved. Thus the design effect has been reached.

Applied Technology in Optimization Design of Pile-Anchor Support for Foundation Pit Based on BP Neural Network

2014 ◽  
Vol 910 ◽  
pp. 419-424
Author(s):  
Dong Wei Cao ◽  
Lu De Zou
Keyword(s):  
Neural Network ◽  
Prediction Model ◽  
Bp Neural Network ◽  
Optimization Design ◽  
Optimization Method ◽  
Engineering Optimization ◽  
Constraint Condition ◽  
Foundation Pit ◽  
Random Samples ◽  
Applied Technology

A new optimization method of pile-anchor support for foundation pit based on BP neural network was been proposed and applied in engineering example. Uniform test can be used to construct study samples efficiently. BP neural network is taken advantage to build a prediction model and predicting results of large number of random samples. Then, according to the constraint condition of optimization criterions, the best optimization result screened out from results. Through an engineering optimization example, it is showed that this method is efficient and with good economic and practical value.

Parameter study and optimization design of a hat oblique tunnel portal

2021 ◽  
pp. 095440972110140
Author(s):  
Zijian Guo ◽  
Tanghong Liu ◽  
Wenhui Li ◽  
Yutao Xia
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Pareto Front ◽  
Optimization Problem ◽  
Optimization Method ◽  
Design Parameters ◽  
Parameter Study ◽  
Buffer Structure ◽  
Tunnel Entrance ◽  
The Ideal

The present work focuses on the aerodynamic problems resulting from a high-speed train (HST) passing through a tunnel. Numerical simulations were employed to obtain the numerical results, and they were verified by a moving-model test. Two responses, [Formula: see text] (coefficient of the peak-to-peak pressure of a single fluctuation) and[Formula: see text] (pressure value of micro-pressure wave), were studied with regard to the three building parameters of the portal-hat buffer structure of the tunnel entrance and exit. The MOPSO (multi-objective particle swarm optimization) method was employed to solve the optimization problem in order to find the minimum [Formula: see text] and[Formula: see text]. Results showed that the effects of the three design parameters on [Formula: see text] were not monotonous, and the influences of[Formula: see text] (the oblique angle of the portal) and [Formula: see text] (the height of the hat structure) were more significant than that of[Formula: see text] (the angle between the vertical line of the portal and the hat). Monotonically decreasing responses were found in [Formula: see text] for [Formula: see text] and[Formula: see text]. The Pareto front of [Formula: see text] and[Formula: see text]was obtained. The ideal single-objective optimums for each response located at the ends of the Pareto front had values of 1.0560 for [Formula: see text] and 101.8 Pa for[Formula: see text].

scholarly journals Mechanical properties optimization of the steering column based on multi-objective optimization design

2016 ◽  
Vol 8 (12) ◽  
pp. 168781401668294 ◽  
Author(s):  
Si Chen ◽  
Zhaohui Wang ◽  
Mi Lv
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Optimization Design ◽  
Strain Difference ◽  
Optimization Method ◽  
Equivalent Strain ◽  
Multi Objective Optimization ◽  
Optimal Process ◽  
Multi Objective ◽  
Initial Results

The mechanical properties of the steering column have a significant influence on the comfort and stability of a vehicle. In order for the mechanical properties to be improved, the rotary swaging process of the steering column is studied in this article. The process parameters, including axial feed rate, hammerhead speed, and hammerhead radial reduction, are systematically analyzed and optimized based on a multi-objective optimization design. The response surface methodology and the genetic algorithm are employed for optimal process parameters to be obtained. The maximum damage value, the maximum forming load, and the equivalent strain difference obtained with the optimal process parameters are, respectively, decreased by 30.09%, 7.44%, and 57.29% compared to the initial results. The comparative results present that the quality of the steering column is improved. The torque experiments and fatigue experiments are conducted with the optimal steering column. The maximum torque is measured to be 260 NM, and the service life is measured to be 2 weeks (40 NM, 2500 times), which are, respectively, increased by 8.3% and 8.69% compared to the initial results. The above results display that the mechanical properties of the steering column are optimized to verify the feasibility of the multi-objective optimization method.

The Role of Offshore Monitoring in an Effective Deepwater Riser Integrity Management Program

2007 ◽  
Author(s):  
Brittany Goldsmith ◽  
Elizabeth Foyt ◽  
Madhu Hariharan
Keyword(s):  
Failure Modes ◽  
Human Life ◽  
Management Program ◽  
Measured Data ◽  
Operating Conditions ◽  
Environmental Damage ◽  
Positioning Systems ◽  
Integrity Management ◽  
Deepwater Riser

As offshore field developments move into deeper water, one of the greatest challenges is in designing riser systems capable of overcoming the added risks of more severe environments, complicated well requirements and uncertainty of operating conditions. The failure of a primary riser component could lead to unacceptable consequences, including environmental damage, lost production and possible injury or loss of human life. Identification of the risks facing riser systems and management of these risks are essential to ensure that riser systems operate without failure. Operators have recognized the importance of installing instrumentation such as global positioning systems (GPS), vessel motion measurement packages, wind and wave sensors and Acoustic Doppler Current Profiler (ADCP) units to monitor vessel motions and environmental conditions. Additionally, high precision monitoring equipment has been developed for capturing riser response. Measured data from these instruments allow an operator to determine when the limits of acceptable response, predicted by analysis or determined by physical limitations of the riser components, have been exceeded. Regular processing of measured data through automated routines ensures that integrity can be quickly assessed. This is particularly important following extreme events, such as a hurricane or loop current. High and medium alert levels are set for each parameter, based on design analysis and operating data. Measured data is compared with these alert levels, and when an alert level is reached, further response evaluation or inspection of the components in question is recommended. This paper will describe the role of offshore monitoring in an integrity management program and discuss the development of alert levels based on potential failure modes of the riser systems. The paper will further demonstrate how this process is key for an effective integrity management program for deepwater riser systems.

A Systematic Optimization Design Method for Thermal Management of Passenger Vehicles

2021 ◽  
pp. 1-27
Author(s):  
Jie Zhang ◽  
Qidong Wang ◽  
Han Zhang ◽  
Min Zhang ◽  
Jianwei Lin
Keyword(s):  
Prediction Model ◽  
Surface Temperature ◽  
Thermal Management ◽  
Optimization Design ◽  
Cfd Simulation ◽  
Optimal Solution ◽  
Optimization Method ◽  
Drive Shaft ◽  
Management Problem ◽  
Systematic Optimization

Abstract In this study, a systematic optimization method for the thermal management problem of passenger vehicle was proposed. This article addressed the problem of the drive shaft sheath surface temperature exceeded allowable value. Initially, the causes and initial measures of the thermal problem were studied through computational fluid dynamics (CFD) simulation. Furthermore, the key measures and the relevant parameters were determined through Taguchi method and significance analysis. A prediction model between the parameters and optimization objective was built by radial basis function neural network (RBFNN). Finally, the prediction model and particle swarm optimization (PSO) algorithm were combined to calculate the optimal solution, and the optimal solution was selected for simulation and experiment verification. Experiment results indicated that this method reduced the drive shaft sheath surface temperature promptly, the decreasing amplitude was 22%, which was met the experimental requirements.

An Optimization Design Platform for Fir-Tree Root and Groove for Steam Turbine

2018 ◽  
Author(s):  
Deqi Yu ◽  
Xiaojun Zhang ◽  
Jiandao Yang ◽  
Kai Cheng ◽  
Weilin Shu ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Steam Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Optimization Design ◽  
Turbine Blades ◽  
Local Stress ◽  
Optimization Method ◽  
Steam Turbines ◽  
Geometry Configuration

Fir-tree root and groove profiles are widely used in gas turbine and steam turbine. Normally, the fir-tree root and groove are characterized with straight line, arc or even elliptic fillet and splines, then the parameters of these features were defined as design variables to perform root profile optimization. In ultra-long blades of CCPP and nuclear steam turbines and high-speed blades of industrial steam turbine blades, both the root and groove strength are the key challenges during the design process. Especially, in industrial steam turbines, the geometry of blade is very small but the operation velocity is very high and the blade suffers stress concentration severely. In this paper, two methods for geometry configuration and relevant optimization programs are described. The first one is feature-based using straight lines and arcs to configure the fir-tree root and groove geometry and genetic algorithm for optimization. This method is quite fit for wholly new root and groove design. And the second local optimization method is based on B-splines to configure the geometry where the local stress concentration occurs and the relevant optimization algorithm is used for optimization. Also, several cases are studied as comparison by using the optimization design platform. It can be used not only in steam turbines but also in gas turbines.

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

scholarly journals Optimization Design of the Over-All Dimensions of Centrifugal Compressor Stage

1988 ◽  
Author(s):  
Wang Qinghuan ◽  
Sun Zhiqin
Keyword(s):  
Centrifugal Compressor ◽  
Computer Aided Design ◽  
Optimization Design ◽  
Optimization Method ◽  
Complex Method ◽  
Compressor Stage ◽  
Local Optima ◽  
Centrifugal Compressor Stage ◽  
Optimum Solution ◽  
Nonlinear Objective Function

A new procedure employed in computer-aided design of centrifugal compressor stage to determine its over-all dimensions is described in this paper. By the use of the COMPLEX METHOD, the arbitrary number of variables to be optimized can be specified to remove the hidden danger of the local optima which stems from adopting a few, for example two or three, variables to be optimized. This procedure is available for any complicated implicit nonlinear objective function and ensures establishment of a true optimum solution. Numerical calculations have been carried out by using the computer program described here to check the ability of the optimization method. The results obtained by the calculations agree fairly well with that obtained by experiments.

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