STRUCTURAL OPTIMIZATION ALGORITHM FOR VEHICLE SUSPENSIONS

Author(s):  
Marc J. Richard ◽  
Mohamed Bouazara ◽  
Laouhari Khadir ◽  
Guoqiang Q. Cai

Stringent tolerances on mechanical components have created increasingly severe demands on the quality of new mechanical designs. The mathematical models used to analyze the various types of mechanical systems these days need to incorporate an optimization algorithm capable of minimizing the levels of vibrations coming from varied sources. The suggested method is based on the parallel combination of three methods; the Rayleigh-Ritz approach (to determine the first eigenfrequencies) which is incorporated into an efficient multicriterion optimization process based on the ESO (Evolutionary Structural Optimization) method and the finite element software ABAQUS. The analytical resolution and the numerical calculations of the mechanical component are, finally, validated by an experimental set-up which exploits a frequency analyser, acceleration sensors and an excitation hammer. The effectiveness of this approach is also demonstrated in the analysis of an upper car suspension arm. By gradually removing material from the initial car suspension design, the frequency of the component can be controlled in order to optimize the structural constraints.

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3230 ◽  
Author(s):  
Puyang Zhang ◽  
Yunlong Xu ◽  
Conghuan Le ◽  
Hongyan Ding ◽  
Yaohua Guo

A two-step structural optimization method was proposed to select the transition section of a composite bucket foundation (CBF). In the first step, based on the variable density method, a solid isotropic microstructures with penalization (SIMP) interpolation model was established under specific load conditions and boundary conditions. The solution of force transmission path and the topology of the transition section in six forms (e.g., linear, arc-shaped, linear thin-walled, and arc-shaped thin-walled) were optimized. Afterwards, finite element software ABAQUS was used to verify this model. Results show that the utilization rate of the arc-shaped thin-walled structure was the largest, and its basic transmission force was more straightforward together with smaller cross-section size at the same height and smaller influence on spoiler flow. In the second step, the detailed optimization of CBF was carried out using mathematical programming. Under the premise of minimum total construction cost, the body shape parameters of each part were set as design variables satisfying the corresponding strength, stiffness, and stability conditions; meanwhile, the minimum total structure weight was set as the objective function. MATLAB was used to solve the sequence quadratic programming (SQP) algorithm and hybrid genetic algorithm, and the optimal body parameters were obtained.


2012 ◽  
Vol 198-199 ◽  
pp. 1550-1553 ◽  
Author(s):  
Hui Zhao ◽  
Ming Wang ◽  
Hong Jun Wang ◽  
You Jun Yue

The sintering blending is a complex nonlinear optimization problem. The traditional single algorithm can not meet the requirement of good quality of sinter and lowest costs well. So, a hybrid optimization method of particle swarm and ant colony algorithm was proposed. The method gives full play to the global convergence of particle swarm optimization algorithm, takes it as a preliminary search, then use the positive feedback mechanism of ant colony algorithm for the exact solution, to make these two algorithms to reach a complementary, in order to get a rapid exact solution. The simulation results show that the proposed hybrid algorithm has fast convergence and high accuracy, which can effectively reduce the sintering cost.


2010 ◽  
Vol 40-41 ◽  
pp. 577-583
Author(s):  
Zhen Hua ◽  
Ye Wei Li ◽  
Jin Jiang Li

The purpose of image optimization is that the salient region of image is stand out, and is layout an image met the demand. The existed image optimization method is summarized, and their advantages and disadvantages respectively analyzed. The improved visual attention model is described, and is used to detect the salient region of image. The parameters of image optimization are calculated by the optimization function of image layout rules. At last, the weights of the images optimized parameters are adjusted by the image layout and adjustment function based on image optimized parameters, to achieve image layout and obtain the most optimal image, to realize image optimization. Experimental results validate that this methods not only achieve image optimization, but also accurately and automatically achieve to shorten distance and enlarge salient regions, improve the quality of the image optimization, and has good robustness.


At production of fabrics, including fabrics for agricultural purpose, an important role is played by the cor-rect adjustment of operation of machine main regulator. The quality of setup of machine main controller is determined by the proper selection of rotation angle of warp beam weaving per one filling thread. In the pro-cess of using the regulator as a result of mistakes in adjustment, wear of transmission gear and backlashes in connections of details there are random changes in threads length. The purpose of the article is the research of property of random errors of basis giving by STB machine regulator. Mistakes can be both negative, and positive. In case of emergence only negative or only positive mistakes operation of the machine becomes im-possible as there will be a consecutive accumulation of mistakes. As a result of experimental data processing for stable process of weaving and the invariable diameter of basis threads winding of threads it is revealed that the random error of giving is set up as linear function of the accidental length having normal distribution. Measurements of accidental deviations in giving of a basis by the main regulator allowed to construct a curve of normal distribution of its actual length for one pass of weft thread. The presented curve of distribution of random errors in giving of a basis is the displaced curve of normal distribution of the accidental sizes. Also we define the density of probability of normal distribution of basis giving errors connected with a margin er-ror operation of the main regulator knowing of which allows to plan ways of their decrease that is important for improvement of quality of the produced fabrics.


1991 ◽  
Vol 24 (10) ◽  
pp. 171-177
Author(s):  
T. Vellinga ◽  
J. P. J. Nijssen

Much of the material dredged from the port of Rotterdam is contaminated to such a degree that it must be placed in specially constructed sites. The aim of Rotterdam is to ensure that the dredged material will once again be clean. This will entail the thorough cleansing of the sources of the contamination of the sediment in the harbours and in the River Rhine. The Rotterdam Rhine Research Project (RRP) is one of the means to achieve this based on: technical research, legal research, public relations and dialogues with dischargers. The programme for five selected heavy metals is almost complete. For many heavy metal discharge points between Rotterdam and Rheinfelden, a specially devised independent load assessment has been carried out four times. Balance studies were used to determine the relative contributions of the point discharges to the total. Currently the results are being used in an attempt to negotiate agreements with a selected number of the major dischargers. At present, more detailed balance studies are being set up and exploratory measurements carried out for organic micropollutants. It may be concluded that the research is progressing successfully and methods and techniques developed seem satisfactory and broadly applicable. The Rhine Action Programme encompasses an international effort to improve the quality of the Rhine water. Although the RRP plays a modest complementary role to the Rhine Action Plan, there is no doubt of the value of this Rotterdam initiative. The mode of work followed in the RRP contains elements that can be of use in combatting the contamination of the North Sea by rivers other than the Rhine.


1988 ◽  
Vol 20 (4-5) ◽  
pp. 249-251
Author(s):  
Jacques Bernard

The flow and the water quality of the rivers vary throughout the year. Very frequently the environment protection authorities set up a quality objective for the river water and this mini mum quality level is constant. So, it wou1d seem possible to accept variable quality standards for plant effluents. A first approach of the problem,by a small French task group,based on three actual cases leads to the provisory conclusion that such a regulation is suitable and presents economical benefit only in some very limit ed cases.


2015 ◽  
Vol 3 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Achin Jain ◽  
M P Venkatesh M P ◽  
Pramod T.M. Kumar

In Tanzania, Tanzania Food and Drugs Authority (TFDA), is a regulatory body responsible for controlling the quality,safety and effectiveness of food, drugs, herbal drugs, cosmetics and medical devices. The Authority has been ensuringsafety, efficacy and quality of medicines by quality control tests; in addition to other quality assessment mechanisms.The guidelines laid by TFDA have also emanated from commitment to democracy and gives strong emphasis to thefulfilment of the needs of the less privileged rural population.Tanzania is an emerging market; the pharmaceutical market is valued at over US$250 million, and is growing at anannual rate of around 16.5% and is expected to reach approximately US$550 billion in 2020. Currently, the market ishighly dependent on imports, which account for around 75% of the total pharmaceutical market.The procedures and approval requirements of new drugs, variations, import, export and disposal have been set up bythe TFDA, which help in maintaining quality of the drug products that are imported as well being produced locally 


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