Sequential Quadratic Programming and Dynamic Optimal Design of Rotating Blades*, †

1983 ◽  
Vol 11 (4) ◽  
pp. 451-464 ◽  
Author(s):  
Cheng Kengtung ◽  
Yuanxlan Gu
2021 ◽  
Vol 263 ◽  
pp. 03007
Author(s):  
Vladimir Mavzovin ◽  
Igor Ovchinnikov

The problems of optimal design of metal structures are usually formulated as the problem of finding such values of the selected parameters of structures that provide the smallest (or largest) value of the selected optimality criterion in the area of admissible design solutions. In most works on the optimization of metal structures, parametric problems are considered, limited by the preliminary assignment of a constructive form with the possibility of changing its parameters. To solve these problems, both deterministic and probabilistic optimization models can be used. A deterministic problem of optimal design of flexible round metal plates exposed to the combined action of a load and an aggressive environment causing corrosive wear of one of the plate surfaces is considered. A feature of the statement is that it takes into account the effect of the stressed state of the plates on the kinetics of their corrosive wear. Due to the insufficient efficiency of random search methods, the sequential quadratic programming technique is used. Two formulations of the optimal design problem are formulated, which are reduced to the minimax problem. 8 optimization projects were considered, their comparative analysis was carried out. It is shown that the realization of the found optimal thickness profiles leads either to a significant decrease in the stress level at the end of the plate’s service life, or to a significant increase in the service life. Calculation results show that maximum fatigue life designs are equal at end-of-life, and the maximum increase in fatigue life for hard- pinned inserts along the contour is 59%. As a result of the study, it was found that the problems of optimal design of flexible round plates under conditions of corrosive wear (the rate of which depends on the level of stresses in the plates), presented in the form of a minimax problem, can be effectively solved using the sequential quadratic programming technique, and the study of time evolution is intense -strain state can be carried out using a combination of the mesh method and the Adams method. Realization of the found optimal thickness profiles leads either to a significant decrease in the stress level at the end of the plate’s service life, or to a significant increase in the service life.


2011 ◽  
Vol 86 ◽  
pp. 201-205
Author(s):  
Cong Yang Zuo ◽  
Jin Zhou

In a high-speed rotor system, vibration control is necessary to ensure steady operation of the system. Magnetic damper is one of the effective means to control the vibration. This paper is concerned with the optimal design of a passive magnetic damper’s system parameter, including its geometric and electrical parameters. The relation between the damper’s system parameter and its damping coefficient is derived. A mathematical model that maximizes the damping coefficient is built, with the constraints of the geometric and electrical parameters. The optimization program is based on the algorithm of sequential quadratic programming method. The program yields the maximum damping coefficient under the given condition of the rotor’s diameter.


2012 ◽  
Vol 625 ◽  
pp. 121-124
Author(s):  
Hui Jing ◽  
Cong Li ◽  
Fu Yun Liu ◽  
Bing Kuang

Heavy truck needs to use the vibration reduction technology to improve its quality. Nowadays, it is a useful and effective way for vibration reduction that by employing the proper Powertrain Mounting Systems (PMS) to reduce the vibration. One useful method to develop more effective mounting systems is through optimization techniques. Sequential Quadratic Programming (SQP) is an effective optimization technique. In this paper, design optimization of powertrain mounting system based on SQP method for vibration control is presented. The optimization objective is to find the highest decoupling ratio of the each mount while selecting the stiffness and orientations of individual mount. The constraints are imposed to keep the desired decoupled ratio in each orientation and the frequency corresponding to the decoupled ratio. A case study is given to validate the proposed method. The result shows that the value of optimized system, such as decoupling ratio, is improved significantly. Therefore, the method proposed in this paper is effective for the optimization of powertrain mounting system.


Author(s):  
Sharafat Ali ◽  
Iftikhar Ahmad ◽  
Muhammad Asif Zahoor Raja ◽  
Siraj ul Islam Ahmad ◽  
Muhammad Shoaib

In this research paper, an innovative bio-inspired algorithm based on evolutionary cubic splines method (CSM) has been utilized to estimate the numerical results of nonlinear ordinary differential equation Painlevé-I. The computational mechanism is used to support the proposed technique CSM and optimize the obtained results with global search technique genetic algorithms (GAs) hybridized with sequential quadratic programming (SQP) for quick refinement. Painlevé-I is solved by the proposed technique CSM-GASQP. In this process, variation of splines is implemented for various scenarios. The CSM-GASQP produces an interpolated function that is continuous upto its second derivative. Also, splines proved to be stable than a single polynomial fitted to all points, and reduce wiggles between the tabulated points. This method provides a reliable and excellent procedure for adaptation of unknown coefficients of splines by searching globally exploiting the performance of GA-SQP algorithms. The convergence, exactness and accuracy of the proposed scheme are examined through the statistical analysis for the several independent runs.


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