Optimum Design of an Archery Twin Round-Wheel Compound Bow

Author(s):  
Onur Denizhan ◽  
Meng-Sang Chew

Abstract In this article, an optimization of a twin round-wheel compound bow is presented. Based on a previously published mathematical model of the kineto-elastic system, an objective function is introduced to maximize the stored potential energy in the compound bow limbs. The optimized design of the compound bow shows an increase in the potential energy stored for the same drawn distance. However, a slightly higher force is required and the initial position of string is slightly closer to the riser. Two different optimality criteria are also discussed.

2009 ◽  
Vol 626-627 ◽  
pp. 693-698
Author(s):  
Yong Yong Zhu ◽  
S.Y. Gao

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.


2013 ◽  
Vol 416-417 ◽  
pp. 1120-1125
Author(s):  
Zhen Jun He ◽  
Peng Xu ◽  
Jian Rong Lu

To demonstrate the importance of abrasion and clearance to machinery, this paper studied abrasion of Cam mechanism contact surface, illustrated how abrasion and clearance relate to each other and investigated how they influence kinematic accuracy of the mechanism. In the case of Cam mechanism with flat-bottomed translation follower, it elaborated abrasion styles and bad points and depicted heart-shaped abrasion rate curve. It proposed a mathematical model and optimized design for cam profile, taking abrasion design as an objective function. Aided by Matlab and its optimization toolbox, it also proposed a optimized solution to the objective function mathematical model. And powered by computing capabilities of Matlab, it determined the coefficients in a high-order five-term function and found the optimal value of the objective function quickly in need. By optimization, mechanism abrasion improves and its kinematic accuracy and reliability increase, prolong its life.


10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.


1999 ◽  
Vol 122 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Hiromu Hashimoto ◽  
Yasuhisa Hattori

The aim of this paper is to develop a general methodology for the optimum design of magnetic head sliders in improving the spacing characteristics between a slider and disk surface under static and dynamic operating conditions of hard disk drives and to present an application of the methodology to the IBM 3380-type slider design. To generate the optimal design variables, the objective function is defined as the weighted sum of the minimum spacing, the maximum difference in the spacing due to variation of the radial location of the head, and the maximum amplitude ratio of the slider motion. Slider rail width, taper length, taper angle, suspension position, and preload are selected as the design variables. Before the optimization of the head, the effects of these five design variables on the objective function are examined by a parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique, combining the direct search method and successive quadratic programming. From the obtained results, the effectiveness of optimum design on the spacing characteristics of magnetic heads is clarified. [S0742-4787(00)03701-2]


2021 ◽  
Author(s):  
Onur Denizhan ◽  
Meng-Sang Chew
Keyword(s):  

Author(s):  
Yasuhisa Hattori ◽  
Hiromu Hashimoto ◽  
Masayuki Ochiai

Abstract The aim of this paper is to develop the general methodology for the optimum design of magnetic head slider for improving the spacing characteristics between head slider and disk surfaces under the static and dynamic operation conditions of hard disk drive and to present an application of the methodology to IBM 3380-type slider design. In the optimum design, the objective function is defined as the weighted sum of minimum spacing, maximum difference of spacing due to variation of radial location of head and maximum amplitude ratio of slider motion. Slider rail width, taper length, taper angle, suspension position and preload are selected as the design variables. Before the optimization of magnetic head slider, the effects of these five design variables on the objective function are examined by the parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique combining the direct search method and the successive quadratic programming (SQP). From the results obtained, the effectiveness of optimum design on the spacing characteristics of magnetic head slider is clarified.


2016 ◽  
Author(s):  
Marcel Fajkus ◽  
Jan Nedoma ◽  
Stanislav Kepak ◽  
Lukas Rapant ◽  
Radek Martinek ◽  
...  

Author(s):  
Volodymyr Fedorov ◽  
Vladislav Kikot ◽  
Nataliya Shtefan

The article considers a two-stage gyrocompass with a rigid torsion suspension of the moving part. The principle of its action is based on balancing the elastic moment of the torsion bars with the gyroscopic moment. When this condition is met, the azimuth of the steady-state position of the rotor axis is calculated from the known kinetic moment , latitude and angular rigidity of the torsion bars, and the measured angle of rotation of the moving part of the gyroscope relative to its initial position. The “aging of the material” of the torsion bars, the effect of temperature on them, etc., leads to an uncontrolled change in the angular stiffness of the torsion bars, which, in turn, leads to an error in determining the position of the meridian. A method is proposed for determining the position of the meridian under conditions when the angular stiffness of the torsion is unknown. The method involves observing the motion of the gyroscope in a mode where the kinetic momentum changes linearly (the rotor accelerates). This movement is associated with the movement of the mathematical model of a two-stage gyrocompass in the same mode in the form of a differential equation of motion or in the form of its solution. As a result of minimizing the discrepancy between the real movement of the gyrocompass and the movement of its mathematical model, the “best estimate” of the parameter characterizing the position of the meridian and the “best estimate” of the angular stiffness of the torsion bars in this dimension are found. The results of modeling the corresponding information processing algorithms are considered. The advantages of the proposed method compared with traditional methods are indicated .


2013 ◽  
Vol 61 (2) ◽  
pp. 185-191
Author(s):  
Md Hasib Uddin Molla ◽  
M Babul Hasan

Formulation of LPs and IPs is a technique to convert real life decision problems into a mathematical model. This model consists of a linear objective function and a set of linear constraints expressed in the form of a system of equations or inequalities. In this paper, we present formulation from real life problem as an art. We discuss formulation through real life example and solve them using computer techniques AMPL and LINDO. DOI: http://dx.doi.org/10.3329/dujs.v61i2.17068 Dhaka Univ. J. Sci. 61(2): 185-191, 2013 (July)


2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.


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