CAD and Optimization of Helical Torsion Springs

1994 ◽  
Author(s):  
Sayed M. Metwalli ◽  
M. Alaa Radwan ◽  
Abdel Aziz M. Elmeligy
Keyword(s):  
Iterative Process ◽  
Minimum Weight ◽  
Design Parameters ◽  
Optimal Parameters ◽  
Direct Evaluation ◽  
Torsion Spring ◽  
Performance Requirements ◽  
Design Variables ◽  
Method Of Lagrange Multipliers ◽  
Torsion Springs

Abstract The convensional procedure of helical torsion spring design is an iterative process because of large number of requirements and relations that are to be attained once at a time. The design parameters are varied at random until the spring design satisfies performance requirements. A CAD of the spring for minimum weight is formulated with and without the variation of the maximum normal stress with the wire diameter. The CAD program solves by employing the method of Lagrange-Multipliers. The optimal parameters, in a closed form are obtained, normalized and plotted. These explicit relations of design variables allow direct evaluation of optimal design objective and hence, an absolute optimum could be achieved. The comparison of optimum results with those previously published, shows a pronounced achievement in the reduction of torsion spring weight.

Integrated Structural and Control Optimization

2004 ◽  
Vol 10 (10) ◽  
pp. 1377-1391 ◽  
Author(s):  
Ijar M. Fonseca ◽  
Peter M. Bainum
Keyword(s):  
Analytical Approach ◽  
Minimum Weight ◽  
Space Structure ◽  
Design Parameters ◽  
Gravity Gradient ◽  
Control Optimization ◽  
Design Variables ◽  
Analytical Derivatives ◽  
And Control ◽  
Derivatives Of

This paper focuses on the integrated structural/control optimization of a large space structure with a robot arm subject to the gravity-gradient torque through a semi-analytical approach. It is well known that the computer effort to compute numerically derivatives of the constraints with respect to design variables makes the process expensive and time-consuming. In this sense, a semi-analytical approach may represent a good alternative when optimizing systems that require sensitivity calculations with respect to design parameters. In this study, constraints from the structure and control disciplines are imposed on the optimization process with the aim of obtaining the structure’s minimum weight and the optimum control performance. In the process optimization, the sensitivity of the constraints is computed by a semi-analytical approach. This approach combines the use of analytical derivatives of the mass and stiffness matrices with the numerical solution of the eigenvalue problem to obtain the eigenvalue derivative with respect to the design variables. The analytical derivatives are easy to obtain since our space structure is a long one-dimensional beam-like spacecraft.

Justification of design parameters of the fractional reaping conveyor and its devices for removal of beveled stems from under the wheels of the vehicle

2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych
Keyword(s):  
Optimal Design ◽  
Technological Process ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Optimal Parameters ◽  
Belt Conveyor ◽  
Grain Crops ◽  
Mode Of Operation ◽  
Optimal Values ◽  
Main Component

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.

scholarly journals Shear Behavior of a Reinforced Concrete Frame Retrofitted with a Hinged Steel Damping System

2020 ◽  
Vol 12 (24) ◽  
pp. 10360
Author(s):  
Hyun-Do Yun ◽  
Sun-Woong Kim ◽  
Wan-Shin Park ◽  
Sun-Woo Kim
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Main Research ◽  
Torsion Spring ◽  
Concrete Frame ◽  
Energy Dissipation Capacity ◽  
Research Questions ◽  
Torsion Springs

The purpose of this study was to experimentally evaluate the effect of a hinged steel damping system on the shear behavior of a nonductile reinforced concrete frame with an opening. For the experimental test, a total of three full-scale reinforced concrete frame specimens were planned, based on the “no retrofitting” (NR) specimens with non-seismic details. The main research questions were whether the hinged steel damping system is reinforced and whether torsion springs are installed in the hinged steel damping system. From the results of the experiment, the hinged steel damping system (DR specimen) was found to be effective in seismic retrofitting, while isolating the opening of the reinforced concrete (RC) frame, and the torsion spring installed at the hinged connection (DSR specimen) was evaluated to be effective in controlling the amount of deformation of the upper and lower dampers. The strength, stiffness, and energy dissipation capacity of the DSR specimen were slightly improved compared to the DR specimen, and it was confirmed that stress redistribution was induced by the rotational stiffness of the torsion spring installed in the hinge connection between the upper and lower frames.

A unified framework for the design of low-complexity wavelet filters

2017 ◽  
Vol 15 (06) ◽  
pp. 1750054 ◽  
Author(s):  
Ameya K. Naik ◽  
Raghunath S. Holambe
Keyword(s):  
Feature Extraction ◽  
Compact Support ◽  
Low Complexity ◽  
Design Parameters ◽  
Unified Framework ◽  
Vanishing Moments ◽  
Wavelet Filters ◽  
Design Variables ◽  
Optimum Filter ◽  
Simulation Results

An outline is presented for construction of wavelet filters with compact support. Our approach does not require any extensive simulations for obtaining the values of design variables like other methods. A unified framework is proposed for designing halfband polynomials with varying vanishing moments. Optimum filter pairs can then be generated by factorization of the halfband polynomial. Although these optimum wavelets have characteristics close to that of CDF 9/7 (Cohen-Daubechies-Feauveau), a compact support may not be guaranteed. Subsequently, we show that by proper choice of design parameters finite wordlength wavelet construction can be achieved. These hardware friendly wavelets are analyzed for their possible applications in image compression and feature extraction. Simulation results show that the designed wavelets give better performances as compared to standard wavelets. Moreover, the designed wavelets can be implemented with significantly reduced hardware as compared to the existing wavelets.

“IRIS” A Computerized High Head Pump Turbine Design System

1977 ◽  
Vol 99 (3) ◽  
pp. 567-577
Author(s):  
S. Chacour ◽  
J. E. Graybill
Keyword(s):  
Mechanical Design ◽  
Design Parameters ◽  
Design System ◽  
Performance Requirements ◽  
Manufacturing Process Planning ◽  
Depth Analysis ◽  
High Head ◽  
Critical Components ◽  
Limited Input Data ◽  
Turbine Design

“IRIS” is a computerized design and structural optimization system capable of generating all the major hydraulic and mechanical design parameters of high head pump/turbines from limited input data. The program will size the unit and select the proper hydraulic passage configuration according to performance requirements and optimize the dimensions of all the major components, generate command tapes used by a numerically controlled flame cutter, estimate cost, and issue manufacturing process planning. It also generates finite element models for the “in depth” analysis of critical components.

COMPLEX METHODOLOGY FOR CALCULATING THE OPTIMAL PARAMETERS OF THE HEAT RECOVERY SYSTEM OF A BOILER PLANT

2017 ◽  
Author(s):  
Nataliia Fialko ◽  
◽  
Alla Stepanova ◽  
Raisa Navrodskaia ◽  
Svetlana Shevchuk ◽  
...  
Keyword(s):  
Heat Recovery ◽  
Optimization Techniques ◽  
Planning Theory ◽  
Design Parameters ◽  
Optimal Parameters ◽  
Multilevel Optimization ◽  
Boiler Plant ◽  
Experimental Planning ◽  
Recovery System ◽  
Heat Recovery System

The results of optimizing the parameters of the heat recovery system of a boiler plant designed to heat return water are presented. The feasibility of using a technique that combines methods of exergy analysis experimental planning theory and multilevel optimization to optimize plant parameters is analyzed. It is emphasized that the efficiency of heat recovery systems optimized using the above technique is 2-3% higher than the efficiency of systems optimized using other optimization techniques. In addition, the specified method allows to take into account a significant part of the technical losses in the heat recovery system and to optimize a large number of parameters. The main stages of a comprehensive methodology are given. At each stage, the above methods are used to develop mathematical models and obtain dependences of exergy efficiency criteria on the parameters of the heat recovery system. The results of calculating the optimum values of operating and design parameters for the considered heat recovery system of the boiler unit are presented.

A Study on Optimum Design Using Fuzzy Numbers As Design Variables

1995 ◽  
Author(s):  
Masao Arakawa ◽  
Hiroshi Yamakawa
Keyword(s):  
Fuzzy Sets ◽  
Optimum Design ◽  
Fuzzy Numbers ◽  
Fuzzy Optimization ◽  
Design Parameters ◽  
Numerical Examples ◽  
Design Variables ◽  
Conventional Methods

Abstract In this study, we summerize the method of fuzzy optimization using fuzzy numbers as design variables. In order to detect flaw in fuzzy calculation, we use LR-fuzzy numbers, which is known as its simplicity in calculation. We also use simple fuzzy numbers’ operations, which was proposed in the previous papers. The proposed method has unique characteristics that we can obtain fuzzy sets in design variables (results of the design) directly from single numerical optimizing process. Which takes a large number of numerical optimizing processes when we try to obtain similar results in the conventional methods. In the numerical examples, we compare the proposed method with several other methods taking imprecision in design parameters into account, and demonstrate the effectiveness of the proposed method.

Design Sensitivity Analysis of Nonlinear Multidisciplinary Multibody Systems in the MIXEDMODELS Platform

2007 ◽  
Author(s):  
Shilpa A. Vaze ◽  
Prakash Krishnaswami ◽  
James DeVault
Keyword(s):  
Sensitivity Analysis ◽  
Multibody Systems ◽  
Design Sensitivity ◽  
Differential Algebraic Equations ◽  
The State ◽  
Design Sensitivity Analysis ◽  
Design Parameters ◽  
State Variables ◽  
Sensitivity Coefficients ◽  
Design Variables

Most state-of-the-art multibody systems are multidisciplinary and encompass a wide range of components from various domains such as electrical, mechanical, hydraulic, pneumatic, etc. The design considerations and design parameters of the system can come from any of these domains or from a combination of these domains. In order to perform analytical design sensitivity analysis on a multidisciplinary system (MDS), we first need a uniform modeling approach for this class of systems to obtain a unified mathematical model of the system. Based on this model, we can derive a unified formulation for design sensitivity analysis. In this paper, we present a modeling and design sensitivity formulation for MDS that has been successfully implemented in the MIXEDMODELS (Multidisciplinary Integrated eXtensible Engine for Driving Metamodeling, Optimization and DEsign of Large-scale Systems) platform. MIXEDMODELS is a unified analysis and design tool for MDS that is based on a procedural, symbolic-numeric architecture. This architecture allows any engineer to add components in his/her domain of expertise to the platform in a modular fashion. The symbolic engine in the MIXEDMODELS platform synthesizes the system governing equations as a unified set of non-linear differential-algebraic equations (DAE’s). These equations can then be differentiated with respect to design to obtain an additional set of DAE’s in the sensitivity coefficients of the system state variables with respect to the system’s design variables. This combined set of DAE’s can be solved numerically to obtain the solution for the state variables and state sensitivity coefficients of the system. Finally, knowing the system performance functions, we can calculate the design sensitivity coefficients of these performance functions by using the values of the state variables and state sensitivity coefficients obtained from the DAE’s. In this work we use the direct differentiation approach for sensitivity analysis, as opposed to the adjoint variable approach, for ease in error control and software implementation. The capabilities and performance of the proposed design sensitivity analysis formulation are demonstrated through a numerical example consisting of an AC rectified DC power supply driving a slider crank mechanism. In this case, the performance functions and design variables come from both electrical and mechanical domains. The results obtained were verified by perturbation analysis, and the method was shown to be very accurate and computationally viable.

Optimum Design of Anti-Siphon Device used to Prevent Cerebrospinal Fluid from Overdraining

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1374-1380
Author(s):  
Jong Yun Jang ◽  
Chong Sun Lee ◽  
Chang Min Suh
Keyword(s):  
Cerebrospinal Fluid ◽  
Numerical Simulations ◽  
Optimum Design ◽  
Upright Position ◽  
Design Parameters ◽  
Design Variables

The present study investigated design parameters of an anti-siphon device used with shunt valves to treat patients with hydrocephalus. Structural analyses were performed to understand roles of design variables and optimize performance of the diaphragm-type anti-siphon device (hereafter referred to as the ASD). Experiments were performed on the lab-made product and showed good agreements with the numerical simulations. Using the simulations, we were able to design a more physiological ASD which gave equal opening pressures in both supine and upright postures. Tissue encapsulization phenomenon was also simulated and the results indicated underdrainage of CSF in the upright position of the patient.

Parametric Aircraft Design Optimisation Study Using Span and Mean Chord as Main Design Drivers

2014 ◽  
Vol 1016 ◽  
pp. 365-369 ◽  
Author(s):  
Pedro Albuquerque ◽  
Pedro Gamboa ◽  
Miguel Silvestre
Keyword(s):  
Design Methodology ◽  
Aircraft Design ◽  
Design Parameters ◽  
Flight Performance ◽  
Air Cargo ◽  
Main Design ◽  
Design Specifications ◽  
Performance Requirements ◽  
Aircraft Performance

The present work describes an aircraft design methodology that uses the wingspan and its mean aerodynamic chord as main design parameters. In the implemented tool, low fidelity models have been developed for the aerodynamics, stability, propulsion, weight, balance and flight performance. A Fortran® routine that calculates the aircraft performance for the user defined mission and vehicle’s performance requirements has been developed. In order to demonstrate this methodology, the results for a case study using the design specifications of the Air Cargo Challenge 2013 are shown.

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