Robust Design of Gears

1998 ◽  
Author(s):  
Richard E. Dippery ◽  
Raghu Echempati
Keyword(s):  
Robust Design ◽  
Gear System ◽  
Design Parameters ◽  
Mechanical Components

Abstract The terms “Robust Design” or sensitivity of a design to variance of design parameters is gaining importance in design of mechanical components and structures. This paper has been written as the result of an introductory investigation to determine the applicability of robust design for a given gear system and development of a model to perform the evaluations. Work has been performed based upon evaluation of a design being performed using AGMA standards.

An approach of robust reliability design for mechanical components

2005 ◽  
Vol 219 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Y M Zhang ◽  
X D He ◽  
Q L Liu ◽  
B C Wen
Keyword(s):  
Robust Design ◽  
Design Method ◽  
Random Variables ◽  
Design Parameters ◽  
Theoretical Formula ◽  
Reliability Design ◽  
Reliability Sensitivity ◽  
Mechanical Components ◽  
Reliability Based Optimization ◽  
Robust Reliability

The reliability-based optimization, the reliability sensitivity technique, and the robust design are employed to present a practical and effective approach of robust reliability design for mechanical components on the condition of known probabilistic characteristics of original random variables. The theoretical formula of robust reliability design for mechanical components is obtained. The respective program can be used to obtain the robust reliability design parameters accurately and quickly. According to the numerical results, the method proposed is a convenient and practical robust reliability design method.

Robust Compressor Blades for Desensitizing Operational Tip Clearance Variations

2014 ◽  
Author(s):  
Pranay Seshadri ◽  
Shahrokh Shahpar ◽  
Geoffrey T. Parks
Keyword(s):  
Robust Design ◽  
Total Pressure ◽  
Pressure Rise ◽  
Side Surface ◽  
Tip Clearance ◽  
Design Parameters ◽  
Compressor Blades ◽  
Robust Designs ◽  
Multi Objective ◽  
Mean And Variance

Robust design is a multi-objective optimization framework for obtaining designs that perform favorably under uncertainty. In this paper robust design is used to redesign a highly loaded, transonic rotor blade with a desensitized tip clearance. The tip gap is initially assumed to be uncertain from 0.5 to 0.85% span, and characterized by a beta distribution. This uncertainty is then fed to a multi-objective optimizer and iterated upon. For each iteration of the optimizer, 3D-RANS computations for two different tip gaps are carried out. Once the simulations are complete, stochastic collocation is used to generate mean and variance in efficiency values, which form the two optimization objectives. Two such robust design studies are carried out: one using 3D blade engineering design parameters (axial sweep, tangential lean, re-cambering and skew) and the other utilizing suction and pressure side surface perturbations (with bumps). A design is selected from each Pareto front. These designs are robust: they exhibit a greater mean efficiency and lower variance in efficiency compared to the datum blade. Both robust designs were also observed to have significantly higher aft and reduced fore tip loading. This resulted in a weaker clearance vortex, wall jet and double leakage flow, all of which lead to reduced mixed-out losses. Interestingly, the robust designs did not show an increase in total pressure at the tip. It is believed that this is due to a trade-off between fore-loading the tip and obtaining a favorable total pressure rise and higher mixed-out losses, or aft-loading the tip, obtaining a lower pressure rise and lower mixed-out losses.

scholarly journals Early Robust Design—Its Effect on Parameter and Tolerance Optimization

2021 ◽  
Vol 11 (20) ◽  
pp. 9407
Author(s):  
Stefan Goetz ◽  
Martin Roth ◽  
Benjamin Schleich
Keyword(s):  
Product Development ◽  
Robust Design ◽  
Product Development Process ◽  
Design Parameters ◽  
Concept Design ◽  
Design Decisions ◽  
Dynamic Markets ◽  
Tolerance Optimization ◽  
Qualitative Approaches ◽  
Design Activities

The development of complex products with high quality in dynamic markets requires appropriate robust design and tolerancing workflows supporting the entire product development process. Despite the large number of methods and tools available for designers and tolerance engineers, there are hardly any consistent approaches that are applicable throughout all development stages. This is mainly due to the break between the primarily qualitative approaches for the concept stage and the quantitative parameter and tolerance design activities in subsequent stages. Motivated by this, this paper bridges the gap between these two different views by contrasting the used terminology and methods. Moreover, it studies the effects of early robust design decisions with a focus on Suh’s Axiomatic Design axioms on later parameter and tolerance optimization. Since most robust design activities in concept design can be ascribed to these axioms, this allows reliable statements about the specific benefits of early robust design decisions on the entire process considering variation in product development for the first time. The presented effects on the optimization of nominal design parameters and their tolerance values are shown by means of a case study based on ski bindings.

scholarly journals Robust optimization design of structures based on the specular reflection algorithm

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983413
Author(s):  
Qisong Qi ◽  
Qing Dong ◽  
Yunsheng Xin
Keyword(s):  
Robust Design ◽  
Structural Design ◽  
Optimization Design ◽  
Design Method ◽  
Specular Reflection ◽  
Design Parameters ◽  
Theoretical Design ◽  
Recent Advancement ◽  
Robust Optimization Design ◽  
Robust Design Method

The nominal values of structural design parameters are usually calculated using a traditional deterministic optimization design method. However, owing to the failure of this type of method to consider potential variations in design parameters, the theoretical design results can be far from reality. To address this problem, the specular reflection algorithm, a recent advancement in intelligence optimization, is used in conjunction with a robust design method based on sensitivity. This method not only is able to fully consider the influence of parameter uncertainty on the design results but also has strong applicability. The effectiveness of the proposed method is verified by numerical examples, and the results show that the robust design method can significantly improve the reliability of the structure.

Carbon Powder as Additive in Near-Net-Shaping of Mechanical Components through Warm Forming Route

2013 ◽  
Vol 594-595 ◽  
pp. 948-952
Author(s):  
Mujibur M. Rahman ◽  
N.A.A.A. Kadir
Keyword(s):  
Carbon Content ◽  
Density Measurement ◽  
Warm Forming ◽  
Design Parameters ◽  
Carbon Powder ◽  
Forming Temperature ◽  
Die Compaction ◽  
Mechanical Components ◽  
Near Net Shaping ◽  
Net Shaping

This paper presents the study of carbon powder as additive in near-net-shaping of mechanical components through warm forming route. Three design parameters, i.e., carbon content (wt %), forming temperature, and sintering schedule were investigated. Iron powder ASC 100.29 was mechanically mixed with different wt% of carbon and copper powder for 30 minutes to prepare the feedstock. Green compacts were then formed through uni-axial die compaction process at 30°C and 180oC. The defect-free green compacts were then sintered at 1000oC in an argon gas fired furnace at a heating/cooling rate of 5oC/minute for 30, 60, and 90 minutes, respectively. The green samples as well the sintered products were characterized through relative density measurement, radial shrinkage, and microstructure evaluation. The results revealed that excessive carbon content contributed adverse effect to the final quality of the products.

The Effect of Different Optimization Methods on Robustness for Robust Optimization Design

2014 ◽  
Vol 721 ◽  
pp. 464-467
Author(s):  
Tao Fu ◽  
Qin Zhong Gong ◽  
Da Zhen Wang
Keyword(s):  
Robust Optimization ◽  
Objective Function ◽  
Robust Design ◽  
Optimization Design ◽  
Optimization Methods ◽  
Optimization Method ◽  
Design Parameters ◽  
Hybrid Particle Swarm Optimization ◽  
Design Variables ◽  
Robust Optimization Design

In view of robustness of objective function and constraints in robust design, the method of maximum variation analysis is adopted to improve the robust design. In this method, firstly, we analyses the effect of uncertain factors in design variables and design parameters on the objective function and constraints, then calculate maximum variations of objective function and constraints. A two-level optimum mathematical model is constructed by adding the maximum variations to the original constraints. Different solving methods are used to solve the model to study the influence to robustness. As a demonstration, we apply our robust optimization method to an engineering example, the design of a machine tool spindle. The results show that, compared with other methods, this method of HPSO(hybrid particle swarm optimization) algorithm is superior on solving efficiency and solving results, and the constraint robustness and the objective robustness completely satisfy the requirement, revealing that excellent solving method can improve robustness.

Multidisciplinary Integration and Robustness Evaluation Applied to Low Pressure Turbine Casing Design

2006 ◽  
Author(s):  
Gian Paolo De Poli ◽  
Carlo Frola ◽  
Massimo Gallizio ◽  
Luca Fattore ◽  
Massimiliano Mattone
Keyword(s):  
Robust Design ◽  
Monte Carlo Analysis ◽  
Design Parameters ◽  
Property Variation ◽  
Low Pressure Turbine ◽  
Turbine Casing ◽  
Reliability Methods ◽  
Critical Location ◽  
And Performance ◽  
Geometrical Dimensions

In modern aerospace engineering design context one of the most important task is managing and simulate properly the effect of uncertainties on the response and performance of the system. In fact real engineering problems are characterised by random variations of material property, variation of loading conditions, manufacturing tolerances, etc. Different approaches have been developed by the research community to address uncertainties; while reliability methods primarily deal with probability of constraint satisfaction or violation, robust design methods have focused on the variation of system responses due to design parameters random variation. In this paper a robust design (RD) analysis of gas-turbine casing is performed in order to estimate how much uncertainties affect the life of the component. The RD analysis is performed in a multidisciplinary environment since the casing is subjected to thermo-mechanical loads. First thermal steady-state analysis has been performed changing randomly the boundary conditions (heat transfer coefficient and air temperature) and the temperature distribution on the casing is calculated. Then the structural analysis is performed changing geometrical dimensions on the base of defined tolerances and process capability. The result of the Monte Carlo analysis is a statistic distribution of the stress in the critical locations. This information is used to estimate the statistic distribution of the life in each critical location. The obtained result consents to evaluate the risk that some critical location exceeds the life margin limit.

Stability Based Robust Eigenvalue Design for Tolerance

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
XinJiang Lu ◽  
Han-Xiong Li
Keyword(s):  
Robust Design ◽  
Design Method ◽  
Integrated Approach ◽  
System Stability ◽  
Design Parameters ◽  
Complex Eigenvalue ◽  
Sensitivity Matrix ◽  
Eigenvalue Sensitivity ◽  
Design Systems ◽  
Robust Design Method

A novel integrated approach is developed to design systems for stability and robustness. First, design parameters with large variation bounds are chosen to maintain system stability. Then, a robust eigenvalue design problem is considered to make the dynamic response less sensitive to parameter variations. A new complex sensitivity matrix is derived from the system dynamics with the eigenvalue variation approximated into a first-order model by means of the eigenvector orthogonal theory. Through a proper transformation, the complex eigenvalue sensitivity of the Jacobian matrix can still be processed by the traditional robust design approach. By minimizing the eigenvalue sensitivity, design parameters can be obtained for stability as well as robustness. Furthermore, the tolerance space of the selected parameters can be maximized to improve robust performance. A Laval rotor example is used to demonstrate the effectiveness of the proposed robust design method.

Optimization Design on Dynamic Reliability of a Tension Bar

2011 ◽  
Vol 415-417 ◽  
pp. 807-812
Author(s):  
Xin Gang Wang ◽  
Bao Yan Wang ◽  
Xiu Feng Tan
Keyword(s):  
Optimization Design ◽  
Theoretical Data ◽  
Computational Method ◽  
Design Parameters ◽  
Arbitrary Distribution ◽  
Random Load ◽  
Reliability Design ◽  
Dynamic Reliability ◽  
Reliability Sensitivity ◽  
Mechanical Components

This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The variation rules of strength, load, and reliability of mechanical components are studied with a change in time, and a model is established for dynamic reliability of mechanical components under the random load acting. By combining the theory of reliability design with the method of sensitivity analysis, the computational method of dynamic reliability sensitivity design with arbitrary distribution parameter is proposed based on the methods Edgeworth and perturbation, and the problem of dynamic reliability sensitivity design of mechanical components distributed arbitrary distribution is solved as well as the variation rules of dynamic reliability sensitivity are given. The variation of reliability is studied as design parameters change a little, which provides theoretical data for dynamic reliability design of mechanical components.

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