Sensitivity analysis and Taguchi optimization procedure for a single-shoe drum brake

2019 ◽  
Vol 233 (10) ◽  
pp. 3690-3698 ◽  
Author(s):  
Salwan Obaid Waheed Khafaji ◽  
Noah Manring
Keyword(s):  
Numerical Models ◽  
Low Cost ◽  
Optimization Procedure ◽  
Taylor Series Expansion ◽  
Design Parameters ◽  
Taguchi Optimization ◽  
Form Analysis ◽  
Drum Brake ◽  
Braking Torque ◽  
Drum Brakes

Drum brakes have dominated the braking industry for many years and will most likely continue to do so for the foreseeable future due to their low cost and adequate operating performance. Basic equations for conventional brake are presented, while complicated analysis has been published using finite element methods to predict brake squeal and instability. This paper seeks to step away from the complexity of numerical models to consider the fundamental braking phenomenon of a single-shoe drum brake, using nondimensional, closed-form analysis and a Taylor series expansion to examine the effects of perturbing dimensionless design parameters. In addition, an optimal design for the conventional brake is achieved using Taguchi method. In conclusion, this paper shows that the braking torque is dependent upon only four dimensionless groups, and that two of these groups dominate the physics of braking. Furthermore, it is shown that adjustments to these two dominating groups have a direct impact on the contact pressure between that shoe material and the brake drum, and that this pressure must be kept below the yield strength of the braking material in order to prevent a mechanical failure of the brake. Since the results are nondimensional, they are generally applicable to all single-shoe drum brakes having a design with mechanical features that are similar to the one analyzed in this paper. There is very good agreement between the results of both Taguchi and sensitivity regarding the significance and insignificance of the design parameters.

Optimal Design of a Conventional and Magnetorheological Fluid Brakes Using Sensitivity Analysis and Taguchi Method

2018 ◽  
Author(s):  
Salwan Obaid Waheed Khafaji ◽  
Noah D. Manring ◽  
Mohammed Al-Mudhafar
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Series Expansion ◽  
Numerical Models ◽  
Taylor Series Expansion ◽  
Magnetorheological Fluid ◽  
Design Parameters ◽  
Taguchi Approach ◽  
Dimensionless Groups ◽  
Braking Torque

Drum brakes have dominated the braking industry for many years due to their low cost and adequate operating performance. In this paper, the authors present the first example of studying the sensitivity analysis of a magnetorheological fluid (MRF) and a conventional frictional brake by using first order Tayler series expansion. Nondimensional analyses are carried out to generalize the analyses for every brake configuration. This paper seeks to step away from the complexity of the numerical models for these brakes. Taylor series expansion is used to examine the effects of perturbing dimensionless design parameters on the braking torque. In addition, Taguchi approach is applied for the brakes to study the contribution of the design parameters on the braking torque and to obtain the optimal design. It is shown in this paper that braking torque for magnetorheological fluid brake is dependent on seven dimensionless groups while the frictional brake is dependent upon only four dimensionless groups. Four groups of the MRF brake and two groups for the frictional brake dominate the physics of braking. The sensitivity analysis has identified the key parameters that must be adjusted in order to increase braking torque. Furthermore, Taguchi approach has showed the how the variations of input variables affect the variations of the output variable and stated the optimal levels of the design parameters that achieve the optimal design.

Development of Control Strategies for Interconnected Pneumatic Wave Energy Converters

2017 ◽  
Author(s):  
Eric Thacher ◽  
Helen Bailey ◽  
Bryson Robertson ◽  
Scott Beatty ◽  
Jason Goldsworthy ◽  
...  
Keyword(s):  
Wave Energy ◽  
Time Domain ◽  
Power Output ◽  
Numerical Models ◽  
Control Strategies ◽  
Low Cost ◽  
Optimization Procedure ◽  
Wave Energy Converter ◽  
Energy Converter ◽  
Sea State

In the field of wave energy converter control, high fidelity numerical models have become the predominant tool for the development of accurate and comprehensive control strategies. In this study, a numerical model of a novel wave energy converter, employing a pneumatic power take-off, is created to provide a low-cost method for the development of a power-maximizing control strategy. Device components and associated architectures are developed in the time domain solvers Proteus DS and MATLAB/Simulink. These two codes are dynamically coupled at run time to produce a complete six degree of freedom, time domain simulation of the converter. Utilizing this numerical framework, a genetic algorithm optimization procedure is implemented to optimally select eight independent parameters governing the PTO geometry. Optimality is measured in terms of estimated annual energy production at a specific deployment location off the West Coast of Canada. The optimization exercise is one layer of PTO force control — the parameters selected are seen to provide significant improvements in the annual power output, while also smoothing the WEC power output on both a sea-state by sea-state and wave-by-wave basis.

IoT based e-Healthcare System to Enable Remote Patient Care based on Cloud Server

2017 ◽  
Vol 7 (7) ◽  
pp. 36
Author(s):  
P.Venu Gopala Rao ◽  
Eslavath Raja ◽  
Ramakrishna Gandi ◽  
G. Ravi Kumar
Keyword(s):  
Low Cost ◽  
Vital Signs ◽  
Smart Phone ◽  
Medical Professional ◽  
Design Parameters ◽  
Cloud Server ◽  
Significant Area ◽  
Efficient Data ◽  
System Data ◽  
Remote Patient

IoT (Internet of Things) has become most significant area of research to design an efficient data enabled services with the help of sensors. In this paper, a low-cost system design for e-healthcare service to process the sensitive health data is presented. Vital signs of the human body are measured from the patient location and shared with a registered medical professional for consultation. Temperature and heart rate are the major signals obtained from a patient for the initial build of the system. Data is sent to a cloud server where processing and analysis is provided for the medical professional to analyze. Secure transmission and dissemination of data through the cloud server is provided with an authentication system and the patient could be able to track his data through a smart phone on connecting to the cloud server. A prototype of the system along with its design parameters has been discussed.

Modeling drive wheels of hoisting machines with rubber cables

2020 ◽  
pp. 105-114
Author(s):  
V. E. Perekutnev ◽  
V. V. Zotov
Keyword(s):  
Stress State ◽  
Safety Factor ◽  
Numerical Models ◽  
Design Parameters ◽  
Potential Range ◽  
Capital Costs ◽  
Reducing Gear ◽  
Reduce Risk ◽  
Steel Cables ◽  
Sidewall Surface

Upgrading of hoisting machines aims to improve their performance, to reduce risk of accidents, and to cut down operational and capital costs. One of the redesign solutions is replacement of steel cables by rubber cables. This novation can extend life of pulling members, decrease diameters of drive and guide wheels and, consequently, elements of the whole hoisting machines: rotor, reducing gear, motor. This engineering novation needs re-designing of hoisting machines; thus, the new design should be validated, in particular, strength characteristics of the machine members. This article considers a drive wheel of a hoisting machine with a pulling belt. In order to justify the potential range of design parameters with regard to safety factor, the numerical models of different-design drive wheels are developed and their operation with pulling belt (rubber cable) is simulated in the SolidWorks environment. The data on the stress state of the wheel elements are analyzed, the most loaded points are identified, and the maximal stresses on the sidewall surface and in the spokes of wheels of different designs are plotted.

scholarly journals An Alternative Statistical Model for Predicting Salinity Variations in Estuaries

2020 ◽  
Vol 12 (24) ◽  
pp. 10677
Author(s):  
Ronghui Ye ◽  
Jun Kong ◽  
Chengji Shen ◽  
Jinming Zhang ◽  
Weisheng Zhang
Keyword(s):  
Statistical Model ◽  
River Discharge ◽  
Numerical Models ◽  
Low Cost ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Large River ◽  
Physical Models ◽  
Long Term Effects ◽  
Salinity Variations

Accurate salinity prediction can support the decision-making of water resources management to mitigate the threat of insufficient freshwater supply in densely populated estuaries. Statistical methods are low-cost and less time-consuming compared with numerical models and physical models for predicting estuarine salinity variations. This study proposes an alternative statistical model that can more accurately predict the salinity series in estuaries. The model incorporates an autoregressive model to characterize the memory effect of salinity and includes the changes in salinity driven by river discharge and tides. Furthermore, the Gamma distribution function was introduced to correct the hysteresis effects of river discharge, tides and salinity. Based on fixed corrections of long-term effects, dynamic corrections of short-term effects were added to weaken the hysteresis effects. Real-world model application to the Pearl River Estuary obtained satisfactory agreement between predicted and measured salinity peaks, indicating the accuracy of salinity forecasting. Cross-validation and weekly salinity prediction under small, medium and large river discharges were also conducted to further test the reliability of the model. The statistical model provides a good reference for predicting salinity variations in estuaries.

Experimental Investigation and Analysis on Dynamic Strain of Leading Trailing Shoe Drum Brake

2017 ◽  
Author(s):  
Xiaoying Wang ◽  
Zijie Fan ◽  
Jia Li ◽  
LiangJin Gui
Keyword(s):  
Optimization Design ◽  
Test Procedure ◽  
Mechanical Analysis ◽  
Dynamic Strain ◽  
Wireless Data ◽  
Drum Brake ◽  
Wireless Data Acquisition ◽  
Drum Brakes ◽  
Temperature Strain ◽  
Temperature Time

The research on the dynamic strain of drum brakes is of great significance in performance evaluation, structure optimization and fatigue prediction. Based on current research of strain experiments and measuring technology, a new test procedure is proposed to investigate strain and temperature information of a working drum. Wireless data acquisition system and high-temperature strain gauges are applied. The strain-time and temperature-time curves are studied on the conditions of emergency brake and continuous brake. A tribological and thermo-mechanical analysis are conducted by using software ABAQUS. Results show that the strain is uneven when the drum contacts different zones of friction plates. Seasonal variation is another feature and a set of four wave crests repeats during the rotation. Meanwhile, thermal effect is proved important to strain. The simulation results coincide well with experiments, proving that this method provides a practical way to verify the calculation. The study also lays the foundation for the following fatigue analysis and optimization design.

Optimization of Turbofan Propulsion Cycle Using a Genetic Algorithm

2010 ◽  
Author(s):  
Adel Ghenaiet
Keyword(s):  
Genetic Algorithm ◽  
Fuel Consumption ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Optimization Procedure ◽  
Specific Fuel Consumption ◽  
High Mass ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Simplifying Assumptions

This paper presents an evolutionary approach as the optimization framework to design for the optimal performance of a high-bypass unmixed turbofan to match with the power requirements of a commercial aircraft. The parametric analysis had the objective to highlight the effects of the principal design parameters on the propulsive performance in terms of specific fuel consumption and specific thrust. The design optimization procedure based on the genetic algorithm PIKAIA coupled to the developed engine performance analyzer (on-design and off-design) aimed at finding the propulsion cycle parameters minimizing the specific fuel consumption, while meeting the required thrusts in cruise and takeoff and the restrictions of temperatures limits, engine size and weight as well as pollutants emissions. This methodology does not use engine components’ maps and operates on simplifying assumptions which are satisfying the conceptual or early design stages. The predefined requirements and design constraints have resulted in an engine with high mass flow rate, bypass ratio and overall pressure ratio and a moderate turbine inlet temperature. In general, the optimized engine is fairly comparable with available engines of equivalent power range.

scholarly journals Artificial neural networks for inverse design of resonant nanophotonic components with oscillatory loss landscapes

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 385-392
Author(s):  
Joeri Lenaerts ◽  
Hannah Pinson ◽  
Vincent Ginis
Keyword(s):  
Machine Learning ◽  
Optimization Procedure ◽  
Linear Mapping ◽  
Inverse Design ◽  
Design Parameters ◽  
Second Step ◽  
Input Parameters ◽  
Novel Variant ◽  
Resonant Systems ◽  
The Fourier Transform

AbstractMachine learning offers the potential to revolutionize the inverse design of complex nanophotonic components. Here, we propose a novel variant of this formalism specifically suited for the design of resonant nanophotonic components. Typically, the first step of an inverse design process based on machine learning is training a neural network to approximate the non-linear mapping from a set of input parameters to a given optical system’s features. The second step starts from the desired features, e.g. a transmission spectrum, and propagates back through the trained network to find the optimal input parameters. For resonant systems, this second step corresponds to a gradient descent in a highly oscillatory loss landscape. As a result, the algorithm often converges into a local minimum. We significantly improve this method’s efficiency by adding the Fourier transform of the desired spectrum to the optimization procedure. We demonstrate our method by retrieving the optimal design parameters for desired transmission and reflection spectra of Fabry–Pérot resonators and Bragg reflectors, two canonical optical components whose functionality is based on wave interference. Our results can be extended to the optimization of more complex nanophotonic components interacting with structured incident fields.

Kinetostatic backflip strategy for self-recovery of quadruped robots with the selected rotation axis

Robotica ◽  
2021 ◽  
pp. 1-19
Author(s):  
Shengjie Wang ◽  
Kun Wang ◽  
Chunsong Zhang ◽  
Jian S Dai
Keyword(s):  
Optimal Design ◽  
Energy Analysis ◽  
Rotation Axis ◽  
Low Cost ◽  
Minimum Energy ◽  
Design Parameters ◽  
Quadruped Robots ◽  
Design Idea ◽  
The Relationship

Abstract A kinetostatic approach applied to the design of a backflip strategy for quadruped robots is proposed in this paper. Inspired by legged animals and taking the advantage of the leg workspace, this strategy provides an optimal design idea for the low-cost quadruped robots to achieve self-recovery after overturning. Through kinetostatic and energy analysis, a four-stepped backflip strategy based on the selected rotation axis with minimum energy is proposed, with a process of selection, lifting, rotating, and protection. The kinematic factors that affect the backflip are investigated, along with the relationship between the design parameters of the leg and trunk being analyzed. At the end of this paper, the strategy is validated by a simulation and experiments with a prototype called DRbot, demonstrating that the strategy endows the robot a strong self-recovery ability in various terrains.

scholarly journals Thermal-Structural Design of Actively-Cooled Panels Reinforced by Light-Weight Truss Cores

2013 ◽  
Author(s):  
Hongwei Song ◽  
Mingjun Li ◽  
Chenguang Huang ◽  
Xi Wang
Keyword(s):  
Heat Transfer ◽  
Structural Analysis ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Thermal Environment ◽  
Numerical Models ◽  
Lightweight Design ◽  
Optimization Procedure ◽  
Combustion Gas ◽  
Design Variables

This paper focuses on thermal-structural analysis and lightweight design of actively-cooled panels reinforced by low density lattice-framed material (LFM) truss cores. Numerical models for actively-cooled panels are built up with parametric codes to perform the coupled thermal-structural analysis, considering the internal thermal environment of convective heat transfer in the combustor and convective heat transfer in the cooling channel, and internal pressures from the combustion gas and the coolant. A preliminary comparison of the LFM truss reinforced actively-cooled panel and the non-reinforced panel demonstrates that the thermal-structural behavior is significantly improved. Then, an optimization procedure is carried out to find the lightest design while satisfying thermal deformation and plastic strain constraints, with thicknesses of face sheets and topology parameters of LFM truss as design variables. The optimization result demonstrates that, compared with the non-reinforced actively-cooled panels, weight reduction for the panel reinforced by LFM truss may reach 19.6%. We have also fabricated this type of actively-cooled panel in the laboratory level, and the specimen shows good mechanical behaviors.

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