Development of femoral component design geometry by using DMROVAS (design method requiring optimum volume and safety)

2019 ◽  
Vol 37 (2) ◽  
pp. 682-704 ◽  
Author(s):  
Burak Öztürk ◽  
Fehmi Erzincanli
Keyword(s):  
Optimal Design ◽  
Femoral Component ◽  
Safety Factor ◽  
Maximum Stress ◽  
Design Method ◽  
Design Parameters ◽  
Average Weight ◽  
Universal Method ◽  
Content Type ◽  
Optimum Volume

Purpose This study aims to design a femoral component with minimum volume and maximum safety coefficient. Total knee prosthesis is a well-established therapy in arthroplasty applications. And in particular, with respect to damaged or weakened cartilage, new prostheses are being manufactured from bio-materials which are compatible with the human body to replace these damages. A new universal method (design method requiring optimum volume and safety [DMROVAS]) was propounded to find the optimum design parameters of tibial component. Design/methodology/approach The design montage was analyzed via the finite element method (FEM). To ensure the stability of the prosthesis, the maximum stress angle and magnitude of the force on the knee were taken into consideration. In the analysis process, results revealed two different maximum stress areas which were supported by case reports in the literature. Variations of maximum stress, safety factor and weight were revealed by FEM analysis, and ANOVA was used to determine the F force percentage for each of the design parameters. Findings Optimal design parameter levels were chosen for the individual’s minimum weight. Stress maps were constructed to optimize design choices that enabled further enhancement of the design models. The safety factor variation (SFV) of 5.73 was obtained for the volume of 39,219 mL for a region which had maximum stress. At the same time, for a maximum SFV and at the same time an average weight, values of 37,308 mL and 5.8 for volume and SFV were attained, respectively, using statistical methods. Originality/value This proposed optimal design development method is new and one that can be used for many biomechanical products and universal industrial designs.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

Theoretical and Experimental Investigation of an Externally Pressurized Porous Annular Thrust Gas Bearing and Its Optimal Design

1997 ◽  
Vol 119 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Changzhi Cui ◽  
Kyosuke Ono
Keyword(s):  
Experimental Investigation ◽  
Surface Layer ◽  
Optimal Design ◽  
Design Method ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
The Body ◽  
Design Parameters ◽  
Darcy Model ◽  
Gas Bearing

Static and dynamic characteristics of an externally pressurized porous annular thrust gas bearing (PATGB), which has a thin restricted surface layer, are investigated by numerical analysis and experiment. In the analysis, it is assumed that the fluid flow obeys Darcy’s law in the porous material, restricted with Darcy’s restrictor (Darcy-Darcy model) or orifice restrictor (Darcy-Orifice model) in the surface layer. From experimental investigation, it is found that the theoretical results calculated by the Darcy-Darcy model agree with the experimental data better than those of the Darcy-Orifice model. Based on the Darcy-Darcy model, the unique relationships among the design parameters, which can provide the maximum damping ratio, were derived as functions of feeding parameter under the conditions of allowable static stiffness and the local minimum dynamic stiffness. Considering the dimensionless mass of the body supported by the bearing, an optimal design method is proposed to maximize the damping ratio at the natural frequency, while maintaining the required stiffness in the low frequency region.

An Optimal Design Method for Artificial Neural Networks by Using the Design of Experiments

2007 ◽  
Vol 11 (6) ◽  
pp. 593-599 ◽  
Author(s):  
Eiichi Inohira ◽  
◽  
Hirokazu Yokoi
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Optimal Design ◽  
Design Method ◽  
Feedforward Neural Networks ◽  
Learning Rate ◽  
Design Parameters ◽  
Approximation Accuracy ◽  
Artificial Neural ◽  
Trained Neural Network

This paper presents a method to optimally design artificial neural networks with many design parameters using the Design of Experiment (DOE), whose features are efficient experiments using an orthogonal array and quantitative analysis by analysis of variance. Neural networks can approximate arbitrary nonlinear functions. The accuracy of a trained neural network at a certain number of learning cycles depends on both weights and biases and its structure and learning rate. Design methods such as trial-and-error, brute-force approaches, network construction, and pruning, cannot deal with many design parameters such as the number of elements in a layer and a learning rate. Our design method realizes efficient optimization using DOE, and obtains confidence of optimal design through statistical analysis even though trained neural networks very due to randomness in initial weights. We apply our design method three-layer and five-layer feedforward neural networks in a preliminary study and show that approximation accuracy of multilayer neural networks is increased by picking up many more parameters.

A generative design approach for modular construction in congested urban areas

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuxi Wei ◽  
Hyungjoo Choi ◽  
Zhen Lei
Keyword(s):  
Urban Areas ◽  
Design Method ◽  
Residential Building ◽  
Information Modeling ◽  
Design Approach ◽  
Design Parameters ◽  
Building Structures ◽  
Modular Construction ◽  
Generative Design ◽  
Content Type

PurposeModular construction is widely adopted and used in the construction industry to improve construction performance with respect to both efficiency and productivity. The evaluation of design options for modular construction can be iterative, and thus automation is required to develop design alternatives. This research aims to explore the potential of utilizing the generative design approach to automate modular construction for residential building structures in urban areas such as New York City.Design/methodology/approachThe proposed research methodology is investigated for a systematic approach to parametrize design parameters for modular construction layout design as well as incorporate design rules/parameters into modularizing design layouts in a Building Information Modeling (BIM) environment. Based on current building codes and necessary inputs by the user, the proposed approach enables providing recommendations in a generative design method and optimizes construction processes by performing analytical calculations.FindingsThe generative design has been found to be efficient in generating layout designs for modular construction based on parametric design. The integration of BIM and generative design can allow industry practitioners to fast generate design layout with evaluations from constructability perspectives.Originality/valueThis paper has proposed a new approach of incorporating generative design with BIM technologies to solve module layout generations by considering design and constructability constraints. The method can be further extended for evaluating modular construction design from manufacturability and assembly perspectives.

Personalized femoral component design and its direct manufacturing by selective laser melting

2016 ◽  
Vol 22 (2) ◽  
pp. 330-337 ◽  
Author(s):  
Changhui Song ◽  
Yongqiang Yang ◽  
Yunda Wang ◽  
Jia-kuo Yu ◽  
Di Wang
Keyword(s):  
Corrosion Resistance ◽  
Selective Laser Melting ◽  
Femoral Component ◽  
Computer Aided Design ◽  
Design Method ◽  
Laser Melting ◽  
Content Type ◽  
Computer Aided ◽  
Biological Corrosion ◽  
Aided Design

Purpose This paper aims to achieve rapid design and manufacturing of personalized total knee femoral component. Design/methodology/approach On the basis of a patient’s bone model, a matching personalized knee femoral component was rapidly designed with the help of computer-aided design method, then manufactured directly and rapidly by selective laser melting (SLM). Considered SLM as manufacturing technology, CoCrMo-alloyed powder that meets ASTM F75 standard is made of femoral component under optimal processing parameters. The feasibility of SLM forming through conducting experimental test of mechanical properties, surface roughness, biological corrosion resistance was analyzed. Findings The result showed that the tensile strength, yield strength, hardness and biological corrosion resistance of CoCrMo-alloyed personalized femoral component fulfill knee joint prosthesis standard through post-processing. Originality/value Traditional standardized prosthesis implantation manufacturing approach was changed by computer-aided design and personalized SLM direct manufacturing, and provided a new way for personalized implanted prosthesis to response manufacturing rapidly.

Hierarchical paradigm for automated optimal design of dual-band wearable antenna with simplified human body models

2018 ◽  
Vol 37 (5) ◽  
pp. 1597-1608 ◽  
Author(s):  
Lukasz Januszkiewicz ◽  
Paolo Di Barba ◽  
Slawomir Hausman
Keyword(s):  
Optimal Design ◽  
Human Body ◽  
Automated Design ◽  
Dual Band ◽  
Design Parameters ◽  
Hierarchical Approach ◽  
Human Body Model ◽  
Content Type ◽  
Body Model ◽  
Wearable Antennas

Purpose The purpose of this study is to develop a method to reduce the computation time necessary for the automated optimal design of dual-band wearable antennas. In particular, the authors investigated if this can be achieved by the use of a hierarchical optimization paradigm combined with a simplified human body model. The geometry of the antenna under consideration is described via eight geometrical parameters which are automatically adjusted with the use of an evolutionary algorithm to improve the impedance matching of an antenna located in the proximity of a human body. Specifically, the antennas were designed to operate in the ISM band which covers two frequency ranges: 2.4-2.5 GHz and 5.7-5.9 GHz. Design/methodology/approach During the studies on the automated design of wearable antennas using evolutionary computing, the authors observed that not all design parameters exhibit equal influence on the objective function. Therefore, it was hypothesized that to reduce the computation effort, the design parameters can be activated sequentially based on their influence. Accordingly, the authors’ computer code has been modified to include this feature. Findings The authors’ novel hierarchical multi-parameter optimization method was able to converge to a better solution within a shorter time compared to an equivalent method not exploiting automatic activation of an increasing number of design parameters. Considering a significant computational cost involved in the calculation of the objective function, this exhibits a convincing advantage of their hierarchical approach, at least for the considered class of antennas. Research limitations/implications The described method has been developed for the design of single- or dual-band wearable antennas. Its application to other classes of antennas and antenna environments may require some adjustments of the objective functions or parameter values of the evolutionary algorithm. It follows from the well-recognized fact that all optimization methods are to some extent application-specific. Practical implications Computation load involved in the automated design and optimization can be significantly reduced compared to the non-hierarchical approach with a heterogeneous human body model. Originality/value To the best of the authors’ knowledge, the described application of hierarchical paradigm to the optimization of wearable antennas is fully original, as well as is its combination with simplified body models.

Simulation-based search for optimal designs of accelerated life tests through response surface methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Daniel Ayasse ◽  
Kangwon Seo
Keyword(s):  
Response Surface Methodology ◽  
Optimal Design ◽  
Objective Function ◽  
Response Surface ◽  
Failure Time ◽  
Simulated Data ◽  
Accelerated Life Test ◽  
Design Parameters ◽  
Content Type ◽  
Accelerated Life

PurposePlanning an accelerated life test (ALT) for a product is an important task for reliability practitioners. Traditional methods to create an optimal design of an ALT are often computationally burdensome and numerically difficult. In this paper, the authors introduce a practical method to find an optimal design of experiments for ALTs by using simulation and empirical model building.Design/methodology/approachInstead of developing the Fisher information matrix-based objective function and analytic optimization, the authors suggest “experiments for experiments” approach to create optimal planning. The authors generate simulated data to evaluate the quantity of interest, e.g. 10th percentile of failure time and apply the response surface methodology (RSM) to find an optimal solution with respect to the design parameters, e.g. test conditions and test unit allocations. The authors illustrate their approach applied to the thermal ALT with right censoring and lognormal failure time distribution.FindingsThe design found by the proposed approach shows substantially improved statistical performance in terms of the standard error of estimates of 10th percentile of failure time. In addition, the approach provides useful insights about the sensitivity of each decision variable to the objective function.Research limitations/implicationsMore comprehensive experiments might be needed to test its scalability of the method.Practical implicationsThis method is practically useful to find a reasonably efficient optimal ALT design. It can be applied to any quantities of interest and objective functions as long as those quantities can be computed from a set of simulated datasets.Originality/valueThis is a novel approach to create an optimal ALT design by using RSM and simulated data.

Application of topology optimization method for the gothic greenhouse design

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jalal Javadi Moghaddam ◽  
Davood Momeni ◽  
Ghasem Zarei
Keyword(s):  
Topology Optimization ◽  
Safety Factor ◽  
Structural Design ◽  
Volume Fraction ◽  
Design Method ◽  
Optimization Method ◽  
Content Type ◽  
Final Design ◽  
Structure Strength ◽  
Structural Compliance

Purpose This research presents a design method for designing greenhouse structures based on topology optimization. Moreover, the structural design of a gothic greenhouse is proposed in which its structural strength has been improved by using this proposed method. In this method, the design of the structure is done mathematically; therefore, in the design process, more attention can be focused on the constraint space and boundary conditions. It was also shown how the static reliability and fatigue coefficients will change as a result of the design of the greenhouse structure with this method. Another purpose of this study is to find the weakest part of the greenhouse structure against lateral winds and other general loads on the greenhouse structure. Design/methodology/approach In the proposed method, the outer surface and the allowable volume as a constraint domain were considered. The desired loads can be located on the constraint domain. The topology optimization was used to minimize the mass and structural compliance as the objective function. The obtained volume was modified for simplifying the construction. The changes in the shape of the greenhouse structure were investigated by choosing three different penalty numbers for the topology optimization algorithm. The final design of the proposed structure was performed based on the total simultaneous critical loads on the structure. The results of the proposed method were compared in the order of different volume fractions. This showed that the volume fraction approach can significantly reduce the weight of the structure while maintaining its strength and stability. Findings Topology optimization results showed different strut and chords composition because of the changes in maximum mass limit and volume fraction. The results showed that the fatigue was more hazardous, and it decreased the strength of structure nearly three times more than a static analysis. Further, it was noticed that how the penalty numbers can affect topology optimization results. An optimal design based on topology optimization results was presented to improve the proposed greenhouse design against destruction and demolition. Furthermore, this study shows the most sensitive part of the greenhouse against the standard loads of wind, snow, and crop. Originality/value The obtained designs were compared with a conventional arch greenhouse, and then the structural performances were shown based on standard loads. The results showed that in designing the proposed structure, the optimized changes increased the structure strength against the standard loads compared to a simple arch greenhouse. Moreover, the stress safety factor and fatigue safety factor because of different designs of this structure were also compared with each other.

Optimal design of spoke type motor and magnetizer using FEM and RSM

2018 ◽  
Vol 37 (2) ◽  
pp. 730-739
Author(s):  
Young Hyun Kim ◽  
Jung Ho Lee
Keyword(s):  
Optimal Design ◽  
Mass Production ◽  
Permanent Magnets ◽  
Design Method ◽  
Cost Effective ◽  
Torque Ripple ◽  
Efficient System ◽  
Cogging Torque ◽  
Content Type ◽  
Type Motor

PurposeThis study aims to propose criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration.Design/methodology/approachThe optimal design of the stator and rotor can be enhanced using both a response surface method (RSM) and finite element method (FEM). In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor.FindingsThe criteria not only improve performance but also reduce manufacturing costs. The criteria are verified FEM together with an RSM. These methods are used to optimize the stator and rotor shape and the magnetization system. These methods allow us to produce an efficient system for mass production of the motor.Originality/valueThis study proposed a design method that uses rare earth magnets in a system to replace the spoke-type IPM. To verify the optimal design, torque characteristics were analysed using FEM and RSM. Excellent results were achieved regarding the reduction of cogging torque and torque ripple. In addition, the design of the magnetizer enables a cost-effective mass production system for the motor.

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