Crashworthiness optimization of new thin-walled cellular configurations

2014 ◽  
Vol 31 (5) ◽  
pp. 879-897 ◽  
Author(s):  
Shujuan Hou ◽  
Zhidan Zhang ◽  
Xujing Yang ◽  
Hanfeng Yin ◽  
Qing Li

Purpose – The purpose of this paper is to optimize a new thin-walled cellular configurations with crashworthiness criteria, so as to improve the crashworthiness of components of a vehicle body. Design/methodology/approach – ANSYS Parametric Design Language is used to create the parameterized models so that the design variables can be changed conveniently. Moreover, the surrogate technique, namely response surface method, is adopted for fitting objective and constraint functions. The factorial design and D-optimal criterion are employed to screen active parameters for constructing the response functions of the specific energy absorption and the peak crushing force. Finally, sequential quadratic programming-NLPQL is utilized to solve the design optimization problem of the new cellular configurations filled with multi-cell circular tubes under the axial crushing loading. Findings – Two kinds of distribution modes of the cellular configurations are first investigated, which are in an orthogonal way and in a diamond fashion. After comparing the optimized configurations of the rectangular distribution with the annular distribution of the multi-cell fillers, it is found that the orthogonal way seems better in the aspects of crashworthiness than the diamond fashion. Originality/value – The two new thin-walled cellular configuration are studied and optimized with the crashworthiness criteria. Study on the new cellular configurations is very valuable for improving the crashworthiness of components of a vehicle body. Meanwhile, the factorial design and the factor screening are adopted in the process of the crashworthiness optimization of the new thin-walled cellular configurations.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdi Valitabar ◽  
Mohammadjavad Mahdavinejad ◽  
Henry Skates ◽  
Peiman Pilechiha

PurposeThe aim of this paper is to present a parametric design method to generate optimum adaptive facades regarding occupants' comfort and building energy criteria. According to the literature review, the following questions have arisen to address the research gaps: Is it possible to have the outside view throughout the whole year without discomfort glare by utilising adaptive solar facades (ASFs)? How can architects integrate both view quality and quantity into ASF design? What is the impact of dynamic vertical shading systems mounted on south facades on the outside view, occupants' visual comfort and operational energy? How can we evaluate the view quantity through multi-layer shading systems?Design/methodology/approachIn recent years, there is a surge in demand for fully glazed buildings, motivating both architects and scholars to explore novel ideas for designing adaptive solar facades. Nevertheless, the view performance of such systems has not been fully explored especially when it comes to the effect of dynamic vertical shading systems mounted on south facades. This fact clarifies the need to conduct more research in this field by taking into account the window view and natural light. Consequently, a simulation research is carried out to investigate the impact of a dynamic shading system with three vertical slats used on the south facade of a single office room located in Tehran, on both view quality and quantity, visual comfort and operational energy. The research attempts to reach a balance between the occupant's requirements and building energy criteria through a multi-objective optimisation. The distinctive feature of the proposed method is generating some optimum shading which could only cover the essential parts of the window area. It was detected from the simulation results that the usage of a dynamic vertical shading system with multi slats for south facades compared to common Venetian blinds can firstly, provide four times more view quantity. Secondly, the view quality is significantly improved through enabling occupants to enjoy the sky layer the entire year. Finally, twice more operational energy can be saved while more natural light can enter the indoor environment without glare. The final outcome of this research contributes toward designing high-performance adaptive solar facades.FindingsThis paper proposes a new metric to evaluate the view quantity through a multi-layer shading system. The proposed method makes it clear that the usage of dynamic vertical shading systems with multi-layers mounted on south facades can bring many benefits to both occupants and building energy criteria. The proposed method could (1) provide four times more view quantity; (2) improve view quality by enabling occupants to watch the sky layer throughout the whole year; (3) slash the operational energy by twice; (4) keep the daylight glare probability (DGP) value in the imperceptible range.Research limitations/implicationsThe research limitations that should be acknowledged are ignoring the impact of the adjacent building on sunlight reflection, which could cause discomfort glare issues. Another point regarding the limitations of the proposed optimisation method is the impact of vertical shading systems on users' visual interests. A field study ought to be conducted to determine which one could provide the more desirable outside view: a vertical or horizontal the view. Research on the view performance of ASFs, especially their impact on the quality of view, is sorely lacking.Originality/valueThis paper (1) analyses the performance of dynamic vertical shadings on south facades; (2) evaluates outside view through multi-layer shading systems; and (3) integrates both view quality and quantity into designing adaptive solar facades.


2015 ◽  
Vol 119 (1222) ◽  
pp. 1513-1539 ◽  
Author(s):  
J. W. Lim

AbstractThis design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral, and radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending, and torsion), and the high g manoeuvring pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1·0% in hover, 10·0% at μ = 0·30, and 17·0% at μ = 0·40 relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0·30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.


Author(s):  
Ethan M. Moon ◽  
Vadim V. Yakovlev

PurposeThis paper aims to introduce and illustrate a computational technique capable of determining the geometry and complex permittivity of a supplementary dielectric insert making distributions of microwave-induced dissipated power within the processed material as uniform as possible.Design/methodology/approachThe proposed technique is based on a 3D electromagnetic model of the cavity containing both the processed material and the insert. Optimization problem is formulated for design variables (geometrical and material parameters of the insert) identified from computational tests and an objective function (the relative standard deviation [RSD]) introduced as a metric of the field uniformity. Numerical inversion is performed with the method of sequential quadratic programming.FindingsFunctionality of the procedure is illustrated by synthesis of a dielectric insert in an applicator for microwave fixation. Optimization is completed for four design variables (two geometrical parameters, dielectric constant and the loss factor of the insert) with 1,000 points in the database. The best three optimal solutions provide RSD approximately 20 per cent, whereas for the patterns corresponding to all 1,000 non-optimized (randomly chosen) sets of design variables this metric is in the interval from 27 to 136 per cent with the average of 78 per cent.Research limitations/implicationsAs microwave thermal processing is intrinsically inhomogeneous and the heating time is not a part of the underlying model, the procedure is able to lead only to a certain degree of closeness to uniformity and is intended for applications with high heating rates. The initial phase of computational identification of design variables and their bounds is therefore very important and may pre-condition the “quality” of the optimal solution. The technique may work more efficiently in combination with advanced optimization techniques dealing with “smart” (rather than random) generation of the data; for the use with more general microwave heating processes characterized by lower heating rates, the technique has to use the metric of non-uniformity involving temperature and heating time.Practical implicationsWhile the procedure can be used for computer-aided design (CAD) of microwave applicators, a related practical limitation may emerge from the fact that the material with particular complex permittivity (determined in the course of optimization) may not exist. In such cases, the procedure can be rerun for the constant values of material parameters of the available medium mostly close to the optimal ones to tune geometrical parameters of the insert. Special manufacturing techniques capable of producing a material with required complex permittivity also may be a practical option here.Originality/valueNon-uniformity of microwave heating remains a key challenge in the design of many practical applicators. This paper suggests a concept of a practical CAD and outlines corresponding computational procedure that could be used for designing a range of applied systems with high heating rates.


2020 ◽  
Vol 40 (5) ◽  
pp. 703-721
Author(s):  
Golak Bihari Mahanta ◽  
Deepak BBVL ◽  
Bibhuti B. Biswal ◽  
Amruta Rout

Purpose From the past few decades, parallel grippers are used successfully in the automation industries for performing various pick and place jobs due to their simple design, reliable nature and its economic feasibility. So, the purpose of this paperis to design a suitable gripper with appropriate design parameters for better performance in the robotic production systems. Design/methodology/approach In this paper, an enhanced multi-objective ant lion algorithm is introduced to find the optimal geometric and design variables of a parallel gripper. The considered robotic gripper systems are evaluated by considering three objective functions while satisfying eight constraint equations. The beta distribution function is introduced for generating the initial random number at the initialization phase of the proposed algorithm as a replacement of uniform distribution function. A local search algorithm, namely, achievement scalarizing function with multi-criteria decision-making technique and beta distribution are used to enhance the existing optimizer to evaluate the optimal gripper design problem. In this study, the newly proposed enhanced optimizer to obtain the optimum design condition of the design variables is called enhanced multi-objective ant lion optimizer. Findings This study aims to obtain optimal design parameters of the parallel gripper with the help of the developed algorithms. The acquired results are investigated with the past research paper conducted in that field for comparison. It is observed that the suggested method to get the best gripper arrangement and variables of the parallel gripper mechanism outperform its counterparts. The effects of the design variables are needed to be studied for a better design approach concerning the objective functions, which is achieved by sensitivity analysis. Practical implications The developed gripper is feasible to use in the assembly operation, as well as in other pick and place operations in different industries. Originality/value In this study, the problem to find the optimum design parameter (i.e. geometric parameters such as length of the link and parallel gripper joint angles) is addressed as a multi-objective optimization. The obtained results from the execution of the algorithm are evaluated using the performance indicator algorithm and a sensitivity analysis is introduced to validate the effects of the design variables. The obtained optimal parameters are used to develop a gripper prototype, which will be used for the assembly process.


2020 ◽  
Vol 25 (1) ◽  
pp. 9-16
Author(s):  
Erkut Yalçın ◽  
Halil Bilal ◽  
Ayhan Yağcı ◽  
Haluk Erol

A Vibro-Acoustic Finite Element Method (FEM) model capable of calculating the transient sound pressure generated by the door slam of a vehicle was developed in this study. A design sensitivity analysis (DSA) was performed for investigating the effects of major design variables on the related sound quality metrics. The methodology was developed using a sedan-car and its FEM model. This paper shows that a Computer Aided Engineering (CAE) model can be used as a rather powerful tool for giving design change decisions for the door components from sound quality point of view during vehicle body development according to psychoacoustic parameters.


2014 ◽  
Vol 28 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Steven W. Rayburn

Purpose – The purpose of this article is to employ Self-Determination Theory to explain the mediated impact of work design – empowerment and serial and investiture socialization – on employee work affect. The theory proposes fulfilment of three psychological needs – autonomy, competence, and relatedness – will mediate individuals' ability to achieve contextually relevant well-being. An empirical study tests this claim and exposes the structure of the mediating effects. Design/methodology/approach – Survey responses were collected from a sample of 239 front-line service employees using snowball data collection. SEM was used to test hypotheses. Findings – Findings suggest that empowerment and serial and investiture socialization are significantly differentially related to need fulfilment. Additionally, all forms of need fulfilment do not directly influence employee affect. Instead, there are both direct and interactive effects that work simultaneously to influence employees' positive work affect. Practical implications – This study exposes specific work design levers managers can manipulate to benefit employees. This research highlights the different effects of specific work design variables on employee work affect. Originality/value – This paper extends understanding of Self-Determination Theory by exposing the direct and interactive effects of need fulfilment on work affect for service workers. Also, it delivers a deeper exploration of the impact of work design on employees by modelling multiple work design variables as well as process variables simultaneously to provide a more detailed picture of how work design influences employee work affect.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jiandong Zhou ◽  
Xiang Li ◽  
Xiande Zhao ◽  
Liang Wang

PurposeThe purpose of this paper is to deal with the practical challenge faced by modern logistics enterprises to accurately evaluate driving performance with high computational efficiency under the disturbance of road smoothness and to identify significantly associated performance influence factors.Design/methodology/approachThe authors cooperate with a logistics server (G7) and establish a driving grading system by constructing real-time inertial navigation data-enabled indicators for both driving behaviour (times of aggressive speed change and times of lane change) and road smoothness (average speed and average vibration times of the vehicle body).FindingsThe developed driving grading system demonstrates highly accurate evaluations in practical use. Data analytics on the constructed indicators prove the significances of both driving behaviour heterogeneity and the road smoothness effect on objective driving grading. The methodologies are validated with real-life tests on different types of vehicles, and are confirmed to be quite effective in practical tests with 95% accuracy according to prior benchmarks. Data analytics based on the grading system validate the hypotheses of the driving fatigue effect, daily traffic periods impact and transition effect. In addition, the authors empirically distinguish the impact strength of external factors (driving time, rainfall and humidity, wind speed, and air quality) on driving performance.Practical implicationsThis study has good potential for providing objective driving grading as required by the modern logistics industry to improve transparent management efficiency with real-time vehicle data.Originality/valueThis study contributes to the existing research by comprehensively measuring both road smoothness and driving performance in the driving grading system in the modern logistics industry.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
José M. Zea Pérez ◽  
Jorge Corona-Castuera ◽  
Carlos Poblano-Salas ◽  
John Henao ◽  
Arturo Hernández Hernández

Purpose The purpose of this paper is to study the effects of printing strategies and processing parameters on wall thickness, microhardness and compression strength of Inconel 718 superalloy thin-walled honeycomb lattice structures manufactured by laser powder bed fusion (L-PBF). Design/methodology/approach Two printing contour strategies were applied for producing thin-walled honeycomb lattice structures in which the laser power, contour path, scanning speed and beam offset were systematically modified. The specimens were analyzed by optical microscopy for dimensional accuracy. Vickers hardness and quasi-static uniaxial compression tests were performed on the specimens with the least difference between the design wall thickness and the as built one to evaluate their mechanical properties and compare them with the counterparts obtained by using standard print strategies. Findings The contour printing strategies and process parameters have a significant influence on reducing the fabrication time of thin-walled honeycomb lattice structures (up to 50%) and can lead to improve the manufacturability and dimensional accuracy. Also, an increase in the young modulus up to 0.8 times and improvement in the energy absorption up to 48% with respect to those produced by following a standard strategy was observed. Originality/value This study showed that printing contour strategies can be used for faster fabrication of thin-walled lattice honeycomb structures with similar mechanical properties than those obtained by using a default printing strategy.


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