A preliminary mechanical design evaluation of the Wikispeed car: for light-weighting implications

Purpose Road passenger transportation faces a global challenge of reducing environmental pollution and greenhouse gas emissions because of the vehicle weight increases needed to enhance passenger safety and comfort. This paper aims to present a preliminary mechanical design evaluation of the Wikispeed Car (with a focus on body bending, body torsion and body crash) to assess light-weighting implications and improve the vehicle’s environmental performance without compromising safety. Design/methodology/approach For this research, finite element analysis (FEA) was performed to examine the Wikispeed chassis for light-weighting opportunities in three key aspects of the vehicle’s design, namely, for body bending the rockers (or longitudinal tubes), for body torsion (again on the rockers but also the chassis as a whole) and for crash safety – on the frontal crash structure. A two-phase approach was adopted, namely, in phase one, a 3D CAD geometry was generated and in phase, two FEA was generated. The combination of analysis results was used to develop the virtual model using FEA tools, and the model was updated based on the correlation process. Findings The research revealed that changing the specified material Aluminium Alloy 6061-T651 to Magnesium EN-MB10020 allows vehicle mass to be reduced by an estimated 110 kg, thus producing a concomitant 10 per cent improvement in fuel economy. The initial results imply that the current beam design made from magnesium would perform worst during a crash as the force required to buckle the beam is the lowest (between 95.2 kN and 134 kN). Steel has the largest bandwidth of force required for buckling and also requires the largest force for buckling (between 317 kN and 540 kN). Originality/value This is the first study of its kind to compare and contrast between material substitution and its impact upon Wikispeed car safety and performance.

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Mechanical Design, Additive Manufacturing, and Performance of Equal Volume Metamaterials

10.31399/asm.cp.ht2021p0238 ◽

2021 ◽

Author(s):

Richárd Horváth ◽

Vendel Barth ◽

Viktor Gonda ◽

Mihály Réger ◽

Imre Felde

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Energy Absorption ◽

Mechanical Design ◽

Area Under The Curve ◽

Cell Number ◽

Element Analysis ◽

Cross Sectional ◽

Unit Cells ◽

And Performance

Abstract In this paper, we study the energy absorption of metamaterials composed of unit cells whose special geometry makes the cross-sectional area and the volume of the bodies generated from them constant (for the same enclosing box dimensions). After a parametric description of such special geometries, we analyzed by finite element analysis the deformation of the metamaterials we have designed during compression. We 3D printed the designed metamaterials from plastic to subject them to real compression. The results of the finite element analysis were compared with the real compaction results. Then, for each test specimen, we plotted its compaction curve. By fitting a polynomial to the compaction curves and integrating it (area under the curve), the energy absorption of the samples can be obtained. As a result of these investigations, we drew a conclusion about the relationship between energy absorption and cell number.

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Primary study of a new permanent magnet flux switching machine over straight and spanned rotor configurations

World Journal of Engineering ◽

10.1108/wje-08-2016-0060 ◽

2016 ◽

Vol 13 (5) ◽

pp. 441-446 ◽

Cited By ~ 1

Author(s):

Mahyuzie Jenal ◽

Erwan Sulaiman ◽

Hassan Ali Soomro ◽

Syed Muhammad Naufal Syed Othman

Keyword(s):

Finite Element ◽

Performance Analysis ◽

Permanent Magnet ◽

High Speed ◽

Primary Study ◽

Element Analysis ◽

Fundamental Study ◽

Content Type ◽

Dimensional Finite Element ◽

And Performance

Purpose The purpose of this paper is to address a fundamental study and performance analysis of a proposed 6Slots-10Poles permanent magnet flux switching machine (PMFSM) using straight rotor (StR) and 6Slots-8Poles PMFSM with spanned rotor (SpR) structure. Design/methodology/approach Design configuration of the proposed machine was developed using commercial finite element analysis package and JMAG-Designer V.14 software, which provides two-dimensional finite element solver throughout the investigation. An electromagnetic performance analysis is carried out and compared over the two proposed topologies which consist of machines no-load and under-load conditions. Findings This paper demonstrates the finding of the proposed StR structure which consist of more favorable three-phase sinusoidal feature, lower cogging torque and higher output torque. Flux density attributes reveal higher established magnetizing flux concentration in StR compared with SpR. Consequently, the StR structure requires low armature current before it may start to rotate and provides better robust construction with less material consumption and cost. Originality/value This paper describes the novel design of a new PMFSM configuration pertinent for high-speed applications.

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Design and fast verification of pocket elliptical journal bearings

Industrial Lubrication and Tribology ◽

10.1108/ilt-11-2011-0103 ◽

2014 ◽

Vol 66 (3) ◽

pp. 393-401 ◽

Cited By ~ 4

Author(s):

Fabrizio Stefani

Keyword(s):

Design Methodology ◽

Journal Bearings ◽

Fast Method ◽

Analysis Method ◽

Element Analysis ◽

Content Type ◽

Finite Element Analysis Method ◽

Bearing Design ◽

And Performance ◽

Industrial Level

Purpose – The purpose of this paper was to conceive a fast method to verify design and performance of elliptical pocket journal bearings. Design/methodology/approach – The computer-aided verification of pocket journal bearings is performed by means of a suitable finite element analysis method. Findings – The results of sample analyses indicate that the machining tolerances are very influential on elliptical pocket bearing performances, and they must be included among the input data. Originality/value – Although elliptical pocket bearings are widely used in turbomachineries, the influence of their design on performance has not been specifically investigated. A lot of works about tribological models are available, but few of them focus on their application to bearing design at the industrial level.

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Systematic design of a new gearbox for concrete mixers

Journal of Engineering Design and Technology ◽

10.1108/jedt-10-2019-0254 ◽

2020 ◽

Vol 18 (6) ◽

pp. 2017-2042 ◽

Cited By ~ 2

Author(s):

Lorenzo Fiorineschi ◽

Susanna Papini ◽

Luca Pugi ◽

Andrea Rindi ◽

Federico Rotini

Keyword(s):

Power Transmission ◽

Mechanical Design ◽

Direct Consequence ◽

Design Approach ◽

Systematic Design ◽

Original Design ◽

Element Analysis ◽

Content Type ◽

Planetary Gearbox ◽

Embodiment Design

Purpose The purpose of this study is to identify an innovative solution for the power transmission gearbox of concrete mixers, according to the specifications provided by the company. Design/methodology/approach A tailored systematic design approach (inspired to the German systematic framework) has been adopted to comprehensively gather the company specifications and perform in-depth design space explorations. Subsequently, an iterative embodiment design approach has been followed to identify the size of the components for the preferred concept, by using acknowledged mechanical design procedures and finite element analysis tools. Findings An innovative cycloidal gearbox has been developed, by merging the kinematics underpinning the classical cycloidal drives and the Wolfrom planetary gearbox. The resulting concept provides high reduction rates with a very high overload capacity. Research limitations/implications The main limitation of the studies is the absence of in-depth evaluations usually performed in the detail design phase. However, this limitation is a direct consequence of the company specifications, which only asked to find a preferred concept and to perform preliminary evaluations. Accordingly, the subsequent design optimization are intended to be performed by the company’s staff. Originality/value The present paper shows an original design approach, opportunely tailored to the design of innovative gearboxes. It can be conveniently adapted and reused by designers involved in similar tasks. Moreover, the designed cycloidal gearbox paves the way for important innovations in the field of concrete mixers, allowing to design more robust and compact devices.

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Non-Linear Analysis of Steam Generator U-Tube In-Plane Vibration

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2013-98163 ◽

2013 ◽

Author(s):

Alan Kepple ◽

Marwan Charrouf ◽

David Rackiewicz ◽

Phillip Rush

Keyword(s):

Steam Generator ◽

Mechanical Design ◽

Contact Forces ◽

Two Phase ◽

Element Analysis ◽

Steam Generator Tube ◽

Unsteady Forces ◽

Plane Vibration ◽

Non Linear ◽

Support Conditions

Unexpected steam generator tube wear has recently been discovered during in-service inspection of newly installed PWR replacement steam generators. The extent of this unexpected tube wear suggests that a new wear mechanism is emerging that is not described by current tube wear models. A key to understanding the emerging unexpected tube wear may be to better understand the effectiveness of the mechanical design for tube support (flat bars with tight clearances) with respect to preventing flow induced tube vibration, and the characteristics of hydraulic forces exerted on tubes. This paper describes the results of a non-linear, dynamic, finite element analysis of steam generator tube in-plane vibration with typical flat bar mechanical supports. Mechanical support conditions such as initial gaps between tube and supports, contact forces between the tube and the supporting flat bars, and the effect of various forces applied to the tubes by fluid flow are investigated. The analysis describes the effect of these conditions on tube in-plane vibration frequency and damping for various tube forcing functions. Computational fluid dynamics calculations that determine the unsteady forces in two-phase flow test geometries are presented. A model describing the emerging unexpected tube wear is also introduced.

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Application of Finite-Element Analysis in the Design of Automotive Elastomeric Components

Rubber Chemistry and Technology ◽

10.5254/1.3536198 ◽

1988 ◽

Vol 61 (3) ◽

pp. 503-533 ◽

Cited By ~ 40

Author(s):

Kenneth N. Morman ◽

Tsung Y. Pan

Keyword(s):

Component Part ◽

Design Evaluation ◽

Element Analysis ◽

Component Reliability ◽

Closed Form Solutions ◽

The Past ◽

Major Benefit ◽

Time Savings ◽

And Performance ◽

Time Required

Abstract FEA provides more detailed information for design than can be possibly measured on an actual component part or computed using classical closed-form solutions. Based on this observation, FEA is an ideal means for developing concept designs. No parts are needed for FEA, while conceptual design evaluation using “cut and try” procedures of the past requires that component parts be molded for testing. Once a rough concept has been developed, FEA can be used more effectively to evaluate design modifications in less than the time required by “cut-and-try” iterations. The major benefit that is realizable from FEA is in time savings. Computer costs can be justified by factors such as efficiency and better component reliability and performance.

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Modeling and performance analysis of machining fixture for near-net-shaped jet engine blade

Assembly Automation ◽

10.1108/aa-08-2018-113 ◽

2019 ◽

Vol 39 (4) ◽

pp. 624-635

Author(s):

Hui Wang ◽

Jingsong Peng ◽

Bing Zhao ◽

Xin-Dong Zhang ◽

Jie Yu ◽

...

Keyword(s):

Performance Analysis ◽

Geometric Dimension ◽

Machining Error ◽

Element Analysis ◽

Jet Engine ◽

Content Type ◽

Engine Blade ◽

And Performance ◽

Fixture System ◽

Fixture Configuration

PurposeNear-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the geometric features of blade, both sculptured surface and thin-walled shape, make the precise machining of blade challenging and difficult owing to its dynamics behaviors under complex clamping and machining loads. This paper aims to present a fundamental approach on modeling and performance analysis of the blade–fixture system.Design/methodology/approachA computerized framework on the complex blade–fixture dynamic behavior has been developed. Theoretical mechanic analysis on blade fixturing and machining is proposed with an especial emphasis on the boundary conditions of the blade–fixture system. Then the finite element analysis (FEA) method is used to simulate the variation trend of preloads, stiffness and blade distortion. The strong influence of parameters of workpiece–fixture configuration on blade distortion and machining error is investigated.FindingsWith a case of real jet engine blade machining, the experimental results and theoretical predictions suggest good agreement on their variation tendency. The loaded pressure of clamps has a critical influence on the total stiff performance of the blade–fixture system, and the profile error of the blade contributes much to the inconsistency in geometric dimension and surface integrity of blades’ machining. In the end, the results also validate the effectiveness of this methodology to predict and improve the performance of the blade–fixture configuration design.Originality/valueThe adaptive machining of near-net-shaped jet engine blade is a new high-performance manufacturing technology in aerospace production. This study provides a fundamental methodology for the performance analysis of blade-fixture system, to clear the variation law of blade distortion during preloading and machining, which will contribute to minimize the machining error and improve productivity.

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A 4-DOF Upper Limb Exoskeleton for Physical Assistance: Design, Modeling, Control and Performance Evaluation

Applied Sciences ◽

10.3390/app11135865 ◽

2021 ◽

Vol 11 (13) ◽

pp. 5865

Author(s):

Muhammad Ahsan Gull ◽

Mikkel Thoegersen ◽

Stefan Hein Bengtson ◽

Mostafa Mohammadi ◽

Lotte N. S. Andreasen Struijk ◽

...

Keyword(s):

Upper Limb ◽

Tracking Control ◽

Degrees Of Freedom ◽

Control Method ◽

Mechanical Design ◽

Trajectory Tracking Control ◽

Upper Limb Exoskeleton ◽

And Performance ◽

Physically Disabled People ◽

Human Upper Limb

Wheelchair mounted upper limb exoskeletons offer an alternative way to support disabled individuals in their activities of daily living (ADL). Key challenges in exoskeleton technology include innovative mechanical design and implementation of a control method that can assure a safe and comfortable interaction between the human upper limb and exoskeleton. In this article, we present a mechanical design of a four degrees of freedom (DOF) wheelchair mounted upper limb exoskeleton. The design takes advantage of non-backdrivable mechanism that can hold the output position without energy consumption and provide assistance to the completely paralyzed users. Moreover, a PD-based trajectory tracking control is implemented to enhance the performance of human exoskeleton system for two different tasks. Preliminary results are provided to show the effectiveness and reliability of using the proposed design for physically disabled people.

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