scholarly journals Efficient Design of Thin Wall Seating Made of a Single Piece of Heavy-Duty Corrugated Cardboard

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6645
Author(s):  
Berta Suarez ◽  
Luisa M. Muneta ◽  
Gregorio Romero ◽  
Juan D. Sanz-Bobi
Keyword(s):  
Design Process ◽  
Numerical Models ◽  
Thin Wall ◽  
Efficient Design ◽  
Heavy Duty ◽  
Single Piece ◽  
Corrugated Cardboard ◽  
Homogenization Methods ◽  
First Time ◽  
Double Wall

Corrugated cardboard has waved cores with small flutes that prevent the use of detailed numerical models of whole structures. Many homogenization methods in the literature overcome this drawback by defining equivalent homogeneous plates with the same mechanical behaviour at a macro-mechanical scale. However, few homogenization works have considered complete structures, focusing mainly on beams or plates. For the first time, this study explores the application of homogenization approaches to larger structures as an aid in their design process. We also considered triple-wall boards rather than single- and double-wall configurations commonly addressed in the literature. To this end, we adapted the homogenization methods proposed by Talbi and Duong to analyze thin-walled stools made of triple-wall corrugated cardboard. Using a progressive design process, we performed an efficient stool design by removing material zones with lower stresses, with 35% less material, 35% lower vertical deflections, and 66% lower stresses than the initial design. Unlike other corrugated cardboard stools, this design comprises just one folded piece instead of three, thus saving storage space. These results demonstrate the utility of homogenization techniques as an aid in the design process of whole structures made of corrugated cardboard. Further research will consider buckling analysis.

Improving the Volumetric Efficiency of the Axial Piston Pump

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Shu Wang
Keyword(s):  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Efficient Design ◽  
Axial Piston Pumps ◽  
Definition Of ◽  
Engineering Practices ◽  
First Time ◽  
Axial Piston

The volumetric efficiency is one of the most important aspects of system performance in the design of axial piston pumps. From the standpoint of engineering practices, the geometric complexities of the valve plate (VP) and its multiple interactions with pump dynamics pose difficult obstacles for optimization of the design. This research uses the significant concept of pressure carryover to develop the mathematical relationship between the geometry of the valve plate and the volumetric efficiency of the piston pump. For the first time, the resulting expression presents the theoretical considerations of the fluid operating conditions, the efficiency of axial piston pumps, and the valve plate designs. New terminology, such as discrepancy of pressure carryover (DPC) and carryover cross-porting (CoCp), is introduced to explain the fundamental principles. The important results derived from this study can provide clear recommendations for the definition of the geometries required to achieve an efficient design, especially for the valve plate timings. The theoretical results are validated by simulations and experiments conducted by testing multiple valve plates under various operating conditions.

Laser Metal Deposition of Fe- and Co-Based Shape-Memory Alloys

2021 ◽  
Vol 1161 ◽  
pp. 105-112
Author(s):  
Niklas Sommer ◽  
Gabriel Mienert ◽  
Malte Vollmer ◽  
Christian Lauhoff ◽  
Philipp Krooß ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Microstructural Evolution ◽  
Microstructural Analysis ◽  
Metal Deposition ◽  
Thin Wall ◽  
Laser Metal Deposition ◽  
Wall Structures ◽  
Iron Based ◽  
First Time

In the present study, Iron-based FeMnAlNi and Cobalt-based CoNiGa shape-memory alloys (SMA) were processed by laser metal deposition for the first time. The materials show susceptibility to cracking upon processing when unheated substrates are employed. Pre-heating of the substrate materials eliminated cracking completely and enabled robust deposition of thin-wall structures. Microstructural analysis using optical microscopy revealed different microstructural evolution for the two materials considered.

scholarly journals Engineering Design Driven by Models and Measures: The Case of a Rigid Inflatable Boat

2018 ◽  
Author(s):  
Cristiano Fragassa
Keyword(s):  
Numerical Methods ◽  
Engineering Design ◽  
Design Process ◽  
Experimental Approach ◽  
Numerical Models ◽  
Stress And Strain ◽  
Engineering Design Process ◽  
Hull Slamming ◽  
Available Information ◽  
Special Case

Rigid-hulled inflatable boats are extremely practical and popular nowadays. They offer a effective conciliation among usability and costs. Their stable and seaworthy behaviour is guaranteed by performing hydroplaning hulls coupled with unsinkable inflated tubes. At the same time, their design is often based on tradition and preconceptions. Rarely, the design assumptions are validated by the reality or, even, by deeper investigations. In this article, both numerical methods and experimental mechanics techniques are proposed as an essential way for supporting the designers in their decisive tasks. Three different situations are detailed where a numerical or an experimental approach shows its benefit inside the engineering design process: firstly permitting to investigate the behaviour of materials driving the fiberglass selection; then measuring the levels of stress and strain in the hull during sailing; finally, using all available information as a base for developing numerical models of the hull slamming in waves. Even if the discussion is focused on a rigid inflatable boat, large part of its considerations is relevant beyond this special case.

scholarly journals An Evaluation-Driven Design Process for Exhibitions

2017 ◽  
Author(s):  
Wolfgang Leister ◽  
Ingvar Tjøstheim ◽  
Göran Joryd ◽  
Michel de Brisis ◽  
Syver Lauritzsen ◽  
...  
Keyword(s):  
Design Process ◽  
Informal Education ◽  
Graphical Representation ◽  
Working Relationship ◽  
Efficient Design ◽  
Learning Game ◽  
Science Centre ◽  
Science Centres

Museums and Science Centres are informal education environments that intend to engage the visitors with their exhibits. We present an efficient design process that allows an improved working relationship between museum practitioners, exhibition designers, and visitors. We present the principles and a graphical representation based on the Engagement Profile from previous work. Elements of the design process are evaluated using a learning game at the science centre Engineerium. The evaluation is based on a study with over five hundred visitors to the science centre.

Advanced aircraft performance analysis

2018 ◽  
Vol 90 (4) ◽  
pp. 627-638 ◽  
Author(s):  
Marc Immer ◽  
Philipp Georg Juretzko
Keyword(s):  
Performance Analysis ◽  
Design Process ◽  
Performance Optimization ◽  
Electric Propulsion ◽  
Vertical Plane ◽  
Aircraft Design ◽  
Efficient Design ◽  
Content Type ◽  
Aircraft Performance ◽  
Hybrid Electric

Purpose The preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance optimization is often challenging, especially for complex mission profiles (e.g. for unmanned aerial vehicles [UAVs]) or hybrid-electric propulsion. Therefore, the purpose of this study is to find a methodology that supports aircraft performance analysis and that is applicable to complex profiles and to novel designs. Design/methodology/approach As its core element, the developed method uses a computationally efficient C++ software “Aircraft Performance Program” (APP), which performs a segment-based mission computation. APP performs a time integration of the equations of motion of a point mass in the vertical plane. APP is called via a command line interface from a flexible scripting language (Python). On top of APP’s internal radius of action optimization, state-of-the-art optimization packages (SciPy) are used. Findings The application of the method to a conventional climb schedule shows that the definition of the top of climb has a significant influence on the resulting optimum. Application of the method to a complex UAV mission optimization, which included maximizing the radius of action, was successful. Low computation time enables to perform large parametric studies. This greatly improves the interpretation of the results. Research limitations/implications The scope of the paper is limited to the methodology that allows for advanced performance analysis at the conceptual and preliminary design stages with an emphasis on novel propulsion concepts. The methodology is developed using existing, validated methods, and therefore, this paper does not contain comprehensive validation. Other disciplines, such as cost analysis, life-cycle assessment or market analysis, are not considered. Practical implications With the proposed method, it is possible to obtain not only the desired optimum mission performance but also off-design performance of the investigated design. A thorough analysis of the mission performance provides insight into the design’s capabilities and shortcomings, ultimately aiding in obtaining a more efficient design. Originality/value Recent developments in the area of hybrid or hybrid-electric propulsion systems have shown the need for performance computation tools aiding the related design process. The presented method is especially valuable when novel design concepts with complex mission profiles are investigated.

Reacting to Re: Activism

2010 ◽  
pp. 274-290
Author(s):  
Colleen Macklin
Keyword(s):  
Design Process ◽  
Thick Description ◽  
Ethical Choices ◽  
First Time

This case study of the big urban game Re:Activism examines moments where failures in the game’s design revealed how the design process itself is a set of ethical choices and actions, illustrating specific strategies for integrating more interesting choices into games. Ethics in a game is not inherent; it is enacted through rules, mechanics and play. This chapter is a “thick description” of the first time Re:Activism was played in which the losing team paradoxically had the kind of engaging experience the designers sought to create.

Automated design process for hybrid regression modeling with a one-class SVM

2019 ◽  
Vol 67 (10) ◽  
pp. 843-852 ◽  
Author(s):  
Moritz Böhland ◽  
Wolfgang Doneit ◽  
Lutz Gröll ◽  
Ralf Mikut ◽  
Markus Reischl
Keyword(s):  
Design Process ◽  
Regression Models ◽  
Data Science ◽  
Automated Design ◽  
Model Complexity ◽  
Support Vector ◽  
Local Data ◽  
Benchmark Datasets ◽  
Data Coverage ◽  
First Time

Abstract The accuracy of many regression models suffers from inhomogeneous data coverage. Models loose accuracy because they are unable to locally adapt the model complexity. This article develops and evaluates an automated design process for the generation of hybrid regression models from arbitrary submodels. For the first time, these submodels are weighted by a One-Class Support Vector Machine, taking local data coverage into account. Compared to reference regression models, the newly developed hybrid models achieve significant better results in nine out of ten benchmark datasets. To enable straightforward usage in data science, an implementation is integrated in the open source MATLAB toolbox SciXMiner.

scholarly journals Analysis and Design of a High-Performance Traction Motor for Heavy-Duty Vehicles

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3150
Author(s):  
Dong-Kyu Lee ◽  
Jong-Suk Ro
Keyword(s):  
Design Process ◽  
High Performance ◽  
Permanent Magnet Synchronous Motor ◽  
Harmonic Distortion ◽  
Heavy Vehicles ◽  
Heavy Duty ◽  
Traction Motor ◽  
Analysis And Design ◽  
Power Characteristics ◽  
Heavy Duty Vehicles

Due to environmental issues and depletion of resources, global attentiveness in electric vehicles (EVs) is growing. In particular, research on high specification motors for driving large EVs has attracted a lot of attention. In this study, an analysis and design process for a motor that can be universally applied in heavy vehicles to reduce environmental pollution was introduced. Motors for driving heavy vehicles require high specifications. Thus, an interior permanent magnet synchronous motor (IPMSM) with a delta-shaped magnet array was used to improve the torque and power characteristics. A step skew rotor structure was also used to dampen vibration and noise by minimizing the high-order harmonics in the cogging torque. The proposed analysis and design approach also reduces the total harmonic distortion (THD) of the back electromotive force (EMF). The effectiveness of the proposed analysis and design process and the usefulness of the resulting high-performance traction motor for heavy-duty vehicles were verified via the finite element method (FEM) and by experiment.

Study on Static Assembly Interference Pressure between a Thin-Wall Flexible Cup and a Hollow Flexible Shaft

2011 ◽  
Vol 179-180 ◽  
pp. 212-219
Author(s):  
Guo Ping Wang ◽  
Hua Ling Chen ◽  
She Miao Qi ◽  
Jiu Hui Wu ◽  
Lie Yu
Keyword(s):  
Cylindrical Shell ◽  
Pressure Distribution ◽  
Superposition Principle ◽  
Special Solution ◽  
Thin Wall ◽  
Thin Cylindrical Shell ◽  
Bending Deformation ◽  
Flexible Shaft ◽  
First Time ◽  
Thin Shell Theory

Distribution of static interference pressure between a thin-wall flexible cup and a flexible shaft fluctuates heavily along the axis of the cup and is quite different from pressure distribution of common interference styles. In this article, aiming at solving distribution of static interference pressure between a thin-wall flexible cup with much thicker bottom and a hollow flexible shaft, mechanical model and mathematical model of solving the problem were built based on classic thin shell theory. Special difference is that precise special solution of bending equation of thin cylindrical shell was used to substitute the special solution which is original from bending deformation of thin cylindrical shell in no moment status. And a brand new general solution, the relational expression between bending deformation of thin wall of the cup and distribution of the static interference pressure, was obtained. Then, a method used to solve the pressure distribution was presented by solving integral equation and applying superposition principle for the first time. Through using the method to solve an example and comparing calculated results with FEM results, it was proved that the method is correct and effective.

scholarly journals Development of a THMC code for bentonites in COMSOL Multiphysics

2020 ◽  
Vol 195 ◽  
pp. 04002
Author(s):  
Ángel Yustres ◽  
Rubén López-Vizcaíno ◽  
Virginia Cabrera ◽  
Vicente Navarro
Keyword(s):  
Reactive Transport ◽  
Transport Model ◽  
Numerical Models ◽  
Swelling Pressure ◽  
Double Porosity ◽  
Comsol Multiphysics ◽  
Chemical Potentials ◽  
Definition Of ◽  
High Degree ◽  
First Time

The proposed use of active clays for the isolation of radioactive wastes in deep geological repositories has been followed by a deeper understanding of this type of soils. This increased knowledge has led to the need for both conceptual and numerical models capable of capturing the main trends in behaviour and the different couplings between different physical-chemical phenomena. In addition, the model must have a high degree of flexibility that enables it to accommodate future developments or new relevant phenomena. This work presents a numerical THMC code developed entirely on the COMSOL Multiphysics numerical implementation platform, which provides the required adaptability. This model includes, for the first time in this environment, a reactive transport model in unsaturated porous media for a relevant geochemical system (consistent with the MX-80 bentonite) together with a THM model based on a double porosity approach. The chemical potentials of water and solutes are used for the definition of thermodynamic equilibria between both porosity levels. Trends in the behaviour of a bentonite sample under oedometric conditions are satisfactorily simulated in response to a process of saturation and change in salinity conditions. Variations in swelling pressure, porosity distribution or dissolution/precipitation of the main accessory minerals are analysed and explained by means of the proposed conceptual model.

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