Search results

1 – 10 of over 19000
Article
Publication date: 18 August 2022

Zhufeng Yue, Ming Li, Lei Li and Zude Zhou

This paper aims to propose a new concept of product manufacturing mode which takes physical manufacturing theory as the basic starting point. In this work, the authors intend to…

132

Abstract

Purpose

This paper aims to propose a new concept of product manufacturing mode which takes physical manufacturing theory as the basic starting point. In this work, the authors intend to systematically define the basic connotation and extension of physical manufacturing, and sort out the typical characteristics of physical manufacturing, in order to propose the general concept of physical manufacturing.

Design/methodology/approach

How to study the combination of physics, mathematics, mechanics and other disciplines with the manufacturing disciplines, and how to elevate modern manufacturing science to a new height, has always been a problem for scientists in the field of manufacturing and engineering construction people to deeply think about. Therefore, on the basis of tracing the development of physics and combining the attributes and functions of manufacturing, the authors propose the basic concept of physical manufacturing. On this basis, the authors further clarify the connotation and extension, theoretical basis and technical system of physical manufacturing, reveal the basic problem domain of research and construct the theoretical foundation of physical manufacturing research, which are of great theoretical value and practical significance to adjust and optimize the manufacturing industry structure, improve the quality of manufacturing industry development and promote the green development of manufacturing industry.

Findings

The research on the basic theory and technical system of physical manufacturing will therefore broaden the way of thinking and make a better understanding of manufacturing science and technology, which will promote the development of manufacturing industry to some extent.

Originality/value

On the basis of continuous improvement of the basic theory and conceptual system of physical manufacturing, the physical manufacturing technology will become more and more perfect; physical manufacturing system and intelligent manufacturing system will become the mainstream of next-generation manufacturing system.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 11 November 2013

Bo Zhao

– The purpose of this paper is to attempt to predict the fiber diameter of melt blowing nonwovens by means of physics model.

Abstract

Purpose

The purpose of this paper is to attempt to predict the fiber diameter of melt blowing nonwovens by means of physics model.

Design/methodology/approach

The effects of the processing parameters on the fiber diameter is studied using the established physics model.

Findings

The results show that the predicted and experimental values agree well, the physics model produces more accurate and stable predictions, which also indicates that the physics model is really an effective and available modeling method for predictors.

Originality/value

The results show the great potential of this research for computer assisted design of the melt blowing technology.

Details

International Journal of Clothing Science and Technology, vol. 25 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 March 1984

BRUCE C. BENNION and SUNEE KARSCHAMROON

Multiple regression models can be used to rank physics journals in approximately the same order as the journals are perceived useful by actual users. Four such regression models

Abstract

Multiple regression models can be used to rank physics journals in approximately the same order as the journals are perceived useful by actual users. Four such regression models are reported here, each having a multiple R value of ·74 or greater. Perceived usefulness, the dependent variable used in constructing the models, was obtained from a survey of 167 physicists in the US and Canada. The independent, or predictor variables include easily obtainable bibliometric statistics such as number of source items published, immediacy index, ratio of citations received to citations made, total citations received, impact factor and others. Regression models that combine certain of these statistics can predict user valuation of the journals better than any single bibliometric predictor alone can do. Their advantage for serials management is in ease of estimating usefulness as judged by users, a much more difficult statistic to obtain. Where these models may not apply, it is relatively simple to construct similar models based upon surveys of other user groups. It appears likely that good models of this type can also be developed for many other disciplines.

Details

Journal of Documentation, vol. 40 no. 3
Type: Research Article
ISSN: 0022-0418

Article
Publication date: 28 April 2020

Esther Cascarosa, Carlos Sánchez-Azqueta, Cecilia Gimeno and Concepción Aldea

Until relatively recently, science teaching was based on conveying theoretical concepts. Nevertheless, in the last few years we have gradually understood the importance of…

Abstract

Purpose

Until relatively recently, science teaching was based on conveying theoretical concepts. Nevertheless, in the last few years we have gradually understood the importance of building mental models that represent scientific reality. Model-based science teaching has been used at a school level with satisfactory results. However, only a few studies have been published so far on science modelling in higher education.

Design/methodology/approach

The present thematic review analyses the concept of model in science and the works published in recent years on models in physics education.

Findings

Throughout these years, special importance has been given to the acquisition of student learning models. These models can either be introduced in the teaching process or acquired by students in their learning process using specific teaching tools. As a conclusion of this review, the authors say that although such strategies are increasingly used in the teaching of science at a school level, few works delve into the importance of acquiring models in higher education. More specifically, there are few research works published in the context of teaching physics in university courses.

Originality/value

This study review and analyses works published on this issue and aims to provide knowledge as a starting point for future research.

Details

Journal of Applied Research in Higher Education, vol. 13 no. 1
Type: Research Article
ISSN: 2050-7003

Keywords

Article
Publication date: 8 June 2015

Mica Grujicic, Rohan Galgalikar, S. Ramaswami, Jennifer Snipes, Ramin Yavari and Rajendra K. Bordia

A multi-physics process model is developed to analyze reactive melt infiltration (RMI) fabrication of ceramic-matrix composite (CMC) materials and components. The paper aims to…

Abstract

Purpose

A multi-physics process model is developed to analyze reactive melt infiltration (RMI) fabrication of ceramic-matrix composite (CMC) materials and components. The paper aims to discuss this issue.

Design/methodology/approach

Within this model, the following key physical phenomena governing this process are accounted for: capillary and gravity-driven unsaturated flow of the molten silicon into the SiC/SiC CMC preform; chemical reactions between the silicon melt and carbon (either the one produced by the polymer-binder pyrolysis or the one residing within the dried matrix slurry); thermal-energy transfer and source/sink phenomena accompanying reactive-flow infiltration; volumetric changes accompanying chemical reactions of the molten silicon with the SiC preform and cooling of the as-fabricated CMC component to room temperature; development of residual stresses within, and thermal distortions of, the as-fabricated CMC component; and grain-microstructure development within the SiC matrix during RMI.

Findings

The model is validated, at the material level, by comparing its predictions with the experimental and modeling results available in the open literature. The model is subsequently applied to simulate RMI fabrication of a prototypical gas-turbine engine hot-section component, i.e. a shroud. The latter portion of the work revealed the utility of the present computational approach to model fabrication of complex-geometry CMC components via the RMI process.

Originality/value

To the authors’ knowledge, the present work constitutes the first reported attempt to apply a multi-physics RMI process model to a gas-turbine CMC component.

Details

Multidiscipline Modeling in Materials and Structures, vol. 11 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 9 December 2022

Kaitlyn Gee, Suh In Kim, Haden Quinlan and A. John Hart

This study presents a framework to estimate throughput and cost of additive manufacturing (AM) as related to process parameters, material thermodynamic properties and machine…

Abstract

Purpose

This study presents a framework to estimate throughput and cost of additive manufacturing (AM) as related to process parameters, material thermodynamic properties and machine specifications. Taking a 3D model of the part design as input, the model uses a parametrization of the rate-limiting physics of the AM build process – herein focusing on laser powder bed fusion (LPBF) and scaling of LPBF melt pool geometry – to estimate part- and material-specific build time. From this estimate, per-part cost is calculated using a quantity-dependent activity-based production model.

Design/methodology/approach

Analysis tools that assess how design variables and process parameters influence production cost increase our understanding of the economics of AM, thereby supporting its practical adoption. To this aim, our framework produces a representative scaling among process parameters, build rate and production cost.

Findings

For exemplary alloys and LPBF system specifications, predictions reveal the underlying tradeoff between production cost and machine capability, and look beyond the capability of currently commercially available equipment. As a proxy for build quality, the number of times each point in the build is re-melted is derived analytically as a function of process parameters, showcasing the tradeoff between print quality due to increased melting cycles, and throughput.

Originality/value

Typical cost models for AM only assess single operating points and are not coupled to models of the representative rate-limiting process physics. The present analysis of LPBF elucidates this important coupling, revealing tradeoffs between equipment capability and production cost, and looking beyond the limits of current commercially available equipment.

Details

Rapid Prototyping Journal, vol. 29 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 16 April 2018

Garrison N. Stevens, Sez Atamturktur, D. Andrew Brown, Brian J. Williams and Cetin Unal

Partitioned analysis is an increasingly popular approach for modeling complex systems with behaviors governed by multiple, interdependent physical phenomena. Yielding accurate…

Abstract

Purpose

Partitioned analysis is an increasingly popular approach for modeling complex systems with behaviors governed by multiple, interdependent physical phenomena. Yielding accurate representations of reality from partitioned models depends on the availability of all necessary constituent models representing relevant physical phenomena. However, there are many engineering problems where one or more of the constituents may be unavailable because of lack of knowledge regarding the underlying principles governing the behavior or the inability to experimentally observe the constituent behavior in an isolated manner through separate-effect experiments. This study aims to enable partitioned analysis in such situations with an incomplete representation of the full system by inferring the behavior of the missing constituent.

Design/methodology/approach

This paper presents a statistical method for inverse analysis infer missing constituent physics. The feasibility of the method is demonstrated using a physics-based visco-plastic self-consistent (VPSC) model that represents the mechanics of slip and twinning behavior in 5182 aluminum alloy. However, a constituent model to carry out thermal analysis representing the dependence of hardening parameters on temperature is unavailable. Using integral-effect experimental data, the proposed approach is used to infer an empirical constituent model, which is then coupled with VPSC to obtain an experimentally augmented partitioned model representing the thermo-mechanical properties of 5182 aluminum alloy.

Findings

Results demonstrate the capability of the method to enable model predictions dependent upon relevant operational conditions. The VPSC model is coupled with the empirical constituent, and the newly enabled thermal-dependent predictions are compared with experimental data.

Originality/value

The method developed in this paper enables the empirical inference of a functional representation of input parameter values in lieu of a missing constituent model. Through this approach, development of partitioned models in the presence of uncertainty regarding a constituent model is made possible.

Details

Engineering Computations, vol. 35 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 15 January 2018

Andrei Khrennikov

This paper aims to present the basic assumptions for creation of social lasers and attract attention of other researchers (both from physics and socio-political science) to the…

Abstract

Purpose

This paper aims to present the basic assumptions for creation of social lasers and attract attention of other researchers (both from physics and socio-political science) to the problem of modeling of Stimulated Amplification of Social Actions (SASA).

Design/methodology/approach

The model of SASA and its analysis are based on the mathematical formalism of quantum thermodynamics and field theory (applied outside of physics).

Findings

The presented quantum-like model provides the consistent operational model of such complex socio-political phenomenon as SASA.

Research limitations/implications

The model of SASA is heavily based on the use of the notion of social energy. This notion has not yet been formalized.

Practical implications

Evidence of SASA (“functioning of social lasers”) is rapidly accumulating, from color revolutions to such democratically structured protest actions as Brexit and the recent election of Donald Trump as the President of the USA. The corresponding socio-political studies are characterized by diversity of opinions and conclusions. The presented social laser model can be used to clarify these complex socio-political events and even predict their possibility.

Social implications

SASA is the powerful source of social instability. Understanding its informational structure and origin may help to stabilize the modern society.

Originality/value

Application of the quantum-like model of laser technology in social and political sciences is really a novel and promising approach.

Article
Publication date: 3 July 2017

Anand Amrit, Leifur Leifsson and Slawomir Koziel

This paper aims to investigates several design strategies to solve multi-objective aerodynamic optimization problems using high-fidelity simulations. The purpose is to find…

Abstract

Purpose

This paper aims to investigates several design strategies to solve multi-objective aerodynamic optimization problems using high-fidelity simulations. The purpose is to find strategies which reduce the overall optimization time while still maintaining accuracy at the high-fidelity level.

Design/methodology/approach

Design strategies are proposed that use an algorithmic framework composed of search space reduction, fast surrogate models constructed using a combination of physics-based surrogates and kriging and global refinement of the Pareto front with co-kriging. The strategies either search the full or reduced design space with a low-fidelity model or a physics-based surrogate.

Findings

Numerical investigations of airfoil shapes in two-dimensional transonic flow are used to characterize and compare the strategies. The results show that searching a reduced design space produces the same Pareto front as when searching the full space. Moreover, as the reduced space is two orders of magnitude smaller (volume-wise), the number of required samples to setup the surrogates can be reduced by an order of magnitude. Consequently, the computational time is reduced from over three days to less than half a day.

Originality/value

The proposed design strategies are novel and holistic. The strategies render multi-objective design of aerodynamic surfaces using high-fidelity simulation data in moderately sized search spaces computationally tractable.

Article
Publication date: 18 January 2013

Tugrul Oktay and Cornel Sultan

The purpose of this paper is to show the feasibility of constrained model predictive control (MPC) for sophisticated helicopter models which are derived by physical considerations.

Abstract

Purpose

The purpose of this paper is to show the feasibility of constrained model predictive control (MPC) for sophisticated helicopter models which are derived by physical considerations.

Design/methodology/approach

Physics‐based modeling is used to create control‐oriented helicopter models. Advanced constrained controllers are designed and tested for these sophisticated models.

Findings

The helicopter models are valid and constrained MPC shows considerable promise for robust tracking.

Practical implications

MPCs can be implemented for highly constrained helicopter flights.

Originality/value

A complete process of control‐oriented, physics‐based model development for helicopters followed by MPC design is developed. It is also proved that constrained MPC can be used and implemented online to robustly track discontinuous helicopter trajectories with heterogeneous constraints, even when the models are sophisticated and physics based.

Details

Aircraft Engineering and Aerospace Technology, vol. 85 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

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