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Article
Publication date: 1 July 2004

Zhang Zhengyu, Ding Yucheng and Hong Jun

A new method of hollowing rapid prototype models based on STL models and their cross‐sectional contours is presented to meet the demands of hollowed prototypes in casting and…

800

Abstract

A new method of hollowing rapid prototype models based on STL models and their cross‐sectional contours is presented to meet the demands of hollowed prototypes in casting and rapid prototype manufacturing. Offsetting along the Z‐axis and cross‐sectional contour offsetting are employed to perform the hollowing operation. The process performs two‐dimensional Boolean operations on the polygons made by the offset contours of cross‐sectional contours instead of three‐dimensional offsetting of the STL models. This hollowing operation is especially suitable for hollowing STL models with free‐form surfaces. Detailed algorithms are described to generate the correct offset contours of an STL model. Adopting this method, the hollowing process is dramatically simplified and becomes more efficient. This method has been verified by practical case studies, and it is proved that this simplified hollowing operation can reduce the prototype build time and cost.

Details

Rapid Prototyping Journal, vol. 10 no. 3
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 14 June 2011

Weijun Zhu, Dichen Li, Zhengyu Zhang, Ke Ren, Xinglei Zhao, Dangguo Yang, Wei Zhang, Yan Sun and Yiping Tang

The purpose of this paper is to present a novel method to design and fabricate aeroelastic wing models for wind tunnel tests based on stereolithography (SL). This method can…

806

Abstract

Purpose

The purpose of this paper is to present a novel method to design and fabricate aeroelastic wing models for wind tunnel tests based on stereolithography (SL). This method can ensure the structural similarity of both external and internal structures between models and prototypes.

Design/methodology/approach

An aluminum wing‐box was selected as the prototype, and its natural modes were studied by FEA and scaled down to obtain the desired dynamic behavior data. According to similarity laws, the structurally similar model was designed through a sequential design procedure of dimensional scaling, stiffness optimization and mass optimization. An SL model was then fabricated, and its actual natural modes was tested and compared with the desired data of the prototype.

Findings

The first two natural frequencies of the model presented strong correlation with the desired data of the prototype. Both the external and internal structures of the model matched the prototype closely. The SL‐based method can significantly reduce the total mass and simplify the locating operations of balance‐weights. The cost and time for the fabrication were reduced significantly.

Research limitations/implications

Further investigation into the material properties of SL resins including stiffness and damping behaviors due to layered process is recommended toward higher prediction accuracy. Wind tunnel tests are needed to study the in situ performance and durability of SL models.

Originality/value

Although the paper takes a wing‐box as the study object, structurally similar SL models of entire wings can be obtained conveniently, benefiting from the low‐stiffness material properties of SL resins and the fabrication capacity to build complex structures of SL process. This paper enhances the versatility of using SL and other rapid prototyping processes to fabricate models to predict aeroelastic characteristics of aircraft.

Details

Rapid Prototyping Journal, vol. 17 no. 4
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 19 January 2015

Chao Wang, Guofu Yin, Zhengyu Zhang, Shuiliang Wang, Tao Zhao, Yan Sun and Dangguo Yang

– The purpose of this paper is to introduce a novel method for developing static aeroelastic models based on rapid prototyping for wind tunnel testing.

618

Abstract

Purpose

The purpose of this paper is to introduce a novel method for developing static aeroelastic models based on rapid prototyping for wind tunnel testing.

Design/methodology/approach

A metal frame and resin covers are applied to a static aeroelastic wind tunnel model, which uses the difference of metal and resin to achieve desired stiffness distribution by the stiffness similarity principle. The metal frame is made by traditional machining, and resin covers are formed by stereolithgraphy. As demonstrated by wind tunnel testing and stiffness measurement, the novel method of design and fabrication of the static aeroelastic model based on stereolithgraphy is practical and feasible, and, compared with that of the traditional static elastic model, is prospective due to its lower costs and shorter period for its design and production, as well as avoiding additional stiffness caused by outer filler.

Findings

This method for developing static aeroelastic wind tunnel model with a metal frame and resin covers is feasible, especially for aeroelastic wind tunnel models with complex external aerodynamic shape, which could be accurately constructed based on rapid prototypes in a shorter time with a much lower cost. The developed static aeroelastic aircraft model with a high aspect ratio shows its stiffness distribution in agreement with the design goals, and it is kept in a good condition through the wind tunnel testing at a Mach number ranging from 0.4 to 0.65.

Research limitations/implications

The contact stiffness between the metal frame and resin covers is difficult to calculate accurately even by using finite element analysis; in addition, the manufacturing errors have some effects on the stiffness distribution of aeroelastic models, especially for small-size models.

Originality/value

The design, fabrication and ground testing of aircraft static aeroelastic models presented here provide accurate stiffness and shape stimulation in a cheaper and sooner way compared with that of traditional aeroelastic models. The ground stiffness measurement uses the photogrammetry, which can provide quick, and precise, evaluation of the actual stiffness distribution of a static aeroelastic model. This study, therefore, expands the applications of rapid prototyping on wind tunnel model fabrication, especially for the practical static aeroelastic wind tunnel tests.

Details

Rapid Prototyping Journal, vol. 21 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 18 January 2008

Zhihua Zhou, Dichen Li, Zhengyu Zhang and Junhua Zeng

The purpose of this paper is to develop and present a hybrid design and fabrication method based on rapid prototyping (RP) and electrochemical deposition (ED) techniques to…

1244

Abstract

Purpose

The purpose of this paper is to develop and present a hybrid design and fabrication method based on rapid prototyping (RP) and electrochemical deposition (ED) techniques to fabricate a pressure wind‐tunnel model with complex internal structure and sufficient mechanical strength.

Design/methodology/approach

After offsetting inward by applied coating thickness, the airfoil model was modified with three pairs of deflecting control surfaces and 24 surface pressure taps and internal passages. The stereolithography (SL) prototype components were fabricated on SL apparatus and roughened by chemical treatments. And then metal‐coated SL components of the airfoil model were created by ED technique. After assembling, a hybrid pressure airfoil model was obtained.

Findings

Electrodeposited nickel coating has dramatically improved the overall strength and stiffness of SL parts and the hybrid fabrication method is suitable to construct the wind‐tunnel model with complex internal structure and sufficient mechanical strength, stiffness.

Research limitations/implications

Interface adhesion of SL‐coating is poor even if chemical roughening is applied and the further research is needed.

Originality/value

This method enhances the versatility of using RP in the fabrication of functional models, especially when complex structure with sufficient mechanical properties is considered. Although this paper took an airfoil wind‐tunnel model as an example, it is capable of fabricating other functional components with other rapid prototyping techniques such as FDM, SLS and LOM.

Details

Rapid Prototyping Journal, vol. 14 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 19 July 2024

Zican Chang, Guojun Zhang, Wenqing Zhang, Yabo Zhang, Li Jia, Zhengyu Bai and Wendong Zhang

Ciliated microelectromechanical system (MEMS) vector hydrophones pick up sound signals through Wheatstone bridge in cross beam-ciliated microstructures to achieve information…

95

Abstract

Purpose

Ciliated microelectromechanical system (MEMS) vector hydrophones pick up sound signals through Wheatstone bridge in cross beam-ciliated microstructures to achieve information transmission. This paper aims to overcome the complexity and variability of the marine environment and achieve accurate location of targets. In this paper, a new method for ocean noise denoising based on improved complete ensemble empirical mode decomposition with adaptive noise combined with wavelet threshold processing method (CEEMDAN-WT) is proposed.

Design/methodology/approach

Based on the CEEMDAN-WT method, the signal is decomposed into different intrinsic mode functions (IMFs), and relevant parameters are selected to obtain IMF denoised signals through WT method for the noisy mode components with low sample entropy. The final pure signal is obtained by reconstructing the unprocessed mode components and the denoising component, effectively separating the signal from the wave interference.

Findings

The three methods of empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and CEEMDAN are compared and analyzed by simulation. The simulation results show that the CEEMDAN method has higher signal-to-noise ratio and smaller reconstruction error than EMD and EEMD. The feasibility and practicability of the combined denoising method are verified by indoor and outdoor experiments, and the underwater acoustic experiment data after processing are combined beams. The problem of blurry left and right sides is solved, and the high precision orientation of the target is realized.

Originality/value

This algorithm provides a theoretical basis for MEMS hydrophones to achieve accurate target positioning in the ocean, and can be applied to the hardware design of sonobuoys, which is widely used in various underwater acoustic work.

Details

Sensor Review, vol. 44 no. 5
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 7 March 2017

Yan Hong and Fei Chen

Adaptive reuse of building assets is an important approach to sustainability. Adapting a building for new uses often involves complex factors in the decision-making process…

2013

Abstract

Purpose

Adaptive reuse of building assets is an important approach to sustainability. Adapting a building for new uses often involves complex factors in the decision-making process, particularly in conservation areas. The paper aims to show an evaluation process of the adaptive reuse potential of historic buildings that are subject to change in the Grand Canal area, a world heritage site in Hangzhou, China.

Design/methodology/approach

For this purpose, a model has been established with aggregated views of professionals on the degree to which a variety of factors affect the buildings’ potential for adaptive reuse. The model intends to help prioritise some of the buildings in the area for adaptive reuse, which is important for effective allocation of public resources. Interviews with professionals, analytic hierarchy process and the Delphi method have been used to establish the evaluation model. It is then applied to the Grand Canal area to generate indices for buildings’ adaptive reuse potential and the ranking of priority. The indices are generated through public scoring of historic buildings against the variables and calculated through the model.

Findings

The paper concludes that the evaluation process is an effective way to engage the public in the decision-making process and to balance conflict interests of various stakeholders in the management of historic building assets in conservation areas.

Originality/value

The research has proposed an evaluation model to help set priority of buildings subject to adaptive reuse and to help distribute public fund effectively. It facilitates wide public engagement in the decision-making progress of adaptive reuse of historic buildings.

Details

Facilities, vol. 35 no. 3/4
Type: Research Article
ISSN: 0263-2772

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Article
Publication date: 7 August 2019

Zhengyu Huang, Lingyu Chen, Lianchao Zhang, Shixun Fan and Dapeng Fan

This paper aims to analyze the key factors influencing the synchronization performance of distributed motion control system and to improve the synchronization performance for…

168

Abstract

Purpose

This paper aims to analyze the key factors influencing the synchronization performance of distributed motion control system and to improve the synchronization performance for peripherals control of this system.

Design/methodology/approach

This paper deals with the software synchronization problems of distributed motion control system based on real-time Ethernet. First, combined with communication and control tasks, the key factors affecting synchronization performance of system are analyzed. Then, aiming at key factors and considering the synchronization of system bus, protocol conversion and task scheduling, a software synchronization method based on CANopen protocol and real-time Ethernet is proposed. Finally, the feasibility of this method is verified by establishing distributed motion control system and testing the synchronization performance of terminal control signals of slaves.

Findings

Based on this method, the results show that the synchronization accuracy for peripherals control of all slaves could be about 100 ns.

Practical implications

This research provides high-precision synchronization method, which could lay a foundation for the application of distributed motion control system in the field of assembly automation, such as multi-axis assembly robots control.

Originality/value

In distributed motion control system, many factors affect the synchronization performance. At present, there is no synchronization method that could comprehensively consider these factors. This paper not only analyzes the key factors influencing the synchronization performance of system but also proposes a synchronization method. Therefore, the method proposed in this paper has certain theoretical value and engineering significance.

Details

Assembly Automation, vol. 39 no. 5
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 26 May 2020

Changhai Lin, Zhengyu Song, Sifeng Liu, Yingjie Yang and Jeffrey Forrest

The purpose of this paper is to analyze the mechanism and filter efficacy of accumulation generation operator (AGO)/inverse accumulation generation operator (IAGO) in the…

107

Abstract

Purpose

The purpose of this paper is to analyze the mechanism and filter efficacy of accumulation generation operator (AGO)/inverse accumulation generation operator (IAGO) in the frequency domain.

Design/methodology/approach

The AGO/IAGO in time domain will be transferred to the frequency domain by the Fourier transform. Based on the consistency of the mathematical expressions of the AGO/IAGO in the gray system and the digital filter in digital signal processing, the equivalent filter model of the AGO/IAGO is established. The unique methods in digital signal processing systems “spectrum analysis” of AGO/IAGO are carried out in the frequency domain.

Findings

Through the theoretical study and practical example, benefit of spectrum analysis is explained, and the mechanism and filter efficacy of AGO/IAGO are quantitatively analyzed. The study indicated that the AGO is particularly suitable to act on the system's behavior time series in which the long period parts is the main factor. The acted sequence has good effect of noise immunity.

Practical implications

The AGO/IAGO has a wonderful effect on the processing of some statistical data, e.g. most of the statistical data related to economic growth, crop production, climate and atmospheric changes are mainly affected by long period factors (i.e. low-frequency data), and most of the disturbances are short-period factors (high-frequency data). After processing by the 1-AGO, its high frequency content is suppressed, and its low frequency content is amplified. In terms of information theory, this two-way effect improves the signal-to-noise ratio greatly and reduces the proportion of noise/interference in the new sequence. Based on 1-AGO acting, the information mining and extrapolation prediction will have a good effect.

Originality/value

The authors find that 1-AGO has a wonderful effect on the processing of data sequence. When the 1-AGO acts on a data sequence X, its low-pass filtering effect will benefit the information fluctuations removing and high-frequency noise/interference reduction, so the data shows a clear exponential change trends. However, it is not suitable for excessive use because its equivalent filter has poles at the non-periodic content. But, because of pol effect at zero frequency, the 1-AGO will greatly amplify the low-frequency information parts and suppress the high-frequency parts in the information at the same time.

Details

Grey Systems: Theory and Application, vol. 11 no. 1
Type: Research Article
ISSN: 2043-9377

Keywords

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Book part
Publication date: 3 February 2025

Chandrima Chakraborty and Dipyaman Pal

Abstract

Details

Performance Analysis of the Indian Pharmaceutical Industry: A Global Outlook
Type: Book
ISBN: 978-1-83797-743-7

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Article
Publication date: 9 January 2024

Xiuyun Yang and Qi Han

The purpose of this study is to investigate whether the corporate environmental, social and governance (ESG) performance of enterprise is influenced by the enterprise digital…

1641

Abstract

Purpose

The purpose of this study is to investigate whether the corporate environmental, social and governance (ESG) performance of enterprise is influenced by the enterprise digital transformation. In addition, this study explains how enterprise digital transformation affects ESG performance.

Design/methodology/approach

The sample covers 4,646 nonfinancial companies listed on China’s A-share market from 2009 to 2021. The study adopts the fixed-effects multiple linear regression to perform the data analysis.

Findings

The study finds that enterprise digital transformation has a significant inverted U-shaped impact on ESG performance. Moderate digital transformation can improve enterprise ESG performance, whereas excessive digital transformation will bring new organizational conflicts and increase enterprise costs, which is detrimental to ESG performance. This inverted U-shaped effect is more pronounced in industrial cities, manufacturing industries and enterprises with less financing constraints and executives with financial backgrounds. Enterprise digital transformation mainly affects ESG performance by affecting the level of internal information communication and disclosure, the level of internal control and the principal-agent cost.

Practical implications

The government should take multiple measures to encourage enterprises to choose appropriate digital transformation based on their own production behaviors and development strategies, encourage them to innovate and upgrade their organizational management and development models in conjunction with digital transformation and guide them to use digital technology to improve ESG performance.

Social implications

This study shows that irrational digital transformation cannot effectively improve the ESG performance of enterprises and promote the sustainable development of the country. Enterprises should carry out reasonable digital transformation according to their own development needs and finally improve the green and sustainable development ability of enterprises and promote the sustainable development of society.

Originality/value

This study examines the relationship between enterprise digital transformation and ESG performance. Different from the linear relationship between the two in previous major studies, this study proves the inverse U-shaped relationship between enterprise digital transformation and ESG performance through mathematical theoretical model derivation and empirical test. This study also explores in detail how corporate digital transformation affects ESG performance, as well as discusses heterogeneity at the city, industry and firm levels. It is proposed that enterprises should take into account their own characteristics and carry out reasonable digital transformation according to their development needs.

Details

Sustainability Accounting, Management and Policy Journal, vol. 15 no. 2
Type: Research Article
ISSN: 2040-8021

Keywords

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