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1 – 10 of over 2000
Article
Publication date: 26 April 2023

Kenneth Butcher and Chachaya Yodsuwan

The purpose of this paper is to discuss the current status of experimental research within hospitality and tourism. This paper further aims to develop practical ideas for…

Abstract

Purpose

The purpose of this paper is to discuss the current status of experimental research within hospitality and tourism. This paper further aims to develop practical ideas for enhancing the adoption of a cause and effect mindset in researchers.

Design/methodology/approach

A mini-review of the level of experimental designs and best-practice ideas published by the top 12 journals in hospitality and tourism over a five-year period was conducted.

Findings

Although the absolute number of experimental studies is growing, the ratio of experimental studies to overall publications remains low at 6.4%. To increase the take-up of experimental design, a broader typology of field experiments is presented. Practical steps to increase causal reality are provided under the categories of purpose; scenario development; scenario testing; and sample characteristics.

Research limitations/implications

The methodological advances suggested in this paper can contribute to more robust theory development and testing. The recommendations offer guidance to a new generation of researchers seeking to add causal value to their studies, researchers collaborating with scholars from other discipline areas and hospitality managers seeking stronger evidence of cause and effect.

Originality/value

This paper identifies key obstacles to the take-up of experimental design and the contemporary status of experimental design. A novel typology of five experimental designs that distinguish the difference between experimental and correlational designs in terms of explanatory power is presented, together with a comprehensive list of best practice suggestions to increase causal reality in scenario design.

Details

International Journal of Contemporary Hospitality Management, vol. 36 no. 1
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 3 October 2023

Roberto Junior Algarín Roncallo, Luis Lisandro Lopez Taborda and Diego Guillen

The purpose of this research is present an experimental and numerical study of the mechanical properties of the acrylonitrile butadiene styrene (ABS) in the additive manufacturing…

Abstract

Purpose

The purpose of this research is present an experimental and numerical study of the mechanical properties of the acrylonitrile butadiene styrene (ABS) in the additive manufacturing (AM) by fused filament fabrication (FFF). The characterization and mechanical models obtained are used to predict the elastic behavior of a prosthetic foot and the failure of a prosthetic knee manufactured with FFF.

Design/methodology/approach

Tension tests were carried out and the elastic modulus, yield stress and tensile strength were evaluated for different material directions. The material elastic constants were determined and the influence of infill density in the mechanical strength was evaluated. Yield surfaces and failure criteria were generated from the tests. Failures over prosthetic elements in tridimensional stresses were analyzed; the cases were evaluated via finite element method.

Findings

The experimental results show that the material is transversely isotropic. The elasticity modulus, yield stress and ultimate tensile strength vary linearly with the infill density. The stresses and the failure criteria were computed and compared with the experimental tests with good agreement.

Practical implications

This research can be applied to predict failures and improve reliability in FFF or fused deposition modeling (FDM) products for applications in high-performance industries such as aerospace, automotive and medical.

Social implications

This research aims to promote its widespread adoption in the industrial and medical sectors by increasing reliability in products manufactured with AM based on the failure criterion.

Originality/value

Most of the models studied apply to plane stress situations and standardized specimens of printed material. However, the models applied in this study can be used for functional parts and three-dimensional stress, with accuracy in the range of that obtained by other researchers. The researchers also proposed a method for the mechanical study of fragile materials fabricated by processes of FFF and FDM.

Article
Publication date: 5 December 2023

S. Rama Krishna, J. Sathish, Talari Rahul Mani Datta and S. Raghu Vamsi

Ensuring the early detection of structural issues in aircraft is crucial for preserving human lives. One effective approach involves identifying cracks in composite structures…

Abstract

Purpose

Ensuring the early detection of structural issues in aircraft is crucial for preserving human lives. One effective approach involves identifying cracks in composite structures. This paper employs experimental modal analysis and a multi-variable Gaussian process regression method to detect and locate cracks in glass fiber composite beams.

Design/methodology/approach

The present study proposes Gaussian process regression model trained by the first three natural frequencies determined experimentally using a roving impact hammer method with crystal four-channel analyzer, uniaxial accelerometer and experimental modal analysis software. The first three natural frequencies of the cracked composite beams obtained from experimental modal analysis are used to train a multi-variable Gaussian process regression model for crack localization. Radial basis function is used as a kernel function, and hyperparameters are optimized using the negative log marginal likelihood function. Bayesian conditional probability likelihood function is used to estimate the mean and variance for crack localization in composite structures.

Findings

The efficiency of Gaussian process regression is improved in the present work with the normalization of input data. The fitted Gaussian process regression model validates with experimental modal analysis for crack localization in composite structures. The discrepancy between predicted and measured values is 1.8%, indicating strong agreement between the experimental modal analysis and Gaussian process regression methods. Compared to other recent methods in the literature, this approach significantly improves efficiency and reduces error from 18.4% to 1.8%. Gaussian process regression is an efficient machine learning algorithm for crack localization in composite structures.

Originality/value

The experimental modal analysis results are first utilized for crack localization in cracked composite structures. Additionally, the input data are normalized and employed in a machine learning algorithm, such as the multi-variable Gaussian process regression method, to efficiently determine the crack location in these structures.

Details

International Journal of Structural Integrity, vol. 15 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 3 April 2023

Dangshu Wang, Jiaan Yi, Luwen Song, Xuan Deng, Xinxia Wang and Zhen Dong

This paper aims to solve the problems of large hard switching loss and unclear resonant parameter design in the existing inverter power supply topology.

Abstract

Purpose

This paper aims to solve the problems of large hard switching loss and unclear resonant parameter design in the existing inverter power supply topology.

Design/methodology/approach

This paper proposes a simple and reliable two-stage isolated inverter composed of series quasi-resonant push-pull and external freewheeling diode full-bridge inverter. The power supply topology is analyzed, the topology mode is analyzed, the mathematical model of the converter is established and the DC gain of the converter is deduced. The relationship between the load and the output gain of the resonant tank is presented, a new resonant parameter design method is proposed, and the parameter design of the resonant element of the converter is clarified.

Findings

The resonant components of the converter are designed according to the proposed resonant parameter design method, and the correctness of the method is verified by simulation and the development and testing of a 500 W experimental prototype. After experimental tests, the peak efficiency of the experimental prototype can reach 94%. Because the experimental prototype achieves soft switching, the heat generation of the switch is greatly reduced, so the heavy heat sink is removed, and the volume is reduced by about 30% compared with the traditional power supply, and the total harmonic distortion of the output voltage is about 2%.

Originality/value

The feasibility of the scheme is verified by experiments, which is of great significance for improving the efficiency of the inverter power supply and parameter optimization.

Details

Circuit World, vol. 50 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 11 January 2024

Ahmed Ashteyat, Ala Taleb Obaidat, Yasmeen Taleb Obeidat and Ahmad Bani Awwad

The paper aims to introduces an experimental work to investigate the torsional behavior of reinforced concrete (RC) beams strengthened by near-surface mounted (NSM) carbon…

18

Abstract

Purpose

The paper aims to introduces an experimental work to investigate the torsional behavior of reinforced concrete (RC) beams strengthened by near-surface mounted (NSM) carbon fiber-reinforced polymer (CFRP) ropes.

Design/methodology/approach

In this research, nine rectangular RC beams of 250 mm × 300 mm cross-section and 1,600 mm in length were constructed and tested considering the studied parameters. These parameters include the length of the CFRP rope, the orientation of the CFRP rope, the arrangement of longitudinal and the scheme of NSM-CFRP ropes.

Findings

In comparison to control specimens, the results demonstrate a considerable improvement in the torsional response of RC beams strengthened with the CFRP rope. Additionally, specimens strengthened with 90° vertical ropes increase torsional moment capacity more efficiently than specimens strengthened with 45° inclined ropes since the stress concentration leads to premature debonding of the CFRP rope. Whereas RC beams' ability to withstand torsional moments is reduced as the distance between reinforcing CFRP ropes is increased. According to test results, adding CFRP ropes to RC beams' bottoms had a slightly positive impact on torsional response.

Originality/value

This paper fulfills an identified need to study how the using of the CFRP rope is effective in strengthening RC beam subjected to torsion moment.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 15 February 2024

Saliq Shamim Shah, Daljeet Singh, Jaswinder Singh Saini and Naveen Garg

This paper aims to study the design and characterization of a 3D printed tetrakaidecahedron cell-based acoustic metamaterial. At present, the mitigation of low-frequency noise…

Abstract

Purpose

This paper aims to study the design and characterization of a 3D printed tetrakaidecahedron cell-based acoustic metamaterial. At present, the mitigation of low-frequency noise involves the utilization of spatially demanding materials for the absorption of sound. These materials lack the ability for targeted frequency control adjustments. Hence, there is a requirement for an approach that can effectively manage low-frequency noise using lightweight and durable materials.

Design/methodology/approach

The CAD model was created in SolidWorks and was manufactured using the Digital Light Processing (DLP) 3D printing technique. Experimental study and numerical simulations examined the metamaterial’s acoustic absorption. An impedance tube with two microphones was used to determine the absorption coefficient of the metamaterial. The simulations were run in a thermoviscous module.

Findings

The testing of acoustic samples highlighted the effects of geometric parameters on acoustic performance. Increment of the strut length by 0.4 mm led to a shift in response to a lower frequency by 500 Hz. Peak absorption rose from 0.461 to 0.690 as the strut diameter was increased from 0.6 to 1.0 mm. Increasing the number of cells from 8 to 20 increased the absorption coefficient and lowered the response frequency.

Originality/value

DLP 3D printing technique was used to successfully manufacture tetrakaidecahedron-based acoustic metamaterial samples. A novel study on the effects of geometric parameters of tetrakaidecahedron cell-based acoustic metamaterial on the acoustic absorption coefficient was conducted, which seemed to be missing in the literature.

Open Access
Article
Publication date: 28 February 2024

Luke Mizzi, Arrigo Simonetti and Andrea Spaggiari

The “chiralisation” of Euclidean polygonal tessellations is a novel, recent method which has been used to design new auxetic metamaterials with complex topologies and improved…

Abstract

Purpose

The “chiralisation” of Euclidean polygonal tessellations is a novel, recent method which has been used to design new auxetic metamaterials with complex topologies and improved geometric versatility over traditional chiral honeycombs. This paper aims to design and manufacture chiral honeycombs representative of four distinct classes of 2D Euclidean tessellations with hexagonal rotational symmetry using fused-deposition additive manufacturing and experimentally analysed the mechanical properties and failure modes of these metamaterials.

Design/methodology/approach

Finite Element simulations were also used to study the high-strain compressive performance of these systems under both periodic boundary conditions and realistic, finite conditions. Experimental uniaxial compressive loading tests were applied to additively manufactured prototypes and digital image correlation was used to measure the Poisson’s ratio and analyse the deformation behaviour of these systems.

Findings

The results obtained demonstrate that these systems have the ability to exhibit a wide range of Poisson’s ratios (positive, quasi-zero and negative values) and stiffnesses as well as unusual failure modes characterised by a sequential layer-by-layer collapse of specific, non-adjacent ligaments. These findings provide useful insights on the mechanical properties and deformation behaviours of this new class of metamaterials and indicate that these chiral honeycombs could potentially possess anomalous characteristics which are not commonly found in traditional chiral metamaterials based on regular monohedral tilings.

Originality/value

To the best of the authors’ knowledge, the authors have analysed for the first time the high strain behaviour and failure modes of chiral metamaterials based on Euclidean multi-polygonal tessellations.

Details

Rapid Prototyping Journal, vol. 30 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 25 January 2024

Manman Li, Qing Bao, Sumin Lei, Linlin Xing and Shu Gai

The service environment of urban polyethylene (PE) pipes has a crucial influence on their long-term safety and performance. Based on the application and structural performance…

Abstract

Purpose

The service environment of urban polyethylene (PE) pipes has a crucial influence on their long-term safety and performance. Based on the application and structural performance analysis of PE pipe failure cases, this study aims to investigate the impact of organic substances in the soil on the aging behavior of PE pipes by designing organic solutions with different concentrations, which are based on the composition of organic substances in the soil environment, and periodic immersion tests.

Design/methodology/approach

Soil samples in the vicinity of the failed pipes were analyzed by gas chromatography-mass spectrometry, sensitive organic substances were screened and soaking solutions of different concentrations were designed. After the soaking test, the PE pipe samples were analyzed using differential scanning calorimetry, Fourier-transform infrared spectroscopy and other testing methods.

Findings

The performance difference between the outer surface and the middle of the cross section of PE pipes highlights the influence of the soil service environment on their aging. Different organic solutions can have varying impacts on the aging behavior of PE pipes when immersed. For instance, when exposed to amine organic solutions, PE pipes may have an increased weight and decreased material yield strength, although there is no reduction in their thermal or oxygen stability. On the contrary, when subjected to ether organic solutions, the surface of PE pipe specimens may be affected, leading to a reduction in material fracture elongation and a decrease in their thermal and oxygen stability. Furthermore, immersion in either amine or ether organic solutions may result in the production of hydroxyl and other aging groups on the surface of the material.

Originality/value

Understanding the potential impact of organic substances in the soil environment on the aging of PE pipe ensures the long-term performance and safety of urban PE pipe. This research approach will provide valuable insights into improving the durability and reliability of urban PE pipes in soil environments.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 27 September 2022

Chafika Ali Ahmed, Abdelmadjid Si Salem, Souad Ait Taleb and Kamal Ait Tahar

This paper aims to investigate the experimental behavior and the reliability of concrete columns repaired using fiber-reinforced polymers (FRPs) under axial compression loading…

Abstract

Purpose

This paper aims to investigate the experimental behavior and the reliability of concrete columns repaired using fiber-reinforced polymers (FRPs) under axial compression loading. The expression of the ultimate axial resistance was assessed from the experimental data of damaged concrete cylinders repaired by externally bonded double-FRP spiral strips.

Design/methodology/approach

The tested columns bearing capacity mainly depends of the elasticity modulus of both damaged and undamaged concrete have been considered in addition to the applied load and the cylinder diameter as random variables in the expression of the failure criterion. The reliability indicators were assessed using first order second moment method.

Findings

The emphasized test results, statistically fitted show that the strength has been retrofitted for all repaired specimens whatever the degree of initial damage. However, the gain in axial strength is inversely proportional to the degree of damage.

Originality/value

The efficiency of a new FRP repair procedure using double-spiral strips was studied. This research provides a technical and economical solution for retrofitting existing concrete columns. Finally, the random character of the variables that govern the studied system shows the accuracy and safety of the proposed original design.

Details

World Journal of Engineering, vol. 21 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 29 March 2024

Hubannur Seremet and Nazim Babacan

This paper aims to examine the static compression characteristics of cell topologies in body-centered cubic with vertical struts (BCCZ) and face-centered cubic with vertical…

Abstract

Purpose

This paper aims to examine the static compression characteristics of cell topologies in body-centered cubic with vertical struts (BCCZ) and face-centered cubic with vertical struts (FCCZ) along with novel BCCZZ and FCCZZ lattice structures.

Design/methodology/approach

The newly developed structures were obtained by adding extra interior vertical struts into the BCCZ and FCCZ configurations. The samples, composed of the AlSi10Mg alloy, were fabricated using the selective laser melting (SLM) additive manufacturing technique. The specific compressive strength and failure behavior of the manufactured lattice structures were investigated, and comparative analysis among them was done.

Findings

The results revealed that the specific strength of BCCZZ and FCCZZ samples with 0.5 mm strut diameter exhibited approximately a 23% and 18% increase, respectively, compared with the BCCZ and FCCZ samples with identical strut diameters. Moreover, finite element analysis was carried out to simulate the compressive response of the lattice structures, which could be used to predict their strength and collapse mode. The findings showed that while the local buckling of lattice cells is the major failure mode, the samples subsequently collapsed along a diagonal shear band.

Originality/value

An original and systematic investigation was conducted to explore the compression properties of newly fabricated lattice structures using SLM. The results revealed that the novel FCCZZ and BCCZZ structures were found to possess significant potential for load-bearing applications.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

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