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Open Access
Article
Publication date: 21 December 2023

Rafael Pereira Ferreira, Louriel Oliveira Vilarinho and Americo Scotti

This study aims to propose and evaluate the progress in the basic-pixel (a strategy to generate continuous trajectories that fill out the entire surface) algorithm towards…

Abstract

Purpose

This study aims to propose and evaluate the progress in the basic-pixel (a strategy to generate continuous trajectories that fill out the entire surface) algorithm towards performance gain. The objective is also to investigate the operational efficiency and effectiveness of an enhanced version compared with conventional strategies.

Design/methodology/approach

For the first objective, the proposed methodology is to apply the improvements proposed in the basic-pixel strategy, test it on three demonstrative parts and statistically evaluate the performance using the distance trajectory criterion. For the second objective, the enhanced-pixel strategy is compared with conventional strategies in terms of trajectory distance, build time and the number of arcs starts and stops (operational efficiency) and targeting the nominal geometry of a part (operational effectiveness).

Findings

The results showed that the improvements proposed to the basic-pixel strategy could generate continuous trajectories with shorter distances and comparable building times (operational efficiency). Regarding operational effectiveness, the parts built by the enhanced-pixel strategy presented lower dimensional deviation than the other strategies studied. Therefore, the enhanced-pixel strategy appears to be a good candidate for building more complex printable parts and delivering operational efficiency and effectiveness.

Originality/value

This paper presents an evolution of the basic-pixel strategy (a space-filling strategy) with the introduction of new elements in the algorithm and proves the improvement of the strategy’s performance with this. An interesting comparison is also presented in terms of operational efficiency and effectiveness between the enhanced-pixel strategy and conventional strategies.

Details

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

Keywords

Open Access
Article
Publication date: 4 April 2024

Weihua Zhang, Yuanchen Zeng, Dongli Song and Zhiwei Wang

The safety and reliability of high-speed trains rely on the structural integrity of their components and the dynamic performance of the entire vehicle system. This paper aims to…

Abstract

Purpose

The safety and reliability of high-speed trains rely on the structural integrity of their components and the dynamic performance of the entire vehicle system. This paper aims to define and substantiate the assessment of the structural integrity and dynamical integrity of high-speed trains in both theory and practice. The key principles and approaches will be proposed, and their applications to high-speed trains in China will be presented.

Design/methodology/approach

First, the structural integrity and dynamical integrity of high-speed trains are defined, and their relationship is introduced. Then, the principles for assessing the structural integrity of structural and dynamical components are presented and practical examples of gearboxes and dampers are provided. Finally, the principles and approaches for assessing the dynamical integrity of high-speed trains are presented and a novel operational assessment method is further presented.

Findings

Vehicle system dynamics is the core of the proposed framework that provides the loads and vibrations on train components and the dynamic performance of the entire vehicle system. For assessing the structural integrity of structural components, an open-loop analysis considering both normal and abnormal vehicle conditions is needed. For assessing the structural integrity of dynamical components, a closed-loop analysis involving the influence of wear and degradation on vehicle system dynamics is needed. The analysis of vehicle system dynamics should follow the principles of complete objects, conditions and indices. Numerical, experimental and operational approaches should be combined to achieve effective assessments.

Originality/value

The practical applications demonstrate that assessing the structural integrity and dynamical integrity of high-speed trains can support better control of critical defects, better lifespan management of train components and better maintenance decision-making for high-speed trains.

Details

Railway Sciences, vol. 3 no. 2
Type: Research Article
ISSN: 2755-0907

Keywords

Article
Publication date: 9 January 2024

Zeynep Fatma Niğdeli, Funda Gençer and İzzet Yüksek

The purpose of the study is to provide a dataset about geometrical constructions of early Ottoman tombs for conservation studies. Thus, a proposal for the restitution phase of the…

Abstract

Purpose

The purpose of the study is to provide a dataset about geometrical constructions of early Ottoman tombs for conservation studies. Thus, a proposal for the restitution phase of the damaged tombs aims to develop.

Design/methodology/approach

The study is composed of four phases. First, the representative plan and section drawings of early Ottoman Tombs were redrawn; second, a geometrical analysis was made, a proposal table was prepared for the restitution of the damaged tombs; and last, this table was applied to tomb examples and restitution drawings are verified with the original situation of the tombs.

Findings

Early Ottoman tombs may be interpreted through geometric shapes, including the square, circle, triangle, octagon, arsin grid and quadrature systems. The arsin grid system provides information about the position of the domes and the height of the drums and windows. Quadrature establishes the highest point of domes and entrances. The proposal table, developed from the obtained results, facilitated the identification of the original elements, including the dome, drum, window and portal. This information is crucial for conducting further studies on restitution.

Originality/value

The abundance and dispersed nature of tomb structures compared to other architectural designs pose challenges in their scholarly examination. The early Ottoman tombs, which experienced an increase in numbers following the Conquest of Istanbul, serve as the initial expressions and embodiments of novel architectural endeavors. Thus, the determination of design ideas of the early Ottoman tombs sheds light on Ottoman architectural practice, which has remained largely unknown and guided the conservation studies of the tombs that have lost their integrity and originality.

Details

Open House International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0168-2601

Keywords

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