Semi-active inerters using magnetorheological fluid: a feasibility study

An inerter is a mechanical analogue to a capacitor, where the force across the device is proportional to relative, rather than absolute, acceleration. This concept can offer attractive performance in a wide variety of engineering vibration problems, because the engineer can tune the device without dramatically increasing the physical mass of the structure. Consequently, there have been many studies over the last two decades that have explored their application to bridge vibrations, seismic isolation of tall buildings, vehicle suspensions, and other engineering problems. Several configurations of inerter systems have been proposed, typically involving the inerter in a vibration absorber, or by using the inerter as part of an isolation system. However, to date there have been limited studies that have explored the combination of inerters with semi-active devices such as magnetorheological fluid dampers. Furthermore, because one manifestation of inerters involves the use of hydraulic fluid, it is possible for magnetorheological effects to be integrated into the inerter itself. The present study investigates the feasibility of this approach for practical scenarios. A quasi-static model is developed, combining an existing model of a fluid inerter with simplified models for magnetorheological fluids. The trade-off between damping performance and inerter performance is explored. The model is then used in a case study, where its potential use in a control strategy known as a parallel-layout inerter damper is investigated

Multiple-input, multiple-output modal testing of a Hawk T1A aircraft: A new full-scale dataset for structural health monitoring

The use of measured vibration data from structures has a long history of enabling the development of methods for inference and monitoring. In particular, applications based on system identification and structural health monitoring have risen to prominence over recent decades and promise significant benefits when implemented in practice. However, significant challenges remain in the development of these methods. The introduction of realistic, full-scale datasets will be an important contribution to overcoming these challenges. This paper presents a new benchmark dataset capturing the dynamic response of a decommissioned BAE Systems Hawk T1A. The dataset reflects the behaviour of a complex structure with a history of service that can still be tested in controlled laboratory conditions, using a variety of known loading and damage simulation conditions. As such, it provides a key stepping stone between simple laboratory test structures and in-service structures. In this paper, the Hawk structure is described in detail, alongside a comprehensive summary of the experimental work undertaken. Following this, key descriptive highlights of the dataset are presented, before a discussion of the research challenges that the data present. Using the dataset, non-linearity in the structure is demonstrated, as well as the sensitivity of the structure to damage of different types. The dataset is highly applicable to many academic enquiries and additional analysis techniques which will enable further advancement of vibration-based engineering techniques

Differences in consumer decision-making styles among selected south-east European countries

Fast changes in retailing and complex consumer decision-making processes have increased the need for additional investigation of differences and similarities in consumer decision-making styles (CDMS) in various countries. This paper tests the reliability and validity of Sproles and Kendall’s Consumer Style Inventory (CSI) instrument, identifies and compares CDMS in Croatia, Bosnia and Herzegovina and Macedonia (FYR). Data obtained from surveys conducted among university students in observed countries (n = 1.206) were analysed by using exploratory and confirmatory factor analyses and the analysis of variance (ANOVA). The results provided support for six factors, which means that the original US eight-model cannot be fully applied in this region. Croatian consumers are the least brand-conscious and novelty-fashion conscious. Macedonian consumers are the most quality-conscious, brand-conscious, novelty-fashion conscious, recreational shopping conscious and brand-loyal, while Bosnian consumers are the most confused by overchoice. The traits of price consciousness and impulsiveness were not tested because of lack of reliability among items. The paper provides guidelines for marketers on how to position and more effectively advertise their products and services in analysed countries

Measuring Corporate Social Responsibility in tourism: Development and validation of an efficient measurement scale in the hospitality industry.

ABSTRAC: This article aims at developing an efficient measurement scale for corporate social responsibility in the tourism industry, given the contextual character that is recognized in the practice of this construct. Indicators were generated on the basis of a literature review and qualitative research. To assess the reliability and validity, first- and second-order confirmatory factor analysis were carried out. Results show a multidimensional structure of this construct—including economic, social, and environmental issues. This study contributes to the advancement of knowledge in the field of social responsibility through its practical application regarding concepts of sustainable development which have mainly been theoretical

The domain relationship diagram: clarifying and communicating stakeholder perspectives in interconnected digital twin architectures

Conventional conceptions of digital twins include an implicit assumption of a single entity or organisation responsible for --- and interested in --- both the physical and digital twin. In many areas where digital twins can provide value, especially those relating to policy and public services, this cannot be assumed. Digital twins have been proposed and used for transport and traffic, policy, crises response, smart cities, health care, and logistics – all areas in which multiple systems interact, and responsibility is split between many stakeholders. Co-operation and collaboration between these stakeholders is essential for the successful design and implementation of digital twins in such areas. However, this is hampered by a lack of shared vision and understanding, especially in the early phases of a project. In this paper we propose the domain relationship diagram (DRD) as a framework for exploring the beliefs and assumptions that stakeholders bring to projects involving interconnection of digital twins. We demonstrate how the DRD can be used as a collaborative tool for exploring the relationships different stakeholders have to one another, their interest and responsibilities for the physical and virtual domains within a cyber-physical ecosystem, and the data handling and sharing requirements of all involved. While the DRD is applicable to any multi-stakeholder digital twin project, in this paper we present it in the context of two different use cases relating to public policy. The first use case is that of a transport crisis response digital twin, based on work sponsored by the Department for Transport in the UK. The second use case relates to a climate and energy policy digital twin, linking to the European Space Agency’s DestinE digital twin. In both examples, we demonstrate how the use of the DRD brings clarity to a project and can be used as a basis to define specifications for the digital twin components

Modular deployment of microprocessor-controlled data acquisition and control within a digital twin

One major component of building management is the understanding of the current state of the system, typically using sensor measurements. To achieve this, many building managers are interested in the deployment of a digital twin for each building that allows for remote inquiries. However, many commercial data acquisition systems use proprietary connections or data formats putting a large barrier for interoperability between sensors and digital twins. To remove this barrier, this work develops a transparent data acquisition system using microprocessors and the remote connection to this system through a python-based remote digital twin operational platform. The use of microprocessors allows for nearly complete control of the data processing from the analogue to digital converter, data sampling, and data recording. There are many possibilities to process this data, so this paper focuses on identifying the various possibilities and demystifying this computer science topics for engineers. To access this data, a remote connection allows for multiple users to simultaneously access the current operational data. Using an interface, such as the digital twin operational platform, reduces the required knowledge to promote a multi-disciplinary culture through shared data within the digital twin

Digital Twinning for Crisis response in Transport-based Scenarios: Research Outcomes: DTBOC - Digital Twins Beyond Observed Capabilities: Summary Report

The findings in this report are based primarily on data collected from two sandpit events which brought together over 100 participants from research institutions, government, and industry. The findings are also supported by desk-based research, including a comprehensive literature review, and by the researchers’ own experience and judgement. Feasibility analysis was conducted on 24 crisis resilience digital twin (CRDT) value propositions, considering technological, social, legal, and economic factors, as well as delivery timescales. Digital twins are virtual models of objects, systems, or processes, connected to their real-world counterpart by a 2-way flow of right-time data, meaning they mimic the counterparts in all aspects. This project focussed on digital twins for crisis response and resilience in the context of transport related risks