Performance of traditional railway structure depends significantly on the behaviour of its support layers, particularly the ballast. This layer's rock particles are selected to ensure high mechanical strength, but traffic and mechanical maintenance break and wear the particles. Consequently, the layer incurs permanent deformations that degrade its strength and increase deformability and permeability. Particle physical characteristics, in particular those related to size and shape, influence their fragmentation and wear and must be studied accordingly. In addition, structural numerical models that represent individual particles, such as the discrete element method, have been increasingly used to model the infrastructure and therefore detailed geometrical characterization in the form of 3D digital models of the particles are necessary. This work contributes to this goal by investigating a contact-based cost-effective method that digitizes particle form and allows the determination of their geometric parameters. This method is described, compared with well-established laser scanning technique and then applied to study degradation of particles in Los Angeles and microDeval fragmentation tests.
The goal of this paper is to simulate the interaction of stress waves and rock fractures in a particle micromechanical model. Stress waves travelling in fractured rock masses are slowed down and attenuated by natural heterogeneities, voids, microcracks and, above all, by faults and fractures. Considerable laboratory and theoretical investigation have uncovered the major aspects of this phenomenon, but models that cover the core mechanisms of the wave propagation in rock masses are necessary to investigate aspects of wave-fracture interaction, which are not completely clear, and in the future simulate full-scale real problems. The micromechanical model is based on the particle discrete element model that reproduces rock through a densely packed non-structured assembly of 2D disks with point contacts. The model of a hard rock core is developed and an irregular rock joint is generated at midheight. A new contact constitutive model is applied to the particles in the joint walls. Numerical static joint compression tests are performed and a typical hyperbolic stress-displacement curve is obtained. Conditions for good quality wave transmission through non-jointed unorganized particulate media are determined, hybrid static-dynamic boundary conditions are established and plane waves are emitted into the compressed joint. The transmitted and reflected waves are extracted and analysed. Joint dynamic stiffness calculated according to the hypotheses of the Displacement Discontinuity Theory shows to increase with the static joint compression until the joint is completely closed. Still in its early stages of application, this rock micromechanical model enables the joint behaviour under static and dynamic loading to be analysed in detail. Its advantages are the reproduction of the real mechanics of contact creation, evolution and destruction and the possibility of visualizing in detail the joint geometry changes, which is hard to accomplish in the laboratory.
This research work uses a simplified approach to combine location information from a beacon’s propagation signal interaction with a mobile device sensor (accelerometer and gyroscope) with local building information to give real-time location and guidance to a user inside a building. This is an interactive process with visualisation information that can help user’s orientation inside unknown buildings and the data stored from different users can provide useful information about users’ movements inside a public building. Beacons installed on the building at specific pre-defined positions emit signals that give a geographic position with an associated imprecision, related with Bluetooth’s range. This uncertainty is handled by building layout and users’ movement in a developed system that maps users’ position, gives guidance, and stores user movements. This system is based on an App (Find Me!) for Android OS (Operating System) which captures the Bluetooth Low Energy (BLE) signal coming from the beacon(s) and shows, through a map, the location of the user’s smartphone and guide him to the desired destination. Also, the beacons can deliver relevant context information. The application was tested by a panel of new and habitual campus users against traditional wayfinding alternatives yielding navigation times about 30% smaller, respectively.
In this research work, we present an IoT solution to environment variables using a LoRa transmission technology to give real-time information to users in a Things2People process and achieve savings by promoting behavior changes in a People2People process. These data are stored and later processed to identify patterns and integrate with visualization tools, which allow us to develop an environmental perception while using the system. In this project, we implemented a different approach based on the development of a 3D visualization tool that presents the system collected data, warnings, and other users’ perception in an interactive 3D model of the building. This data representation introduces a new People2People interaction approach to achieve savings in shared spaces like public buildings by combining sensor data with the users’ individual and collective perception. This approach was validated at the ISCTE-IUL University Campus, where this 3D IoT data representation was presented in mobile devices, and from this, influenced user behavior toward meeting campus sustainability goals.
Energy consumption in buildings depends on the local climate, building characteristics, and user behavior. Focusing on user interaction, this research work developed a novel approach to monitoring and interaction with local users by providing in situ context information through graphic descriptions of energy consumption and indoor/outdoor environment parameters: temperature, luminosity, and humidity, which are routinely measured in real-time and stored to identify consumption patterns and other savings actions. To involve local users, collected data are represented in 3D color representation using building 3d models. A simplified color scale depicts environmental comfort (low/comfortable/high temperature/relative humidity) and energy consumption (above/below usual patterns). We found that these indices induced user commitment and increased their engagement and participation in saving actions like turning off lights and better management of air conditioning systems.
This research work uses a simplified approach to combine location information from beacons propagation signal interaction with a mobile device with local building information to give real-time location and guidance to a user inside a building. This is an interactive process with visualisation information that can help user's orientation inside unknown buildings and the data stored from different users can provide useful information about users movements inside a public building. Beacons installed on the building at specific pre-defined position emit signals that give a geographic position with an associated imprecision, related with Bluetooth's range. This uncertainty is handled by building layout and users' movement in a developed system that maps users' position, gives guidance and store user movements. This system is based on an App (Find Me!) for Android OS (Operating System) which captures the Bluetooth Low Energy (BLE) signal coming from the beacon(s) and shows, through a map, the location of the user 's smartphone and guide him to the desired destination. Also, the beacons can deliver relevant context information. The application was tested by a panel of new and habitual campus users against traditional wayfinding alternatives yielding navigation times about 30% smaller, respectively.
Vitruvius FabLab -IUL I In nt tr ro od du uc ct ti io on n Over the past decades, the development of new technologies and the emergence of sustainable/integrated digital tools for visualization, representation and fabrication have played crucial roles in architectural design, as a new paradigm at various levels: education, research and architectural practice. The digital revolution has transformed not only the process of architectural thinking but also the making. Architecture schools around the world are creating digital fabrication laboratories to provide their students with the skills to support new learning processes, scientific innovation and development linked to architectural practice and the building industry. Digital technologies have released a multiplicity of new career opportunities for graduates and advanced architectural education. Digital methods enable architects to create complex parametric modeling geometries; generate construction information directly from design; test its performance virtually and physically; and produce full-scale models of their designs. Thus, it has been necessary to introduce new architectural curricula in academia and new strategies to approach technology, implement digital thinking, and foster collaborative environments and digital methods. The main goal has been to explore the new digital technologies and their contribution to solving some of the challenges presented to society and architecture. Social responsibility requires greater sensitivity to innovation. Digital design sensibility must encompass the school culture [Cheng 2003]. The progress of architectural practice
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.