Now showing 1 - 10 of 15
  • Publication
    An experimental investigation into span length effect in composite CFS and timber-based flooring systems
    Cold-formed steel (CFS) panelised built-offsite modern methods of construction offer economy of scale, high precision, reduction in construction waste and a more streamlined manufacturing and construction process, compared to traditional construction. Floors made with CFS joists and timber-based flooring systems, often jointed using screws and structural adhesives, have become increasingly popular. Nevertheless, the beneficial effect of the timber flooring on overall floor structural behaviour is often ignored in design due to limited understanding of CFS joist-timber board interaction and the effect of various influencing parameters. This article investigates, experimentally, the structural performance of such composite floors. This paper presents eighteen large scale bending tests of CFS composite floors and five pushout tests to investigate the effect of span length on composite action. The results demonstrate that a high degree of composite action can be achieved when both screws and adhesives are utilised, resulting in around 40% increase in flexural stiffness when compared to joist performance without boards. This can lead to a more efficient and sustainable design of CFS joisted floors. The results also show that further research is needed to extend existing design equations to cover short span lengths.
  • Publication
    Academic Advising in Civil Engineering: design and evaluation of a hybrid model
    A project to formalise and expand Academic Advising has been implemented at the UCD Civil Engineering School. The goals of this project were twofold: on the one hand, it aimed at training faculty members in Academic Advising roles and providing them with the necessary resources. On the other hand, the project sought to expand student interaction, in particular by engaging students informally in order to build a rapport between them and the academic advisors that we expect will bring long term benefits. The resulting model combines elements of both the prescriptive, e.g., formal training, informative talks on key topics, and developmental approaches, e.g., coffee mornings for students and faculty members. The evaluation of the project was carried out through questionnaires and focus groups. It highlighted very positive feedback from the students, who find these new lines of communication with the academic staff to be useful and productive.
      132Scopus© Citations 2
  • Publication
    Aligning Learning Outcomes to Improve Communication and Learning Skills in an Interdisciplinary Problem-Based Learning Environment
    Engineers require the skill of effective communication and interaction with architects to be successful throughout their professional career. While the relationship between architects and structural engineers develops during their professional career, it is often overlooked during their undergraduate education. This paper presents learning strategies to improve the communication between engineering and architecture students as well as the awareness of the others’ profession. The strategy of aligning learning outcomes to develop communication skills and prevent reproductive learning are applied in four continuous assessment problem-based learning (PBL) submissions. The strategies were applied in the experimental setting of a Stage 1 undergraduate module jointly offered to architecture and general entry engineering students at the School of Civil Engineering, University College Dublin. Results from surveys showed the students enjoyed the module and had a high level of understanding of the other profession at the end of the module. The students identified an improvement in their own communication skills as a result of the module.
  • Publication
    Monitoring the health of bridges using accelerations from a fleet of vehicles without knowing individual axle weights
    (Taylor and Francis, 2023-04-16) ; ;
    This paper proposes a new indirect bridge structural health monitoring concept that uses acceleration data from a fleet of different vehicles with unknown weights. When a vehicle passes the bridge, the vertical displacement under its axles can be inferred from its vertical accelerations. This displacement, termed the “apparent profile”, contains two components: bridge profile elevations and bridge deflections under the axle. The two deflection component can be used to find the moving reference influence function (MRIF), defined as the deflection at a (moving) reference point due to a unit load at another point, moving at the same speed. The MRIF can be found when all axle weights are known. In this paper, a new method is proposed to obtain road profile and bridge health condition from the vehicle acceleration, without knowing individual axle weights. Numerical simulation results show that the inferred bridge profile changes when the bridge health condition changes. The difference can be used as an indicator of bridge damage and is illustrated here through an example of bearing damage.
  • Publication
    Developing interdisciplinary understanding and dialogue between Engineering and Architectural students: design and evaluation of a problem-based learning module
    (Taylor & Francis, 2020-09-30) ;
    Engineers and Architects require effective communication and interdisciplinary team working to be successful throughout their career which, is often overlooked during formal undergraduate education. The purpose of this paper is to disseminate the novel design and evaluation of a module on communication and interdisciplinary team working in the combined teaching of undergraduate Engineering and Architecture students. An Interdisciplinary Problem Based Learning (IPBL) approach is used and the theoretical construct for this work is the application of dialogical theory to the shared habitus between engineers and architects. The constructivist theory of learning was employed in the design and delivery of this module. It is an action research pedagogical intervention to support the improvement in the teaching and learning of communications and teamwork between architects and engineers. Feedback shows students identified improvement in their communication and teamwork skills at the end of the module.
      381Scopus© Citations 8
  • Publication
    A Novel Acceleration-Based Moving Force Identification Algorithm to Detect Global Bridge Damage
    This paper presents a new moving force identification (MFI) algorithm that uses measured accelerations to infer applied vehicle forces on bridges. Previous MFI algorithms use strain or deflection measurements. Statistics of the inferred forces are used in turn as indicators of global bridge damage. The new acceleration-based MFI algorithm (A-MFI) is validated through numerical simulations with a coupled vehicle-bridge dynamic interaction model programmed in MATLAB. A focussed sensitivity study suggests that results are sensitive to the accuracy of the vehicle velocity data. The inferred Gross Vehicle Weight (GVW), calculated by A-MFI, is proposed as the bridge damage indicator. A real weigh-in-motion database is used with a simulation of vehicle/bridge interaction, to validate the concept. Results show that the standard deviation of inferred GVWs has a good correlation with the global bridge damage level
      10Scopus© Citations 9
  • Publication
    Laboratory investigation of a bridge scour monitoring method using decentralized modal analysis
    Scour is a significant issue for bridges worldwide that influences the global stiffness of bridge structures and hence alters the dynamic behaviour of these systems. For the first time, this article presents a new approach to detect bridge scour at shallow pad foundations, using a decentralized modal analysis approach through re-deployable accelerometers to extract modal information. A numerical model of a bridge with four simply supported spans on piers is created to test the approach. Scour is modelled as a reduction in foundation stiffness under a given pier. A passing half-car vehicle model is simulated to excite the bridge in phases of measurement to obtain segments of the mode shape using output-only modal analysis. Two points of the bridge are used to obtain modal amplitudes in each phase, which are combined to estimate the global mode shape. A damage indicator is postulated based on fitting curves to the mode shapes, using maximum likelihood, which can locate scour damage. The root mean square difference between the healthy and scoured mode shape curves exhibits an almost linear increase with increasing foundation stiffness loss under scour. Experimental tests have been carried out on a scaled model bridge to validate the approach presented in this article.
    Scopus© Citations 21  78
  • Publication
    Wavelet-based operating deflection shapes for locating scour-related stiffness losses in multi-span bridges
    Scour erosion poses a significant risk to bridge safety worldwide and affects the stiffness of the soil-foundation system, resulting in global changes in the dynamic behavior of the bridges. In this paper, a new approach to detect scour at multiple locations is proposed, using wavelet-based Operating Deflection Shape (ODS) amplitudes. A numerical model of a bridge with four simply supported spans resting on piers is used to test the approach. Scour is modelled as a reduction in vertical foundation stiffness under one or multiple bridge piers. A fleet of passing trucks, modelled as half-car vehicles, are used to excite the bridge to enable structural accelerations be calculated at each support. The approach is shown to be effective with acceleration measurements at each support location in a multi-span bridge. Using a fleet of passing vehicles, the temporal accelerations measured at each support are averaged and transformed into the frequency–spatial domain, in order to estimate the wavelet-based ODS for a given scour case. A damage indicator is postulated based on differences between the ODS of healthy and scoured bridge cases. The damage indicator enables visual identification of the location of scoured piers considering a range of natural frequencies of the system.
      9Scopus© Citations 10
  • Publication
    A 3D computational fluid dynamics validation study for the Queensferry Crossing Bridge with bus models on the deck
    In this paper, 3D CFD models of a bridge section of the Queensferry Crossing Bridge including a bus and other secondary structures on the deck are developed in OpenFOAM using the k-ω-SST turbulence model to determine the aerodynamic coefficients. The aerodynamic performance of the bridge deck accounting for several angles of attack with the bus located in various traffic lanes is investigated. The models are then validated with wind tunnel test results and good agreement is found between the 3D CFD models and the wind tunnel tests. The importance of the validated models is that they can be used in the future to study what wind speed should be set as a limit to prevent high-sided vehicles from overturning on the Queensferry Crossing Bridge.
  • Publication
    Using statistical analysis of an acceleration-based bridge weigh-in-motion system for damage detection
    This paper develops a novel method of bridge damage detection using statistical analysis of data from an acceleration-based bridge weigh-in-motion (BWIM) system. Bridge dynamic analysis using a vehicle-bridge interaction model is carried out to obtain bridge accelerations, and the BWIM concept is applied to infer the vehicle axle weights. A large volume of traffic data tends to remain consistent (e.g., most frequent gross vehicle weight (GVW) of 3-axle trucks); therefore, the statistical properties of inferred vehicle weights are used to develop a bridge damage detection technique. Global change of bridge stiffness due to a change in the elastic modulus of concrete is used as a proxy of bridge damage. This approach has the advantage of overcoming the variability in acceleration signals due to the wide variety of source excitations/vehicles-data from a large number of different vehicles can be easily combined in the form of inferred vehicle weight. One year of experimental data from a short-span reinforced concrete bridge in Slovenia is used to assess the effectiveness of the new approach. Although the acceleration-based BWIM system is inaccurate for finding vehicle axle-weights, it is found to be effective in detecting damage using statistical analysis. It is shown through simulation as well as by experimental analysis that a significant change in the statistical properties of the inferred BWIM data results from changes in the bridge condition.
      62Scopus© Citations 22