Options
Keenahan, Jennifer
Preferred name
Keenahan, Jennifer
Official Name
Keenahan, Jennifer
Research Output
Now showing 1 - 10 of 34
- PublicationAligning Learning Outcomes to Improve Communication and Learning Skills in an Interdisciplinary Problem-Based Learning EnvironmentEngineers 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.
118 - PublicationPortable Bridge WIM Data Collection Strategy for Secondary Roads(2012-06)
; ; ; A common method of collecting traffic loading data across a large road network is to use a network of permanent pavement-based WIM systems. An alternative is to use one or more portable Bridge Weigh-In-Motion systems which are moved periodically between bridges on the network. To make optimum use of such a system, a suitable data collection strategy is needed to choose locations for the system. This paper describes a number of possible strategies which the authors have investigated for the National Roads Authority in Ireland. The different strategies are examined and their advantages and disadvantages compared. Their effectiveness at detecting a heavy loading event is also investigated and the preferred approach is identified.327 - PublicationThe analysis of short signal segments and its application to Drive-by bridge inspection‘Drive-By’ damage detection is the concept of using sensors on a passing vehicle to detect damage in a bridge. At highway speeds, the vehicle spends a short amount of time on the bridge: it may not even go through a full oscillation, resulting in only a partial signal of the bridge motion being detected. Given that the spectral resolution of standard signal processing techniques depends on the length of data in the signal, they cannot be used to identify the bridge frequency accurately. In addition, the nonlinear and non-stationary nature of the vehicle-bridge interaction system poses challenges. An optimisation approach is proposed here as an alternative to standard signal processing techniques to overcome the challenges of short signals and the nonlinear nature of the drive-by system. Signal pollution due to the road profile is overcome using time-shifted bridge curvatures, a novel damage indicator.
74 - PublicationA Numerical Study of the Effect of Wind Barriers on Traffic and the Bridge Deck(Civil Engineering Research Association of Ireland, 2020-08-28)
; ; Wind actions can have a great impact on both bridges and traffic on bridges. However, structures designed to shelter the traffic from wind can influence the aerodynamic performance of the bridge deck, especially for long-span bridges. This study compares the effect of non-perforated walls and perforated walls used as wind barriers for traffic by conducting Computational Fluid Dynamics (CFD) simulations on three-dimensional geometries of a four-lane bridge deck. Steady-state simulations employ the Reynolds-Averaged Navier Stokes (RANS) method with the k-epsilon turbulence model and all simulations use parallel computing. An open-sourced software OpenFOAM is used.116 - PublicationUsing Instrumented Quarter-Cars for 'Drive By' Bridge InspectionThis paper investigates the concept of ‘drive by’ bridge inspection, a low cost alternative to Structural Health Monitoring (SHM), involving no sensors on the bridge. The concept may be of particular value after an extreme event, such as an earthquake or a flood, where a rapid indication of bridge condition is needed. Vehicle/bridge dynamic interaction is modelled to test the effectiveness of the approach. Damage is simulated here as a change in the bridge damping ratio. Two quarter cars are simulated crossing the bridge with accelerometers on board. A frequency domain analysis then illustrates changes in the Power Spectral Density of the accelerations as the bridge becomes damaged. The time-lagged difference in the accelerations is found to be effective in detecting damage. Results are compared to those with sensors on the bridge and found to be similar.
277 - Publication'Outside their Comfort Zone': Diverse and Engaging Approaches for Students Learning through a Different DisciplineI am an engineer and typically engineering students are assessed using calculation-based exams and written laboratory reports. However, I teach a 5-credit third year module which typically contains 60 architecture students and is compulsory. Simultaneously, these students complete a 20-credit module in studio design involving approximately 30 contact hours per week. The purpose of this module is to provide architecture students with the necessary training in engineering to fulfil requirements at both a professional and accreditation level. Whereas calculation-based exams are commonplace in the assessment of engineering students, using them to assess architecture students does not promote effective learning. It was not uncommon for architecture students to fail the engineering-style exam which suited those with a strong background in maths and physics. They seemed relatively unfamiliar with exams as a form of assessment as most of their submissions are studio portfolios. Exams tend to focus student attention on ‘reproductive thinking’ (Boud and Dochy, 2010). Students often end up cramming last minute, engaging in surface learning rather than the deep learning associated with ‘slow scholarship’ when assessment tasks require substantial involvement over time (Gibbs and Simpson, 2005). An alternative, more inclusive assessment approach was required for this module to improve engagement, to allow equal opportunity to demonstrate learning, to cater for the diversity of students and to reduce the need for individual adaptations for specific students.
60 - PublicationUsing instrumented vehicles to detect damage in bridges(Faculty of Engineering, University of Porto, 2012-07-22)
; ; ; Bridge structures are subject to continuous degradation due to the environment, ageing and excess loading. Monitoring of bridges is a key part of any maintenance strategy as it can give early warning if a bridge is becoming unsafe. This paper will theoretically assess the ability of a vehicle fitted with accelerometers on its axles to detect changes in damping of bridges, which may be the result of damage. Two vehicle models are used in this investigation. The first is a two degree-of-freedom quarter-car and the second is a four degree-of-freedom halfcar. The bridge is modelled as a simply supported beam and the interaction between the vehicle and the bridge is a coupled dynamic interaction algorithm. Both smooth and rough road profiles are used in the simulation and results indicate that changes in bridge damping can be detected by the vehicle models for a range of vehicle velocities and bridge spans.701 - PublicationIndirect Monitoring of Railway Bridges by Direct IntegrationRailway bridges are of importance as critical elements in transportation networks. Unfortunately, many railway bridges are old and these structures are subject to degradation over time. To monitor bridge structures, many methods are introduced. In recent years, indirect bridge monitoring methods have become more popular. These methods use passing vehicles to measure dynamic responses such as accelerations. In this paper, a new direct integration approach is introduced to directly calculate the apparent railway track profile (AP) that is consistent with the measured accelerations. An adaptation of the Newmark Beta numerical method is used for this purpose. Using AP, bridge displacement profile difference (BDPD) is calculated to monitor bridges. The BDPD is the difference between the baseline (healthy) profile and the apparent profile after damage and environmental effects. BDPD is sensitive to temperature change and bridge damage. It has its own frequency which is close to the bridge frequency.
133 - PublicationDynamic Load AllowanceChapter 4 provides a good explanation of the current state-of-the-art for the influence of dynamics on bridge traffic loading. It starts with an explanation of the concepts and a review of the various definitions used in the field, such as Dynamic Amplification factor and Impact Factor. It looks at how some of the main codes of practice in the world treat dynamics. A considerable portion of the chapter deals with the statistics of dynamic amplification. It is noted that the biggest dynamic amplifications tend to occur for light vehicle loading events. A statistical approach addresses this issue and provides a more appropriate allowance for dynamics which is called Assessment Dynamic Ratio. The influence of road surface roughness is considered and the implications of a local irregularity or pothole, as sometimes happens near the end joints. A number of field measurement campaigns of dynamic amplification are reported from various countries. These largely support the findings of the numerical studies.
53 - PublicationWind Forces on Medium-Span Bridges: A Comparison of Eurocode 1 Part 4 and Computational Fluid DynamicsBridges often have complicated geometries in complex terrain where they can be exposed to high wind loading. Current practice in designing for wind can be conservative. The drive for more lean construction motivates the study of computational modelling as an alternative to traditional methods of determining these wind loads. This paper compares wind forces determined using Eurocode 1 Part 4 with those determined by CFD modelling for a given bridge geometry, taking variations in altitude, location, wind speed and wind direction into account. Results indicate that the exposure factors used in Eurocode 1 Part 4 inflate the net wind force values. It was also found that the directional factor is conservative for wind forces on bridge decks but ineffective for wind forces on bridge piers in the x-direction. Furthermore, the Reynolds-Averaged Navier–Stokes equations (CFD) appear to produce smaller values of net wind force than Bernoulli’s equation (Eurocode). Bernoulli’s equation can only be applied to an ideal fluid, and Reynolds-Averaged Navier–Stokes equations can be applied to any viscous fluid—a further concern with the current practice.
11