Civil Structural & Environ Eng (Scholarly Publications)Civil Structural & Environ Eng (Scholarly Publications)http://hdl.handle.net/2262/2042014-11-28T16:58:58Z2014-11-28T16:58:58ZNonlinear Damage Identification in Fiber-reinforced Cracked Composite Beams through Time-space Wavelet AnalysisBASU, BISWAJITBRODERICK, BRIAN MICHAELhttp://hdl.handle.net/2262/721382014-11-25T03:03:44Z2014-01-01T00:00:00ZNonlinear Damage Identification in Fiber-reinforced Cracked Composite Beams through Time-space Wavelet Analysis
BASU, BISWAJIT; BRODERICK, BRIAN MICHAEL
It is well-known that wavelet analysis is, in the space domain, an efficient way to determinate the damage location (Pakrashi et al., 2007; Loutridis et al., 2004), while, in the time domain, it is an efficient tool to identify the system stiffness variation (Hou et al., 2000; Basu et al., 2008). Based on the idea of combining the information of the structural response in both space and time domains, a new time-space wavelet-based technique aimed at identifying the nonlinear behaviour of damage for SHM is presented. A FE model of a fiber-reinforced cantilever beam with a bridged crack is used to simulate the nonlinear static structural response. On the basis of particular conditions related to the Continuous Wavelet Transform (CWT) of the beam deflection and of the features of the 4th order Coiflets wavelet, a linear relation between the values of the relative rotation due to the crack and the normalized wavelet coefficients at the crack position is ruled out. By analysing through CWT the time sequence of the beam response in the space domain through the aforementioned linear relation, the nonlinear structural behaviour due to damage is identified. The effectiveness of the method in calibrating a small crack, is discussed with respect to the wavelet scale and the noise level.
PUBLISHED
2014-01-01T00:00:00ZShort-Term Forecasting of Bicycle Traffic Using Structural Time Series ModelsCAULFIELD, BRIANGHOSH, BIDISHAhttp://hdl.handle.net/2262/717542014-11-06T03:03:02Z2014-01-01T00:00:00ZShort-Term Forecasting of Bicycle Traffic Using Structural Time Series Models
CAULFIELD, BRIAN; GHOSH, BIDISHA
Short term forecasting algorithms are widely
used for prediction of vehicular traffic
flows
for adaptive traffic
management. However, despite the increasing interest in the
promotion of cycling in cities, little research has been carried
out into the use of traffic forecasting algorithms for bicycle
traffic. Structural time series models allow the various
components of a time series such as level, seasonal and
regression
effects
to be modelled separately to allow analysis of
previous trends and forecasting.
In this paper, a case study at
a
segregated bicycle lane in Dublin,
Ireland
was performed to
test the forecasting accuracy of structural time series models
applied to continuous
observations of
cyclist
traffic volumes. It
has been shown that the proposed
models can produce accurate
peak period
forecasts of
cyclist
traffic
volumes
at
both 1 hour
and
fifteen
minute resolution
and that the
percentage
errors
are lower for hourly forecasts.
The inclusion of weather metrics
as explanatory variables had varying effects on the forecasting
accuracies of the models.
These results directly aid the design of
traffic signal control systems accommodating cyclists.
2014-01-01T00:00:00ZQuantification of submarine/intertidal groundwater discharge and nutrient loading from a lowland karst catchment.GILL, LAURENCE WILLIAMhttp://hdl.handle.net/2262/717492014-11-04T03:03:02Z2014-01-01T00:00:00ZQuantification of submarine/intertidal groundwater discharge and nutrient loading from a lowland karst catchment.
GILL, LAURENCE WILLIAM
Summary Submarine groundwater discharge (SGD) is now recognised to be a process of significant importance to coastal systems and is of increasing interest within oceanographic and hydrologic research communities. However, due to the inherent difficulty of measuring SGD accurately, its quantification at any particular location is a relatively slow process often involving multiple labour intensive methods. In this paper, the SGD occurring at Kinvara Bay, the outlet of a lowland karst catchment in Western Ireland, is estimated using a hydrological model of the karst aquifer and then further verified by means of a relatively simple salinity survey. Discharge at Kinvara predominantly occurs via two springs, Kinvara West (KW) which serves as the outlet of a major, primarily allogenically fed, karst conduit network and Kinvara East (KE) which discharges water from more diffuse/autogenic sources. Discharge from these springs occurs intertidally and as such, their flow rates cannot be measured using traditional methods. Using the hydrological model, flow rates from KW were seen to vary between 5 – 15 m3/s with a mean value of 7.6 m3/s. Through hydrochemical analysis, this estimated discharge was found to be supplemented by an additional 14-18% via sources not accounted for by the model. Mean discharge at KE was also estimated as approximately 1.1 m3/s, thus the total mean discharge from both Kinvara Springs was determined to be 9.75-10 m3/s. Overall, the range of discharge was found to be lower than previous studies have estimated (as these studies had no means of quantifying attenuation within the conduit network). Combining this discharge with nutrient concentrations from the springs, the nutrient loading from the springs into the bay was estimated as 964 kg/day N and 19.8 kg/day P. This research illustrates the benefits of a numerical modelling approach to the quantification of SGD when used in the appropriate hydrological scenario.
PUBLISHED
2014-01-01T00:00:00ZAnalysing the usage of a segregated interurban cycleway (Greenway) in IrelandCAULFIELD, BRIANhttp://hdl.handle.net/2262/717062014-10-30T03:02:24Z2012-01-01T00:00:00ZAnalysing the usage of a segregated interurban cycleway (Greenway) in Ireland
CAULFIELD, BRIAN
This paper analyses the usage of a pilot greenway in a rural environment in Ireland.
The path is 42 km long and has several settlements and schools located along the
route. A survey was conducted in five schools along the route, to determine the usage
of the greenway by students and staff in the schools. This enabled observations to be
made in relation to the usage of the greenway. Usage of the path is established by
means of
counters located along the route. Average hourly day profiles of usage along
the path were created for different scenarios. This allowed the differences in usage to
be examined. The impact of national and public holidays was also observed. Usage
patterns
are also analysed in relation to a number of weather variables. The
relationships are determined by means of regression analysis. The cost of construction
of the path is known and therefore by establishing the user numbers the cost per trip
can be calculated. The average spend of a tourist
in Ireland
is known, and the quantity
of tourists
needed to pay for the path is estimated.
The analysis in this paper determined that there is a strong increase in the
cycling and walking rate in the areas immediately
surrounding the Greenway in
persons accessing places of education. The paper also determined that usage is higher
when there is a combination of the following variables; temperature is above
13.15 C
and sunshine hours are between 9.4 and 2.3 hours
2012-01-01T00:00:00Z