scholarly journals Experimental Investigation on the Anticollision Performance of Corrugated Steel-Reinforced Composites for Bridge Piers

2021 ◽  
Vol 2021 ◽  
pp. 1-17 ◽  
Author(s):  
Guicheng Chen ◽  
Haidong Huang ◽  
Zhongfu Xiang
Keyword(s):  
Energy Dissipation ◽  
Natural Frequency ◽  
Lateral Displacement ◽  
Plate Thickness ◽  
Steel Plates ◽  
Extreme Value Analysis ◽  
Value Analysis ◽  
Dissipation Effect ◽  
The Impact ◽  
Peak Value

To reduce the loss of life and property caused by the collision of a ship against a bridge pier, this study proposes a new type of anticollision facility. The facility uses corrugated steel plates and corrugated steel pipes (CSPs), or ordinary steel plates and corrugated steel pipes (OSPs), as structural elements to form a honeycomb structure, which can greatly improve the impact resistance of bridge piers and reduce any damage to ships. To evaluate the anticollision performance of the proposed anticollision facility, this work uses the CSPs and OSPs as study objects in the impact test research. A pendulum impact test system was utilized to compare and analyze the column with CSP and OSP specimens and the column without any anticollision facilities. Test results show that the CSP and OSP specimens have a relatively high energy dissipation effect. When the impact energy is small, the energy dissipation effect of the OSPs with the same plate thickness is stronger than that of the CSPs. When the impact energy is large, the energy dissipation effect of the CSPs with the same plate thickness is stronger than that of the OSPs. In addition, the extreme value analysis method is used to analyze the relationship curve between the peak value of the D1 lateral displacement and the specimen’s plate thickness, weight, and natural frequency; the optimal thickness, weight, and natural frequency values of the CSP and OSP specimens are also deduced. Taking the optimal value of the specimen’s natural frequency as a target, the structure of the CSP and OSP specimens is optimized. When the optimized plate thickness is 2.50 mm, the ratios of the optimal value of the specimen plate thickness, weight, and natural frequency to the optimal calculation value are all in the range of [0.80, 1.12]. OSP and CSP specimens are found to have the best energy dissipation effect. The peak value of the D1 lateral displacement of the top of the column equipped with the CSPs is at least 88.37% lower than that of the column without any anticollision facilities. For the top of the column equipped with the OSPs, the peak value of the D1 lateral displacement is at least 80.37% lower than that of the column without any anticollision facilities. Optimization results show that the extreme value analysis method is suitable for the optimal design of anticollision facilities for piers.

scholarly journals Determining Extreme Still Water Levels for Design and Planning Purposes Incorporating Sea Level Rise: Sydney, Australia

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 95
Author(s):  
Phil J. Watson
Keyword(s):  
Sea Level Rise ◽  
Water Level ◽  
Sea Level ◽  
Tide Gauge ◽  
Water Levels ◽  
Extreme Value Analysis ◽  
Tide Gauge Record ◽  
Value Analysis ◽  
Mean Sea Level ◽  
The Impact

This paper provides an Extreme Value Analysis (EVA) of the hourly water level record at Fort Denison dating back to 1915 to understand the statistical likelihood of the combination of high predicted tides and the more dynamic influences that can drive ocean water levels higher at the coast. The analysis is based on the Peaks-Over-Threshold (POT) method using a fitted Generalised Pareto Distribution (GPD) function to estimate extreme hourly heights above mean sea level. The analysis highlights the impact of the 1974 East Coast Low event and rarity of the associated measured water level above mean sea level at Sydney, with an estimated return period exceeding 1000 years. Extreme hourly predictions are integrated with future projections of sea level rise to provide estimates of relevant still water levels at 2050, 2070 and 2100 for a range of return periods (1 to 1000 years) for use in coastal zone management, design, and sea level rise adaptation planning along the NSW coastline. The analytical procedures described provide a step-by-step guide for practitioners on how to develop similar baseline information from any long tide gauge record and the associated limitations and key sensitivities that must be understood and appreciated in applying EVA.

Squall Detection and Analysis From Historical Satellite Data

2019 ◽  
Author(s):  
L. Renac ◽  
D. P. Hurdle ◽  
F. J. M. Enet ◽  
J. De Vroom
Keyword(s):  
Satellite Data ◽  
Measurement Data ◽  
Extreme Value Analysis ◽  
Intermediate Water ◽  
Design Data ◽  
Value Analysis ◽  
Design Values ◽  
The Impact ◽  
Long Term Measurement

Abstract Thunderstorms and squalls (fronts of contiguous thunderstorms) are associated with short but intense local winds that have a great impact on operability or design conditions for moored ship operations in the coastal zone. The brevity and local scale of such events makes them difficult to capture using standard measurement data and usually requires dedicated long-term measurement campaigns. Because the standard measurements available are usually based on 10-minute averages taken once an hour, such data is often not available. In the absence of conventional measured data, the use of satellite data can provide useful design data if analyzed and applied with caution. We present two case studies (West Africa and Brazil) where squalls have been identified in satellite data and used for extreme value analysis (EVA) to support the design of intermediate water depth mooring systems. The detection of squalls is confirmed with satellite imagery and the handling of this data for the EVA is presented in detail with assumptions made and the sensitivity of the results to these assumptions. The impact on design values is also discussed for both geographic locations.

Cyclic Performance of a Lightweight Rapidly Constructible and Reconfigurable Modular Steel Floor Diaphragm

2018 ◽  
Vol 763 ◽  
pp. 541-548 ◽  
Author(s):  
Eugene Boadi-Danquah ◽  
Duncan MacLachlan ◽  
Matthew Fadden
Keyword(s):  
Energy Dissipation ◽  
Seismic Design ◽  
Seismic Behavior ◽  
Plate Thickness ◽  
Steel Plates ◽  
Hysteretic Behavior ◽  
Inelastic Behavior ◽  
Cyclic Performance ◽  
Environmentally Sustainable ◽  
Energy Dissipation Capacity

One approach to making modern structures more economically and environmentally sustainable is designing and constructing them to be adaptable to rapidly changing markets and building occupancies. At the same time, these structures are required to be resilient to seismic events. As a step towards meeting these goals, a lightweight, two-way, rapidly constructible and reconfigurable modular steel floor (RCRMSF) system has been developed. The system is fabricated from light-gauge steel plates sandwiching a grillage of orthogonally arranged cold formed Z-purlins, can span 9.1 m x 12.2 m, requires only girder supports, and fits within current steel construction framework. This study investigates the seismic behavior of the RCRMSF diaphragm through the use of high fidelity nonlinear finite element (FE) models. Six full-scale cantilever diaphragm models have been developed to study the effect of varying RCRMSF configurations and end support details. Both monotonic and cyclic loading protocols are used to determine the stiffness, strength, energy dissipation capacity, and general hysteretic behavior of the diaphragms. Based on the FE models, the behavior of the RCRMSF diaphragm is influenced primarily by the plate thickness and perimeter connection detail to the supporting steel frame. Overall, the RCRMSF has adequate diaphragm stiffness and strength, and shows favorable energy dissipation capacity due to its post-peak inelastic behavior. This observation implies that the RCRMSF can serve as an alternative solution to current seismic design and construction practices.

Parametric Study of Hysteretic Behaviour of Combined Welded Heavy Steel Plates with Accumulative Damage

2011 ◽  
Vol 194-196 ◽  
pp. 1887-1891
Author(s):  
Na Yang ◽  
Jing Jing Zhang ◽  
Ting Guo
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Plastic Strain ◽  
Steel Plate ◽  
Plate Thickness ◽  
Damage Model ◽  
Thickness Ratio ◽  
Steel Plates ◽  
Hysteretic Behavior ◽  
Previous Researcher

The accumulative damage model in which the material’s plastic strain is defined as variable and the energy dissipation is also considered is applied to the combined welded heavy steel plates. And the reliability of the model is confirmed by comparing the computed results in finite element project ABAQUS to tested results from previous researcher. On that basis, a series of steel plate components are computed to analyze their hysteretic curves and ductility factors. The influences of steel plate thickness, web’s height-thickness ratio and flange’s width-thickness ratio on hysteretic behavior are studied.

scholarly journals Numerical Modal Analyses of Beam-Supported Plates with Varying Thicknesses

2021 ◽  
Vol 26 (3) ◽  
pp. 259-267
Author(s):  
Adil Yucel
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Plate Thickness ◽  
Steel Plates ◽  
Mode Shapes ◽  
General Surface

In this study, numerical modal analyses are conducted on steel plates supported with various numbers of transverse beams. Natural frequency and mode shapes are obtained for each model. The same analyses are also repeated for plates with various thicknesses. Finally, the correlation between the number of supporting beams and natural frequencies is examined. The change in natural frequencies with respect to plate thickness is emphasized. In addition, general surface regression formulas of flexural natural frequencies with respect to the number of supporting beams and plate thicknesses are obtained.

scholarly journals Combining Groundwater Flow Modeling and Local Estimates of Extreme Groundwater Levels to Predict the Groundwater Surface with a Return Period of 100 Years

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 373
Author(s):  
Hans Kupfersberger ◽  
Gerhard Rock ◽  
Johannes C. Draxler
Keyword(s):  
Groundwater Flow ◽  
Return Period ◽  
Groundwater Level ◽  
Flow Model ◽  
Extreme Value Analysis ◽  
Environmental Damage ◽  
Groundwater Flow Model ◽  
Value Analysis ◽  
Groundwater Levels ◽  
The Impact

Knowledge about extreme groundwater levels is needed to avoid structural or environmental damage by groundwater flooding. Typically, distributions of extreme groundwater levels are generated by interpolation between results derived from local extreme value analysis at groundwater observation wells. As an alternative methodology, we propose to apply the Gumbel distribution to groundwater level time series, which are computed by a groundwater flow model. In the approach, model-based and observation-based extreme groundwater values are compared at every observation well using the model simulation period and the longest available observation period to calculate correction values that are regionalized over the model area. We demonstrate the applicability of the approach at the Südliches Wiener Becken (SWB) aquifer south of Vienna, where a groundwater flow model between 1993 to 2017 is available to compute the distribution of the groundwater levels with a hundred year return period (GLsWHYRP). We could show that the resulting GLsWHYRP are generally increased in regions of groundwater recharge and decreased in regions of groundwater discharge. The developed approach can also be used to assess the impact of changing boundary conditions on groundwater level and extreme highs and lows based on corresponding model scenarios.

Plotting positions for fitting distributions and extreme value analysis

2013 ◽  
Vol 40 (2) ◽  
pp. 130-139 ◽  
Author(s):  
M. Fuglem ◽  
G. Parr ◽  
I.J. Jordaan
Keyword(s):  
Probability Distributions ◽  
Extreme Value ◽  
Extreme Value Analysis ◽  
Random Data ◽  
Value Analysis ◽  
Correct Method ◽  
Simulation Techniques ◽  
Probability Paper ◽  
Distribution Parameters ◽  
The Impact

Random data are often examined on plotting paper to determine appropriate probability distributions and distribution parameters for extreme-value analyses and other applications. Engineers are not always aware of criteria that have been developed and published for selecting the type of probability paper, nor of the impact that the selection can have on results. Some of the advice available in the literature is inaccurate, so it is important that the basis for using the correct method be clearly demonstrated. In the present paper, it is confirmed using straightforward simulation techniques that use of plotting position methods specific to the distribution being considered is appropriate and that use of other plotting position methods can give inaccurate results.

Critical Plate Thickness for Energy Dissipation During Sphere–Plate Elastoplastic Impact Involving Flexural Vibrations

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Deepak Patil ◽  
C. Fred Higgs
Keyword(s):  
Energy Dissipation ◽  
Thin Plate ◽  
Material Properties ◽  
Input Parameter ◽  
Plate Thickness ◽  
Practical Importance ◽  
Sphere Diameter ◽  
Impact Parameters ◽  
Flexural Vibrations ◽  
The Impact

Solid processing storage and conveying units (e.g., hoppers, silos, tumblers, etc.) often involve the collision of granular media with relatively thin walls. Therefore, the impact of a sphere with a thin plate is a problem with both fundamental and practical importance. In the present work, the normal elastoplastic impact between a sphere and a thin plate is analyzed using an explicit finite element method (FEM). The impact involves plastic deformation and flexural vibrations, which when combined results in significant energy dissipation. One way to quantify the energy dissipation is to employ the coefficient of restitution (COR), which is also a key input parameter needed in various granular flow models. The results were validated against the available experimental data. It is observed that, in addition to material properties and impact parameters, the energy dissipation is strongly dependent on the ratio of plate thickness to sphere diameter. A comprehensive parametric study is conducted to evaluate the effect of material properties, geometry, and impact parameters on the energy dissipation. For the impact velocities commonly observed in granular systems (V = 5 m/s or less), it was determined that the energy lost to flexural vibrations can be neglected if the plate thickness is more than twice the sphere diameter, i.e., tcr > 2d. In this scenario, the mode of energy dissipated is primarily due to the plasticity effects.

scholarly journals Changes in runoff time series in Thuringia, Germany – Mann-Kendall trend test and extreme value analysis

2012 ◽  
Vol 31 ◽  
pp. 49-56 ◽  
Author(s):  
J. Danneberg
Keyword(s):  
Time Series ◽  
Time Frame ◽  
Extreme Value Analysis ◽  
Trend Test ◽  
Mean Flow ◽  
Value Analysis ◽  
Time Period ◽  
Flood Quantiles ◽  
Winter Time ◽  
The Impact

Abstract. Qualified knowledge about the impacts of climate change on hydrology is needed for the derivation of adaptation measures in the water sector. As temperature and precipitation time series in Thuringia, Germany of the last 50 years reveal that the climate is becoming warmer and drier in summer and wetter in winter, the question of changes in runoff time series arises. In the presented study, simple robust analysis approaches to detect changes in runoff characteristics are applied. A selection of 19 anthropogenically undisturbed Thuringian catchments with daily runoff time series of up to 78 years without gaps, covering different landscapes and climatic conditions in Thuringia, is made. Indicators of mean, high, and low runoff in the hydrological year, winter and summer are derived and tested for trends, using the non-parametric Mann-Kendall trend test. To analyze the impact of significant lag-1 autocorrelation (AR) in the series, a prior removal of AR from the series before testing for trend (trend-free-pre-whitening) is performed. Results show that removal of AR has only minor influence on test results and is therefore considered as not necessary. Mean flow and high flow indicators in annual and winter time frame show increasing trends, escpecially in catchments in the higher regions of Thuringia like the Thuringian forest. In summer, all indicators show decreasing trends, especially in the drier central and northern Thuringian basin area. In order to assess changes in floods, 8 gauges, covering the 50-year time period 1949–1999, are selected. Annual maximum flow series are derived for the hydrological year, winter and summer. After fitting of 8 theoretical distributions to the samples by the method of L-moments, 3 goodness-of-fit tests are applied. Flood quantiles for the return periods 2, 5, 10, 20, 50 and 100 years are calculated from means of well fitted distributions for all gauges. To analyze change in flood values, the relative difference of flood quantiles in 2 time periods, 1949–1979 (TP 1) and 1969–1999 (TP 2), with respect to the whole time period 1949–1999 are calculated. Results show that flood values have increased in the later time period in annual and winter time frame and have decreased in summer.

Modeling European hot spells using extreme value analysis

2014 ◽  
Vol 58 (3) ◽  
pp. 193-207 ◽  
Author(s):  
C Photiadou ◽  
MR Jones ◽  
D Keellings ◽  
CF Dewes
Keyword(s):  
Extreme Value ◽  
Extreme Value Analysis ◽  
Value Analysis ◽  
Hot Spells
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