scholarly journals Numerical Analysis of Compressed Masonry Columns

2020 ◽  
Author(s):  
Aneta Libecajtová
Keyword(s):  
Ultimate Load ◽  
Compressive Load ◽  
Heterogeneous Model ◽  
Before And After ◽  
Frp Reinforcement ◽  
Commercial Software Package ◽  
Independent Behavior ◽  
Frp Strips ◽  
Frp Wrapping ◽  
Good Agreement

This paper presents a three-demensional micro-model for an unreinforced masonry (URM) column and masonry columns reinforced by FRP wrapping (RM). The column with dimensions of 0.3 x 0.3 x 1 m was constituted by twelve rows of solid burnt bricks bonded by mortar joints. The RM column was wrapped in four external FRP sheets. A heterogeneous model, in which masonry units, mortar joints and reinforcement are materially and geometrically accurately described, was chosen. Both bricks and mortar are modelled with independent behavior in compression and tension. The FRP reinforcement is assumed to behave linear-elastically. The reinforcement was modelled under the assumption of perfect adhesion between the elastic FRP strips and the damageable masonry support. Numerical results are compared with experimental ones in order to confirm conclusions about the behavior of URM and RM columns under concentric compressive load determined based on the experimental part of the research program. The comparison between experimental and numerical findings shows good agreement and the adopted numerical model is suitable to predict the ultimate load and allows a better understanding of the behavior of brick masonry columns under concentric compression before and after reaching the ultimate load. For all simulations, the commercial software package ABAQUS was used.

scholarly journals Numerical studies on residual strength of dented tension leg platforms under compressive load

2020 ◽  
Vol 14 (3) ◽  
pp. 96-109
Author(s):  
Quang Thang Do ◽  
Van Nhu Huynh ◽  
Dinh Tu Tran
Keyword(s):  
Axial Compression ◽  
Residual Strength ◽  
Compressive Load ◽  
Element Model ◽  
Test Results ◽  
Offshore Structure ◽  
Numerical Studies ◽  
Commercial Software Package ◽  
Dent Depth ◽  
Good Agreement

This paper focuses on numerical investigations and derived formulation to evaluate the residual strength of tension leg platforms (TLPs) with the local denting damage under axial compression loading. The damage generation scenarios in this research are represented the collision accidents of offshore stiffened cylinders TLPs with supply ships or floating subjects. The finite element model is performed using a commercial software package ABAQUS, which has been validated against the experiments from the authors and other researchers. Case studies are then performed on design examples of LTPs when considering both intact and damaged conditions. Based on the rigorous numerical results, the new simple design formulations to predict residual strength of dented TLPs are derived through a regression study as the function of a non-dimensional dent depth. The accuracy and reliability of the derived formulation are validated by comparing it with the available test results in the literature. A good agreement with existing test data for ship-offshore structure collisions is achieved. Keywords: dented stringer-stiffened cylinder; residual strength; tension leg platforms (LTPs); axial compression; residual strength formulation.

scholarly journals Impedance Spectroscopy of Lead-Free Ferroelectric Coatings

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 221
Author(s):  
Mariya Aleksandrova ◽  
Ivailo Pandiev
Keyword(s):  
Composite Coatings ◽  
Electrical Circuit ◽  
Ferroelectric Materials ◽  
Piezoelectric Transducers ◽  
Lead Free ◽  
Electrical Behavior ◽  
Oxide Composite ◽  
Before And After ◽  
Frequency Dependences ◽  
Good Agreement

This paper presents impedance measurements of ferroelectric structures involving lead-free oxide and polymer-oxide composite coatings for sensing and energy harvesting applications. Three different ferroelectric materials grown by conventional microfabrication technologies on solid or flexible substrates are investigated for their basic resonant characteristics. Equivalent electrical circuit models are applied to all cases to explain the electrical behavior of the structures, according to the materials type and thickness. The analytical results show good agreement with the experiments carried out on a basic types of excited thin-film piezoelectric transducers. Additionally, temperature and frequency dependences of the dielectric permittivity and losses are measured for the polymer-oxide composite device in relation with the surface morphology before and after introduction of the polymer to the functional film.

scholarly journals Measurements of urban traffic parameters before and after road reconstruction

2021 ◽  
Vol 11 (1) ◽  
pp. 365-376
Author(s):  
Andrzej Bąkowski ◽  
Leszek Radziszewski
Keyword(s):  
Urban Traffic ◽  
Noise Model ◽  
Vehicle Traffic ◽  
The Road ◽  
Passenger Vehicles ◽  
Before And After ◽  
Traffic Volumes ◽  
National Road ◽  
The City ◽  
Good Agreement

Abstract The study analyzed the parameters of vehicle traffic and noise on the national road in the section in the city from 2011 to 2016. In 2013–2014 this road was reconstructed. It was found that in most cases, the distribution of the tested variable was not normal. The median and selected percentiles of vehicle traffic parameters and noise were examined. The variability and type A uncertainty of the results were described and evaluated. The results obtained for the data recorded on working and non-working days were compared. The vehicle cumulative speed distributions, for two-way four-lane road segments in both directions were analyzed. A mathematical model of normalized traffic flow has been proposed. Fit factor R2 of the proposed equations to the experimental data for passenger vehicles ranges from 0.93 to 0.99. It has been shown that two years after the road reconstruction, the median noise level did not increase even though traffic volumes and vehicle speeds increased. The Cnossos noise model was validated for data recorded over a period of 6 years. A very good agreement of the medians determined according to the Cnossos-EU model and the measured ones was obtained. It should be noted, however, that for the other analyzed percentiles, e.g. 95%, the discrepancies are larger.

Numerical Simulation of Compressive Residual Strength for Damaged Composite Laminates

2012 ◽  
Vol 525-526 ◽  
pp. 385-388
Author(s):  
Tian Jiao Qu ◽  
Xi Tao Zheng ◽  
Di Zhang
Keyword(s):  
Composite Laminates ◽  
Impact Test ◽  
Compressive Load ◽  
Low Velocity Impact ◽  
Fiber Breakage ◽  
Low Velocity ◽  
Appearance Time ◽  
Finite Element Software ◽  
Set Up ◽  
Good Agreement

After the low-velocity impact test of composite laminates of T800/BA9916, CAI test and compression test of laminates with a hole have been carried out. Two types of models were set up by the finite element software ABAQUS respectively. The FEA results were good agreement with the testing results. The investigation of models with a hole indicates that the appearance time of ultimate compressive load is earlier than that of fiber breakage expanding to boundary. Moreover, the diameter and the depth of blind hole significantly influence the ultimate compressive load.

scholarly journals Discharge and Sediment Transport in a River Basin. Assessment Before and After the Construction of a Dam at the Upper Basin Boundary

2021 ◽  
Author(s):  
George Paschalidis ◽  
Ilias IIordanidis ◽  
Petros Anagnostopoulos
Keyword(s):  
Sediment Transport ◽  
Meteorological Data ◽  
Climatic Data ◽  
Northern Greece ◽  
Basin Boundary ◽  
Software Packages ◽  
Before And After ◽  
The Mean ◽  
Gis Interface ◽  
Good Agreement

Abstract The purpose of this study is the evaluation of runoff and sediment transport in the basin of the Nestos River (Northern Greece) downstream of the dam of Platanovrisi, constructed in 1998. The model used for the simulation was AGNPS, which is based on the Revised Universal Soil Loss Equation (RUSLE), combined with a GIS interface. Two different simulations were conducted, one for the years 1980-1990 and another for the period 2006-2030, before and after the construction of the dam respectively. For the simulation for the period 1980-1990 existing meteorological data were employed, and the results were in good agreement with those of a different study (Hrissanthou, 2002). The simulation for the period 2006-2030 was based on rainfall and climatic data generated from the software packages GlimClim and ClimGen. The mean runoff was by 5% lower and the mean annual sediment yield by 20% lower than the corresponding values for the period 1980-1990.

scholarly journals Use of Mini-CT Specimens for Fracture Toughness Characterization of Low Upper-Shelf Linde 80 Weld Before and After Irradiation

2018 ◽  
Author(s):  
Mikhail A. Sokolov
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Master Curve ◽  
Collaborative Program ◽  
Before And After ◽  
Minimum Number ◽  
Real Practice ◽  
Reactor Pressure ◽  
Good Agreement

Mini-CT specimens are becoming a highly popular geometry for use in reactor pressure vessel (RPV) community for direct measurement of fracture toughness in the transition region using the Master Curve methodology. In the present study, Mini-CT specimens were machined from previously tested Charpy specimens of the Midland low upper-shelf Linde 80 weld in both, unirradiated and irradiated conditions. The irradiated specimens have been characterized as part of a joint ORNL-EPRI-CRIEPI collaborative program. The Linde 80 weld was selected because it has been extensively characterized in the irradiated condition by conventional specimens, and because of the need to validate application of Mini-CT specimens for low upper-shelf materials — a more likely case for some irradiated materials of older generation RPVs. It is shown that the fracture toughness reference temperatures, To, derived from these Mini-CT specimens are in good agreement with To values previously recorded for this material in the unirradiated and irradiated conditions. However, this study indicates that in real practice it is highly advisable to use a much larger number of specimens than the minimum number prescribed in ASTM E1921.

Assessment and documentation of incontinence-associated dermatitis after implementation of a standardised instrument: a comparative study

2019 ◽  
Vol 28 (Sup9) ◽  
pp. S4-S11 ◽  
Author(s):  
Mary Montague ◽  
Matthew Karafa ◽  
Nancy M. Albert
Keyword(s):  
Standard Deviation ◽  
Weighted Kappa ◽  
Severity Index ◽  
Skin Condition ◽  
Assessment Instrument ◽  
Clinical Nurses ◽  
Before And After ◽  
Implementation Period ◽  
Improved Accuracy ◽  
Good Agreement

Objective: In this study, clinical nurses' documentation of incontinence-associated dermatitis (IAD) were compared with wound expert documentation before and after implementing a valid, reliable severity index (SI) instrument. Methods: A prospective, non-equivalent, two group comparative design within three hospital medical units. Pre- and post-implementation skin condition documentation were compared by clinician type, and post-implementation IADSI scores were assessed for agreement using standard and weighted Kappa. Results: Of 89 patients (pre-, n=48 and post-, n=38), mean (standard deviation) age was 72.4±13.7 years and 57.3% had IAD. Mean IADSI score was 13.2 (standard deviation: 10.5; range: 0–52), reflecting pink intact skin. Post-implementation, skin documentation between clinicians was more likely to match, from 35.4 to 84.2%, p<0.001. Post-implementation, after controlling for age, gender and race, the odds ration (OR) of matched documentation between clinicians was 5.80 ([95% confidence interval: 1.8, 18.6], p=0.003) compared with pre-implementation. In the post-implementation period, standard Kappas for agreement in clinical nurse-wound expert documentation in the lower back/buttocks/upper thigh areas ranged from 0.82 to 1.0, reflecting very good agreement. Weighted kappas ranged from 0.76 to 1.0, also reflecting good to very good agreement. Conclusion: Implementation of an IADSI assessment instrument improved accuracy of IAD documentation.

scholarly journals Multi-satellite sensor study on precipitation-induced emission pulses of NO<sub><i>x</i></sub> from soils in semi-arid ecosystems

2016 ◽  
Author(s):  
J. Zörner ◽  
M. J. M. Penning de Vries ◽  
S. Beirle ◽  
H. Sihler ◽  
P. R. Veres ◽  
...  
Keyword(s):  
Time Series ◽  
Arid Ecosystems ◽  
Vertical Column ◽  
Dry Spell ◽  
Before And After ◽  
Soil Emissions ◽  
Sahel Region ◽  
Individual Grid ◽  
Semi Arid ◽  
Good Agreement

Abstract. We present a top-down approach to infer and quantify rain-induced emission pulses of NOx (≡ NO + NO2), stemming from biotic emissions of NO from soils, globally with a spatial resolution of 0.25° from satellite-borne measurements of NO2. This is achieved by synchronizing time series at single grid pixels according to the first day of rain after a dry spell of prescribed duration. The full track of the temporal evolution several weeks before and after a rain pulse is retained with daily resolution. These are needed for a sophisticated background correction, which accounts for seasonal variations in the time series and allows for improved quantification of rain-induced soil emissions. We find strong peaks of enhanced NO2 Vertical Column Densities (VCDs) on the first day of rainfall after prolonged droughts in many semi-arid regions of the world, in particular in the Sahel. Detailed investigations show that the rain-induced NO2 pulse detected by the OMI, GOME-2 and SCIAMACHY satellite instruments could not be explained by other sources, such as biomass burning or lightning, or by retrieval artefacts (e.g. due to clouds). For the Sahel region, absolute enhancements of the NO2 VCDs on the first day of rain based on OMI measurements 2007–2010 are on average 4 × 1014 molec cm−2 and exceed 1 × 1015 molec cm−2 for individual grid cells. Assuming a NOx lifetime of 4 h, this corresponds to soil NOx emissions in the range of 6 ng N m−2 s−1 up to 65 ng N m−2 s−1, in good agreement with literature values. Apart from the clear first-day peak, NO2 VCDs show moderately enhanced NO2 VCDs of 2 × 1014 molec cm−2 compared to background over the following two weeks suggesting potential further emissions during that period of about 3.3 ng N m−2 s−1.

scholarly journals Comparison of Above-Water Seabird and TriOS Radiometers along an Atlantic Meridional Transect

2020 ◽  
Vol 12 (10) ◽  
pp. 1669
Author(s):  
Krista Alikas ◽  
Viktor Vabson ◽  
Ilmar Ansko ◽  
Gavin H. Tilstone ◽  
Giorgio Dall’Olmo ◽  
...  
Keyword(s):  
State Of The Art ◽  
Ocean Color ◽  
Percentage Difference ◽  
Wide Range ◽  
Before And After ◽  
Reference Measurements ◽  
Satellite Ocean Color ◽  
Good Agreement

The Fiducial Reference Measurements for Satellite Ocean Color (FRM4SOC) project has carried out a range of activities to evaluate and improve the state-of-the-art in ocean color radiometry. This paper described the results from a ship-based intercomparison conducted on the Atlantic Meridional Transect 27 from 23rd September to 5th November 2017. Two different radiometric systems, TriOS-Radiation Measurement Sensor with Enhanced Spectral resolution (RAMSES) and Seabird-Hyperspectral Surface Acquisition System (HyperSAS), were compared and operated side-by-side over a wide range of Atlantic provinces and environmental conditions. Both systems were calibrated for traceability to SI (Système international) units at the same optical laboratory under uniform conditions before and after the field campaign. The in situ results and their accompanying uncertainties were evaluated using the same data handling protocols. The field data revealed variability in the responsivity between TRiOS and Seabird sensors, which is dependent on the ambient environmental and illumination conditions. The straylight effects for individual sensors were mostly within ±3%. A near infra-red (NIR) similarity correction changed the water-leaving reflectance (ρw) and water-leaving radiance (Lw) spectra significantly, bringing also a convergence in outliers. For improving the estimates of in situ uncertainty, it is recommended that additional characterization of radiometers and environmental ancillary measurements are undertaken. In general, the comparison of radiometric systems showed agreement within the evaluated uncertainty limits. Consistency of in situ results with the available Sentinel-3A Ocean and Land Color Instrument (OLCI) data in the range from (400…560) nm was also satisfactory (−8% < Mean Percentage Difference (MPD) < 15%) and showed good agreement in terms of the shape of the spectra and absolute values.

Effects of Local Metal Loss on Deformability of Line Pipes Subjected to Compressive Load

2005 ◽  
Author(s):  
Yoshikazu Hashimoto ◽  
Hiroshi Yatabe ◽  
Naoto Hagiwara ◽  
Noritake Oguchi
Keyword(s):  
Analytical Method ◽  
Compressive Load ◽  
Fe Analysis ◽  
Ground Movement ◽  
Metal Loss ◽  
Line Pipe ◽  
Parametric Studies ◽  
Scale Experiment ◽  
The Relationship ◽  
Good Agreement

In this paper, the deformability of line pipe with local metal loss was examined. A full-scale experiment and a finite element (FE) analysis were carried out for line pipe with local metal loss subjected to an axial compressive load. As a result, a good agreement was obtained between the analytical and experimental results. This indicated that the present analytical method was applicable to evaluate the deformability of line pipes with local metal loss subjected to a large ground movement. Parametric studies were then conducted to clarify the relationship between the geometry of the local metal loss and the deformability using the FE analytical method.

Sign in / Sign up

Export Citation Format

Share Document