Cyclic Behavior of CLT Wall Systems: Experimental Tests and Analytical Prediction Models

2015 ◽  
Vol 141 (11) ◽  
pp. 04015034 ◽  
Author(s):  
Igor Gavric ◽  
Massimo Fragiacomo ◽  
Ario Ceccotti
Keyword(s):  
Prediction Models ◽  
Experimental Tests ◽  
Cyclic Behavior ◽  
Analytical Prediction

scholarly journals Impedance modelling of acoustically treated circumferential grooves for over-tip-rotor fan noise suppression

2020 ◽  
Vol 19 (6-8) ◽  
pp. 277-293
Author(s):  
Sergi Palleja-Cabre ◽  
Brian J Tester ◽  
R Jeremy Astley ◽  
Hadrien Beriot
Keyword(s):  
Noise Suppression ◽  
Prediction Models ◽  
Axial Direction ◽  
Analytical Prediction ◽  
Azimuthal Direction ◽  
Fan Noise ◽  
Turbofan Engines ◽  
Circumferential Groove ◽  
Equivalent Impedance ◽  
Grooved Surface

Experimental investigation of Over-Tip-Rotor circumferential groove liners has shown potential for fan noise suppression in turbofan engines whilst providing minimal penalty in fan aerodynamic performance. The validation of Over-Tip-Rotor liner analytical prediction models against published experimental data requires the modelling of an equivalent impedance for such acoustic treatments. This paper describes the formulation of two analytical groove impedance models as semi-locally reacting liners, that is locally reacting in the axial direction and non-locally reacting in the azimuthal direction. The models are cross-verified by comparison with high-order FEM simulations, and applied to a simplified Over-Tip-Rotor configuration consisting of multiple grooves excited by a monopole point source located close to the grooved surface.

scholarly journals Investigation of crack prediction in reinforced concrete liquid containing structures

2021 ◽  
Author(s):  
Armin Zyarishalmani
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Theoretical Calculations ◽  
Experimental Tests ◽  
Fiber Reinforced Polymers ◽  
Water Leakage ◽  
Positive Role ◽  
Reinforced Polymers ◽  
Cracking Behavior ◽  
Advantages And Disadvantages

Cracking in liquid containing structures, if it is not properly controlled, can have serious detrimental effects on the overall system functionality. Having a consistent knowledge of concrete cracking characteristics is essential for a designer to ensure serviceability requirements of the structure. In spite of several proposed crack prediction models that have been used as the base for design codes, still a lack of certainty can be clearly felt in predicting cracking behavior of reinforced concrete. This is due to the fact that cracking is a very complex phenomenon in which numerous factors are involved, and it is always too cumbersome to take the effects of all these influential aspects into account. In order to acquire more insight into this issue, a comprehensive attempt has been made both experimentally and theoretically here in this study. This research is primarily dealing with cracks that develop under monotonic increasing load which is the main cause for the formation of wide cracks among other causes such as shrinkage or temperature. In this regard, several laboratory tests were conducted on a one meter wide strip of a tank wall. These experiments covered a range of loading configuration that would enable various combinations of stresses across the reinforced concrete section. Cracking behavior and water tightness of the slab were closely monitored and reported. Fiber reinforced polymers were shown to be a suitable means of remediation in reducing water leakage or recovering structural strength. A positive role of concrete autogenous healing on water leakage was investigated during the practical test. A comparison is made between experimental results and several recent well-known crack prediction models, through which their advantages and disadvantages are revealed and discussed. Several finite element models (FEM) have been successfully built with the aid of computer program ABAQUS/6.5 to capture the post-failure stress/strain condition in concrete and reinforcement, the results of which are perfectly matching with those obtained from experimental tests and theoretical calculations.

scholarly journals NUMERICAL INVESTIGATION ON CYCLIC BEHAVIOR OF RING-BEAM CONNECTION TO GANGUE CONCRETE FILLED STEEL TUBULAR COLUMNS

2021 ◽  
Keyword(s):  
Cyclic Loading ◽  
Failure Modes ◽  
High Capacity ◽  
High Strength ◽  
Experimental Tests ◽  
Load Level ◽  
Cyclic Behavior ◽  
Tubular Columns ◽  
Earthquake Resistant ◽  
Parametric Studies

As a promising composite structure, gangue concrete filled steel tubular (GCFST) column exhibites favarable characteristics including high strength and economic efficiency. This paper conducted numerical investiagations on structural behavior of a ring-beam connection to GCFST column with concrete beam under cyclic loading. Furthermore, finite element models of column-beam connections were developed using ABAQUS and validated against full-scale experimental tests to identify accuracy of selected modeling approaches. Using these validated models, stress distribution of each component was examined to study the force-transferring mechanism among the components and failure modes of the ring-beam connection. Research study indicated that the ring-beam connection showed a reasonable force-transferring mechanism under cyclic loading and the remarkable earthquake-resistant performance with high capacity and acceptable ductility. Finally, parametric studies were performed to assess the influences of beam-to-column stiffness ratio,steel ratio, axial load level, and concrete compressive strength on connection cyclic behaviors. Parametric studies provided some suggestions and references for the application of the ring-beam connection in various engineering projects.

scholarly journals Analysis of draught discomfort prediction models

2021 ◽  
Vol 2069 (1) ◽  
pp. 012236
Author(s):  
S M Hooshmand ◽  
S A Zolfaghari ◽  
J Toftum
Keyword(s):  
Environmental Conditions ◽  
Indoor Environment ◽  
Prediction Models ◽  
Thermal Conditions ◽  
Experimental Tests ◽  
High Accuracy ◽  
Maximum Deviation ◽  
Experimental Conditions ◽  
The Common ◽  
The Mean

Abstract One of the common local thermal discomforts that happen in an indoor environment is draught. Because of the importance of draught, many studies have been carried out to develop equations to calculate the draught rate. But because these equations are obtained from experimental tests in narrow experimental windows, their accuracy under wider environmental conditions should be analyzed. In this paper, the accuracy of equations obtained from the literature were investigated. Each equation predicted the draught rate with high accuracy and mean error of 5.3, 6.8, and 2.2% under the thermal conditions in which the equation was obtained. When applying the equations to different thermal conditions, the mean and maximum errors significantly increased and showed errors in predicting the draught rate with a maximum deviation of 63.5, 51.6, and 49.7%. These equations in some cases, even could not predict the draught rate of the reported draught discomfort percentage. Based on the results, each equation had its limitations and none of the studied equations could accurately predict the draught rate in all experimental conditions. An index that considers all relevant parameters in predicting draught discomfort can lead to a better draught rate prediction.

scholarly journals COVID-19: Opportunity or threat for European tourism

TIMS Acta ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 93-101
Author(s):  
Patricia Ardeljan ◽  
Laura Cismaș ◽  
Vera Medić
Keyword(s):  
Prediction Models ◽  
Sustainable Tourism ◽  
Tourism Industry ◽  
International Tourism ◽  
Analytical Prediction ◽  
Global Pandemic ◽  
Tourism Sector

International and European tourism underwent a constant and almost unprecedented development in the last decades. In 2018, international tourism displayed the ninth year of consecutive growth that exceeded even the increase of world GDP according to UNWTO data. This ascending trend continued in 2019, and the perspectives were promising according to predictions. The beginning of 2020 brought with it the outspread of a global pandemic and one of the most sensitive industries proved to be the industry of tourism and travel. The pandemic is from this perspective an opportunity for reconsidering the criteria for ensuring sustainable tourism while it proved the frailty of the entire tourism sector. The paper presents a brief analysis of the developments in international tourism, especially regarding European tourism in the pre-pandemic context. It is based on the principles of sustainability that should govern this industry and perceive the opportunities or threats of this pandemic. Regarding the methodology, we used the main available data and discussed the current analytical prediction models, because COVID-19 has changed and will continue to change the tourism industry.

scholarly journals Investigation of crack prediction in reinforced concrete liquid containing structures

2021 ◽  
Author(s):  
Armin Zyarishalmani
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Theoretical Calculations ◽  
Experimental Tests ◽  
Fiber Reinforced Polymers ◽  
Water Leakage ◽  
Positive Role ◽  
Reinforced Polymers ◽  
Cracking Behavior ◽  
Advantages And Disadvantages

Cracking in liquid containing structures, if it is not properly controlled, can have serious detrimental effects on the overall system functionality. Having a consistent knowledge of concrete cracking characteristics is essential for a designer to ensure serviceability requirements of the structure. In spite of several proposed crack prediction models that have been used as the base for design codes, still a lack of certainty can be clearly felt in predicting cracking behavior of reinforced concrete. This is due to the fact that cracking is a very complex phenomenon in which numerous factors are involved, and it is always too cumbersome to take the effects of all these influential aspects into account. In order to acquire more insight into this issue, a comprehensive attempt has been made both experimentally and theoretically here in this study. This research is primarily dealing with cracks that develop under monotonic increasing load which is the main cause for the formation of wide cracks among other causes such as shrinkage or temperature. In this regard, several laboratory tests were conducted on a one meter wide strip of a tank wall. These experiments covered a range of loading configuration that would enable various combinations of stresses across the reinforced concrete section. Cracking behavior and water tightness of the slab were closely monitored and reported. Fiber reinforced polymers were shown to be a suitable means of remediation in reducing water leakage or recovering structural strength. A positive role of concrete autogenous healing on water leakage was investigated during the practical test. A comparison is made between experimental results and several recent well-known crack prediction models, through which their advantages and disadvantages are revealed and discussed. Several finite element models (FEM) have been successfully built with the aid of computer program ABAQUS/6.5 to capture the post-failure stress/strain condition in concrete and reinforcement, the results of which are perfectly matching with those obtained from experimental tests and theoretical calculations.

Reliability-Based Design of Torpedo Anchors

2010 ◽  
Author(s):  
Lui´s Volnei Sudati Sagrilo ◽  
Jose´ Renato Mendes de Sousa ◽  
Edison Castro Prates de Lima ◽  
Elisabeth Campos Porto ◽  
Jane Vieira Volota˜o Fernandes ◽  
...  
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Prediction Models ◽  
Experimental Tests ◽  
Structural Safety ◽  
Safety Factors ◽  
Reliability Based Design ◽  
Numerical Tools ◽  
Offshore Oil Industry ◽  
Offshore Oil

The use of powerful numerical tools based on the finite element method has been improving the prediction of the ultimate bearing capacity of fixed anchors applied in the offshore oil industry. One of the main achievements of these numerical tools is the reduction of the uncertainty related to the bearing capacity prediction of these anchors. Therefore, it is possible to reduce the design safety factors values that have been calibrated based on prediction models with higher uncertainty, without impairing the original level of the structural safety. This paper presents a reliability-based safety factors calibration study for the design of torpedo anchors considering the statistical model uncertainty evaluated using the results from some experimental tests performed by PETROBRAS and their correspondent finite-element based numerical estimates.

Semi-analytical prediction and experimental evaluation of material damping in wood panels

Holzforschung ◽  
2013 ◽  
Vol 67 (3) ◽  
pp. 333-343 ◽  
Author(s):  
Nathalie Labonnote ◽  
Anders Rønnquist ◽  
Kjell Arne Malo
Keyword(s):  
Material Properties ◽  
Strain Energy ◽  
Goodness Of Fit ◽  
Prediction Models ◽  
Mode Shapes ◽  
Analytical Prediction ◽  
Material Damping ◽  
Intrinsic Properties ◽  
Laminated Veneer Lumber ◽  
Loss Factors

Abstract A semi-analytical prediction model of material damping in timber panels has been developed. The approach is derived from the strain energy method and the input is based on loss factors, which are intrinsic properties of the considered materials, together with other material properties and mode shape integrals, whose calculation can easily be implemented in most finite element codes. Experimental damping evaluations of particleboards, oriented strand boards, and structural laminated veneer lumber panels are presented. Fair goodness of fit between the experimental results and the prediction models – relying only on the loss factors and the mode shapes – reveals an efficient approach for the prediction of material damping in timber panels including all boundary conditions.

scholarly journals Size Effect in FRP Shear-Strengthened RC Beams: Design Models Versus Experimental Data

CivilEng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 874-894
Author(s):  
Zine El Abidine Benzeguir ◽  
Omar Chaallal
Keyword(s):  
Size Effect ◽  
Prediction Models ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Shear Resistance ◽  
Design Guidelines ◽  
Resistance Force ◽  
Rc Beams ◽  
Ultimate Shear Strength ◽  
Experimental Findings

Numerous studies on the size effect have been devoted to reinforced concrete (RC) beams. They have shown that increasing the beam size leads to a decrease in ultimate shear strength (stress) at failure. This is reflected in the design model of most current international codes and guidelines, where the size effect is taken into consideration by reducing concrete contribution to the shear resistance (force). In contrast, the size effect of RC beams strengthened with externally bonded (EB) fibre-reinforced polymer (FRP) is not fully documented, and very few experimental studies have been devoted to the phenomenon. The objective of this study was to evaluate the accuracy of the current code and guideline models in terms of the size effect on the EB-FRP contribution to shear resistance. To this end, a database of experimental findings on the size effect in EB-FRP-strengthened beams was built based on the reported literature, as well as our own experimental tests. The data were analysed and compared with the predictions of six current codes and design guidelines to assess their accuracy. Experimental results clearly revealed the presence of a size effect related to EB-FRP as well as the existence of interaction between internal stirrups and EB-CFRP. Based on analysis of the collected experimental test results, the study clearly revealed that the predictions of current codes and guidelines overestimate the contribution of EB-FRP systems to shear resistance. The size effect tends to exacerbate this overestimation as the effective depth (d) of the beams increases. Therefore, until the size effect for RC beams strengthened in shear with EB-FRP is captured by the prediction models, current codes and design guidelines are to be used with caution.

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