scholarly journals Seismic Behavior and Force-Displacement Characterization of Neotype Column-Slab High Piers

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
YanQun Zhou ◽  
YeZhi Zhang ◽  
MeiXin Ye ◽  
MengSi Zhan
Keyword(s):  
Seismic Behavior ◽  
Large Scale ◽  
Scale Model ◽  
Test Results ◽  
Lateral Displacements ◽  
High Pier ◽  
Experimental Values ◽  
Large Scale Tests ◽  
Force Displacement

The seismic behavior and plasticity spreading of a neotype column-slab high pier are researched in this paper. Four scale model tests of a web slab with two boundary columns are carried out under cyclic inelastic lateral displacements simulating seismic response. The test results show that the neotype column-slab high pier has strong and stable bearing capacity, good ductility, and energy dissipation capacity. The experimental values pertaining to the spread of plasticity are derived. An approach for deriving the spread of plasticity analytically is deduced and applied to the four tests. This method accurately assesses a pier’s spread of plasticity for most ductility levels. At nearly all ductility levels, the mean difference between analytical assessments of the spread of plasticity and results from 4 large-scale tests is 12% with a 9% coefficient of variation.

scholarly journals Practical Soil-Shallow Foundation Model for Nonlinear Structural Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Moussa Leblouba ◽  
Salah Al Toubat ◽  
Muhammad Ekhlasur Rahman ◽  
Omer Mugheida
Keyword(s):  
Structural Analysis ◽  
Cyclic Loading ◽  
Experimental Test ◽  
Large Scale ◽  
Shallow Foundation ◽  
Scale Model ◽  
Test Results ◽  
Nonlinear Structural Analysis ◽  
Large Scale Model ◽  
Foundation Model

Soil-shallow foundation interaction models that are incorporated into most structural analysis programs generally lack accuracy and efficiency or neglect some aspects of foundation behavior. For instance, soil-shallow foundation systems have been observed to show both small and large loops under increasing amplitude load reversals. This paper presents a practical macroelement model for soil-shallow foundation system and its stability under simultaneous horizontal and vertical loads. The model comprises three spring elements: nonlinear horizontal, nonlinear rotational, and linear vertical springs. The proposed macroelement model was verified using experimental test results from large-scale model foundations subjected to small and large cyclic loading cases.

Material Characterization and Modeling of High Strength PM Steel

2011 ◽  
Vol 337 ◽  
pp. 766-769
Author(s):  
Sachin B Mirajkar ◽  
K. Gopinath ◽  
Raghu V. Prakash
Keyword(s):  
Material Characterization ◽  
High Strength ◽  
Fine Tuning ◽  
Density Range ◽  
Test Results ◽  
Structural Alloy ◽  
Gtn Model ◽  
Experimental Values ◽  
Porosity Characterization

Powder Metallurgy (PM) component properties are influenced by the pore morphology, size, size-distribution and pore content [1]. Structural alloy Astaloy LH mechanical properties are characterized for density range 6.3 to 7.1 g/cm3. Porosity characterization of the material is also done using ASTM standard. In the first phase, an attempt is made to predict the tensile property using Gurson-Tvergaard-Needleman (GTN) model and FEM. The prediction is verified with tensile test results. It is observed that after fine tuning the parameters in the model, the prediction is found to be close to experimental values.

scholarly journals Design Criterion and a Technical Approach for the Controlled Seismic Behavior of Continuous Girder Bridges

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Hao Gao ◽  
Yanchen Song ◽  
Junjie Wang ◽  
Huijie Liu
Keyword(s):  
Seismic Behavior ◽  
Large Scale ◽  
Experimental Studies ◽  
Design Criterion ◽  
Hysteresis Curve ◽  
Test Results ◽  
Friction Behavior ◽  
Alternative Scheme ◽  
Girder Bridges ◽  
Space Requirements

Seismic design involving “fuse components” between the superstructure and substructure can improve the seismic performance of continuous girder bridges during strong earthquakes by ensuring an elastic working state. The mechanical properties of the “fuse components” directly affect the seismic behavior of continuous girder bridges, and many theoretical and experimental studies of isolation devices to achieve the controlled seismic behavior of continuous girder bridges have been carried out, and some devices are in use in large-scale construction projects. However, there is a lack of evidence from structures that have been subject to earthquakes. Test results show that the shear behavior of isolation bearings is unpredictable and the friction behavior is uncontrollable. Further, limiting devices often suffer from an insufficient deformation capacity and have large space requirements. Therefore, we propose a new type of spherical steel bearing and two kinds of large-stroke steel damping devices with different space requirements. The full-scale test results reveal that the bearing has strong controllability with respect to shearing, stable friction behavior after fracture, and little unpredictability in the friction-based processes. Furthermore, the large-stroke steel damping device shows a full hysteresis curve and excellent energy dissipation characteristics. Finally, using a continuous girder bridge as an example and combined with the results of mechanical tests, the effectiveness of the controlled design criterion was verified using numerical simulations. The calculated results show that, compared with conventional fixed bearings, the shear and bending moments are decreased by 60% and 53%, respectively, and the ratio of both the shear and bending moment response of the pier bottom to its capacity is less than 0.5. However, the ratio of the maximum deformation of the damper to its capacity is only 0.28, and the residual displacement is 0.01 m. Therefore, an alternative scheme is provided for postearthquake maintenance and replacement.

Further Post Test Analysis and Comparison of STYLE MU-2 Test Results

2016 ◽  
Author(s):  
Peter James ◽  
Michael Ford
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Large Scale ◽  
Welding Residual Stress ◽  
Test Results ◽  
Residual Stress Field ◽  
Test Analysis ◽  
Ductile Crack Growth ◽  
Post Test ◽  
Large Scale Tests

Within the EU 7th framework programme, STYLE, a number of large-scale tests have been performed. One of these tests, Mock-Up 2 (MU-2), was performed on a through wall crack located at a repair weld adjacent to a multi-pass girth weld. The aim of MU-2 was to investigate ductile crack growth under conditions with significant levels of welding residual stress. Post-test analysis of these tests has been presented by different partners within the programme. This has led to some differences in the interpretation of the results and a degree of scatter in the resulting predictions. The post-test analyses performed at the different UK establishments indicated that the ductile initiation may have been influenced by the presence of the residual stress field. However, the different investigations do not provide consistent estimates of the magnitude of this effect, nor do they provide equivalent results when considering the load-deformation of the pipe. It was therefore agreed that it would be beneficial to understand the source of these differences in order to provide an improved prediction. Further post-test finite element analyses of the MU-2 test have therefore been performed to consider: 1) potential variations in material properties adopted, 2) the approach to better include the predicted residual stress field, and 3) the introduction of the defect into the stress field. This range of analyses has helped clarify the differences in the analyses performed and has provided further insight to the test results.

scholarly journals Multi-directional force–displacement response of underground pipe in sand

2016 ◽  
Vol 53 (11) ◽  
pp. 1763-1781 ◽  
Author(s):  
Jai K. Jung ◽  
Thomas D. O’Rourke ◽  
Christina Argyrou
Keyword(s):  
Large Scale ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Movement Direction ◽  
Saturated Sand ◽  
Partially Saturated ◽  
Analytical Results ◽  
Partially Saturated Sand ◽  
Large Scale Tests ◽  
Force Displacement

A methodology is presented to evaluate multi-directional force–displacement relationships for soil–pipeline interaction analysis and design. Large-scale tests of soil reaction to pipe lateral and uplift movement in dry and partially saturated sand are used to validate plane strain, finite element (FE) soil, and pipe continuum models. The FE models are then used to characterize force versus displacement performance for lateral, vertical upward, vertical downward, and oblique orientations of pipeline movement in soil. Using the force versus displacement relationships, the analytical results for pipeline response to strike-slip fault rupture are shown to compare favorably with the results of large-scale tests in which strike-slip fault movement was imposed on 250 and 400 mm diameter high-density polyethylene pipelines in partially saturated sand. Analytical results normalized with respect to maximum lateral force are provided on 360° plots to predict maximum pipe loads for any movement direction. The resulting methodology and dimensionless plots are applicable for underground pipelines and conduits at any depth, subjected to relative soil movement in any direction in dry or saturated and partially saturated medium to very dense sands.

Nonlinear Wheelset Forces in Flange Contact—Part 2: Measurements Using Dynamically Scaled Models

1979 ◽  
Vol 101 (3) ◽  
pp. 247-255 ◽  
Author(s):  
L. M. Sweet ◽  
J. A. Sivak ◽  
W. F. Putman
Keyword(s):  
Lateral Force ◽  
Contact Forces ◽  
Scale Model ◽  
Rail Vehicle Dynamics ◽  
Curving Performance ◽  
Lateral Displacements ◽  
Scaled Models ◽  
Force Displacement ◽  
Yaw Moment ◽  
Contact Part

This paper presents new experimental methods for the study of rail vehicle dynamics through the use of scaled models on tangent track, and the application of these techniques to the measurement of nonlinear wheelset force/displacement relations in steady-state. These relations are important to the analysis of wheelset response to track inputs, curving performance of trucks, and wheelclimb derailment. A one-fifth scale model instrumented wheelset with new wheel profiles is used, with similitude scaling of the contact forces achieved through use of a polycarbonate resin for the contact surfaces. Data are presented for wheelset lateral force and yaw moment for the nonlinear range of wheelset lateral displacements and yaw angles, including flange contact. The measured data validate the analytical model presented in Part 1 of this paper, based on nonlinear wheel/rail contact geometry, creep forces with adhesion limits, and wheelset kinematics. A criterion for wheelclimb derailment is presented and verified experimentally.

Characterization of Adhesive Joints Under Shock-Wave Loading

2016 ◽  
Author(s):  
Salih Yildiz ◽  
Daniel Shaffren ◽  
Doug Jahnke ◽  
Feridun Delale ◽  
Yiannis Andreopoulos
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Large Scale ◽  
Element Model ◽  
Adhesive Joints ◽  
Failure Behavior ◽  
Transient Strain ◽  
Experimental Values ◽  
First Time

The failure behavior of adhesive joints under shock-wave loadings was investigated in a large scale shock tube facility for the first time. An overlapping specimen consisting of two parts, one circular patch and one supporting ring were bonded together in a specially designed jig. Sub-miniature semi-conductor strain gauges were attached on the specimen to monitor the transient strain on specific locations. A high speed camera was used to record the detachment of the patch from the ring. Image processing tool was used to track the position of the patch as a function of time. This information yield estimates of velocity, acceleration and kinetic energy of the patch. A finite element model was also created and the computation results were compared to the experimental values obtained.

Reinforced concrete slab-column edge connections with shear studs

2000 ◽  
Vol 27 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Monir H Soliman
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Slab ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Test Parameters ◽  
Flexural Reinforcement ◽  
Large Scale Tests

The paper reports the results of an experimental investigation on the influence of shear studs on the behaviour of reinforced concrete slab-column edge connections with openings. The test parameters were the location of openings around the column, the size of openings, and the existence of shear reinforcement. The objective of the paper is to present and discuss the results of large-scale tests on slabs with shear stud reinforcement and compare these test results with those of tests on identical slabs but without shear reinforcement. All tested slabs contained same amounts of typical flexural reinforcement (ACI 318-95 and CSA A23.3-94). The presented test results can be used for studying the behaviour of slab-column connections and for calibration of the predictive models.Key words: reinforced concrete, edge connections, flat concrete plates, punching shear, shear strength, openings, failure, shear studs, shear reinforcement.

Large-Scale Model Investigation for Monopile Decommissioning of Offshore Wind Turbines: Overpressure and Vibratory Pile

2021 ◽  
Author(s):  
Nils Hinzmann ◽  
Patrick Lehn ◽  
Jörg Gattermann
Keyword(s):  
Large Scale ◽  
Planning Process ◽  
Complete Removal ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbines ◽  
Large Scale Model ◽  
First Results ◽  
Set Up ◽  
Large Scale Tests

Abstract As of now, only a small number of offshore foundations, related to offshore wind energy, were decommissioned in Europe. With a diameter up to nine meter, an embedment of about 40 meter and a set up effect over 25 years, the necessary force to pull the pile out of the seabed can be assumed, if at all determinable, to be enormous. The piles that were decommissioned were cut beneath the mud line, which leaves approximately one third of the foundation permanently in the seabed. Different methods and techniques for a complete removal of offshore pile foundation are currently investigated within the project DeCoMP. Vibratory extraction aims for a reduction of the pile skin friction by creating a layer of less density between the pile shaft and pending soil. During the design and planning process for vibratory installation or extraction a drivability prediction is a key element. In order to identify and characterize soil parameter for the numerical simulation of a drivability prediction, large-scale tests are performed by the Institute of Geomechanics and Geotechnics of the Technische Universität Braunschweig (IGG-TUBS) [1]. In this paper first results of pilot tests with two vibrators are presented and key elements such as crane uplift, frequency and acceleration displayed.

Strength and Ductility of Reactive Powder Concrete Columns

2009 ◽  
Vol 417-418 ◽  
pp. 621-624 ◽  
Author(s):  
Guan Yuan Zhao ◽  
Wen Xiu Hao
Keyword(s):  
Analytical Model ◽  
Seismic Behavior ◽  
Concrete Columns ◽  
Reactive Powder Concrete ◽  
Test Results ◽  
Acceptable Accuracy ◽  
Reactive Powder ◽  
Relationship Of ◽  
Force Displacement ◽  
Strength And Ductility

Two hollow rectangular bridge columns with Reactive powder concrete (RPC) were tested under a cyclically reversed horizontal load. Based on the test results, the seismic behavior of such columns was presented. An analytical model was developed to predict the force-displacement relationship of specimens. The test results were also compared to the proposed analytical model. It was found that the ductility factors of the specimens are over 4.0, and the proposed analytical model can predict the force-displacement relationship of such columns with acceptable accuracy.

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