scholarly journals Small-scale Geotechnical Testing Using a Six-axis Robot

2020 ◽  
Author(s):  
Zhefei Jin ◽  
Zhenhao Shi ◽  
James Hambleton
Keyword(s):  
Moving Objects ◽  
Force Measurement ◽  
Industrial Robot ◽  
Model Tests ◽  
Combined Loading ◽  
Small Scale ◽  
Multiple Components ◽  
Geotechnical Testing ◽  
Force Displacement ◽  
Machine Interaction

Single-gravity (1-g) small-scale testing is a widely used method to investigate geomechanics problems that involve the interactions between soils and objects (e.g., structures or machine parts). This letter presents a new approach for performing 1-g model tests where a six-axis industrial robot functions as a versatile actuator capable of moving objects along virtually arbitrary trajectories, while simultaneously tracking multiple components of force and moment acting on the objects. A performance evaluation confirms that the robot's motion control and force measurement are sufficiently accurate for geotechnical model tests. This assessment is completed through two benchmarking exercises: (1) determining the failure envelope of a strip foundation subjected to combined loading and (2) quantifying the force-displacement history for the soil cutting process (e.g., for applications in soil-machine interaction).

scholarly journals Pile Model Tests Using Strain Gauge Technology

2015 ◽  
Vol 37 (3) ◽  
pp. 49-52 ◽  
Author(s):  
Adam Krasiński ◽  
Tomasz Kusio
Keyword(s):  
Bearing Capacity ◽  
Axial Force ◽  
Strain Gauge ◽  
Force Measurement ◽  
Ground Level ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Pile Head ◽  
Pile Model

Abstract Ordinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine the total bearing capacity of the pile, without the knowledge of its distribution into the shaft and base resistances. Much more information can be obtained by carrying out a test of instrumented pile equipped with a system for measuring the distribution of axial force along its core. In the case of pile model tests the use of such measurement is difficult due to small scale of the model. To find a suitable solution for axial force measurement, which could be applied to small scale model piles, we had to take into account the following requirements: - a linear and stable relationship between measured and physical values, - the force measurement accuracy of about 0.1 kN, - the range of measured forces up to 30 kN, - resistance of measuring gauges against aggressive counteraction of concrete mortar and against moisture, - insensitivity to pile bending, - economical factor. These requirements can be fulfilled by strain gauge sensors if an appropriate methodology is used for test preparation (Hoffmann [1]). In this paper, we focus on some aspects of the application of strain gauge sensors for model pile tests. The efficiency of the method is proved on the examples of static load tests carried out on SDP model piles acting as single piles and in a group.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

scholarly journals Development of Small-Scale Fishway for Amur Stickleback by Hydraulic Model Tests

2013 ◽  
Vol 19 (1) ◽  
pp. 29-36
Author(s):  
Eiji Ichion ◽  
Tatsuya Noto ◽  
Ken Hiramatsu ◽  
Shunsuke Chono ◽  
Kunihiko Kitamura
Keyword(s):  
Hydraulic Model ◽  
Model Tests ◽  
Small Scale

Small‐Scale Model Tests of Structural Steel Assemblies

1989 ◽  
Vol 115 (8) ◽  
pp. 1999-2015 ◽  
Author(s):  
Benjamin J. Wallace ◽  
Helmut Krawinkler
Keyword(s):  
Structural Steel ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Small Scale Model

Evaluation of a Small and Fast Planing Boat’s Seakeeping Performance at the Design Stage

2015 ◽  
Author(s):  
Dong Jin Kim ◽  
Sun Young Kim
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Design Stage ◽  
Small Scale ◽  
Irregular Wave ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Scale Ratio ◽  
Free Running

Seakeeping performance of a planing boat should be sufficiently considered and evaluated at the design stage for its safe running in rough seas. Model tests in seakeeping model basins are often performed to predict the performance of full-scale planing boats. But, there are many limitations of tank size and wave maker capacity, in particular, for fast small planing boats due to small scale ratio and high Froude numbers of their scale models. In this research, scale model tests are tried in various test conditions, and results are summarized and analyzed to predict a 3 ton-class fast small planing boats designed. In a long and narrow tank, towing tests for a bare hull model are performed with regular head waves and long crested irregular head waves. Motion RAOs are derived from irregular wave tests, and they are in good agreements with RAOs in regular waves. Next, model ships with one water-jet propulsion system are built, and free running model tests are performed in ocean basins. Wave conditions such as significant heights, modal periods, and directions are varied for the free running tests. Motion RMS values, and RAOs are obtained through statistical approaches. They are compared with the results in captive tests for the bare hull model, and are used to predict the full-scale boat performances.

Drift of Piles Subjected to Cyclic Lateral Loading From a Varying Direction: System vs. Soil Element Behavior

2014 ◽  
Author(s):  
Christina Rudolph ◽  
Jürgen Grabe ◽  
Britta Bienen
Keyword(s):  
Cyclic Loading ◽  
Model Tests ◽  
Small Scale ◽  
Shear Tests ◽  
Centrifuge Testing ◽  
Scale Modeling ◽  
Highly Sensitive ◽  
Number Of Cycles ◽  
Laterally Loaded ◽  
Insight Into

Offshore monopiles are usually designed using the p-y method for cyclic loading. While the method works for static loading, it was not developed for high numbers of cycles. Since the turbines are highly sensitive towards tilting, cyclic loading must be considered. The static results should therefore be combined with results from cyclic model tests with a high number of cycles to account for the accumulation of displacement or rotation during the lifetime of these structures. These model tests can underestimate the accumulation, however, as it has recently been shown that a change of loading direction can increase the accumulation considerably. These results have been verified using small scale modeling and centrifuge testing. The results from modeling the full problem of a laterally loaded pile are compared here with results from cyclic simple shear tests with a change of shearing direction during the cyclic loading. For these tests, a newly developed apparatus is used. This allows further insight into the question how a soil can “retain a memory” of its loading history.

Controlling sand placement during the building of artificial islands

1984 ◽  
Vol 21 (2) ◽  
pp. 371-375 ◽  
Author(s):  
D. H. Shields ◽  
L. Domaschuk ◽  
D. W. Corkal ◽  
J. R. McCutchon
Keyword(s):  
Cost Saving ◽  
Low Cost ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Considerable Cost ◽  
Environmentally Safe ◽  
Considerable Cost Saving ◽  
Small Scale Model

A new way to construct artificial islands of sand is described. The method shows promise of considerable cost saving. The present high cost of island building is due to the difficulty of making underwater sand slopes steep. Simply dumping sand into the ocean results in slopes of from 12 to 15 horizontal to 1 vertical. These shallow slopes have enormous implications in terms of sand volume and cost. The sand can be tremied into place to form a steep-sided ring or bund. Handling large quantities of sand in this way is expensive. Small-scale model tests show that if the sand is mixed with certain chemicals the resulting 'cohesion' enables the sand to fall through seawater as a block, with little dispersion. Steep underwater slopes result. Low-cost, nontoxic (environmentally safe) chemicals were used in the experiment. Keywords: construction, artificial islands, sand, oceans, dredging.

Pipeline plough performance in sand waves. Part 1: model testing

2010 ◽  
Vol 47 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Mark Fraser Bransby ◽  
Michael Brown ◽  
Andrew Hatherley ◽  
Keith Lauder
Keyword(s):  
Model Testing ◽  
Model Tests ◽  
Scale Model ◽  
Soil Conditions ◽  
Small Scale ◽  
Offshore Pipelines ◽  
Sand Waves ◽  
Increased Risk ◽  
Small Scale Model ◽  
Spoil Heaps

Offshore pipelines are often buried in the seabed by ploughing a trench, placing the pipe at the base, and then backfilling. The ploughing operation is critical in terms of cost and project time, with increased risk due to uncertain soil conditions or geohazards. One problem that can be encountered is the presence of sand waves or megaripples on the seabed surface. This may affect the progress of the plough, prevent the plough from generating a level trench or modify the size of the spoil heaps for backfilling. These aspects have been investigated by conducting a series of small-scale model tests in the laboratory. These have revealed information about the plough kinematics and the resulting trench conditions when ploughing in sand waves with different wavelengths and amplitudes. It is shown that it may be possible to plough through regions of sand waves and estimate likely plough performance by knowing the sand wavelength and amplitude relative to the plough size.

scholarly journals An automated system to mount cryo-cooled protein crystals on a synchrotron beamline, using compact sample cassettes and a small-scale robot

2002 ◽  
Vol 35 (6) ◽  
pp. 720-726 ◽  
Author(s):  
Aina E. Cohen ◽  
Paul J. Ellis ◽  
Mitchell D. Miller ◽  
Ashley M. Deacon ◽  
R. Paul Phizackerley
Keyword(s):  
Synchrotron Radiation ◽  
Industrial Robot ◽  
Automated System ◽  
Small Scale ◽  
Compact Sample ◽  
Long Term Storage ◽  
Radiation Laboratory ◽  
And Storage ◽  
Term Storage

An automated system for mounting and dismounting pre-frozen crystals has been implemented at the Stanford Synchrotron Radiation Laboratory (SSRL). It is based on a small industrial robot and compact cylindrical cassettes, each holding up to 96 crystals mounted on Hampton Research sample pins. For easy shipping and storage, the cassette fits inside several popular dry-shippers and long-term storage Dewars. A dispensing Dewar holds up to three cassettes in liquid nitrogen adjacent to the beamline goniometer. The robot uses a permanent magnet tool to extract samples from, and insert samples into a cassette, and a cryo-tong tool to transfer them to and from the beamline goniometer. The system is simple, with few moving parts, reliable in operation and convenient to use.

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