Mathematical modelling of the container cranes under seismic loading and proving by shake table

This paper is concerned with the verification of mathematical modeling of the container cranes under earthquake loadings with shake table test results. Comparison of the shake table tests with the theoretical studies has an important role in the estimation of the seismic behavior of the engineering structures. For this purpose, a new shake table and mathematical model were developed. Firstly, a new physical model is directly fixed on the shake table and the seismic response of the container crane model against the past earthquake ground motion was measured. Secondly, a four degrees-of-freedom mathematical model is developed to understand the dynamic behaviour of cranes under the seismic loadings. The results of the verification study indicate that the developed mathematical model reasonably represents the dynamic behaviour of the crane structure both in time and frequency domains. The mathematical model can be used in active-passive vibration control studies to decrease structural vibrations on container cranes.

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Failure Analysis of Piping Systems With Thinned Elbows on Tri-Axial Shake Table Tests

ASME 2011 Pressure Vessels and Piping Conference: Volume 8 ◽

10.1115/pvp2011-57580 ◽

2011 ◽

Author(s):

Tadahiro Shibutani ◽

Izumi Nakamura ◽

Akihito Otani

Keyword(s):

Plastic Strain ◽

Failure Analysis ◽

Seismic Loading ◽

Fracture Analysis ◽

Piping System ◽

Shake Table ◽

Loading History ◽

Damage Factor ◽

Shake Table Tests ◽

Piping Systems

This paper presents a computational failure analysis of piping systems with and without thinned elbows on tri-axial shake table tests. In a previous experimental study, two piping models, a sound piping system and a degraded piping system with thinned elbows, were assessed. The sound piping system was found to failed at the elbow flank due to in-plane cyclic bending, whereas the degraded system failed at the end of the elbow due to excessive pipe ovalization. In the present study, finite element (FE) models of elbows were developed in order to carry out fracture analysis. The measured displacements of seismic motions were used as the boundary conditions for FE models. In the sound piping system, plastic strain concentrated at the flank of the elbow due to in-plane bending. The cumulative damage factor was calculated from the fatigue curve and Miner’s rule. The effect of ratcheting was also considered. In the failed elbow, the calculated cumulative damage factor showed good agreement with experimental results. On the other hand, for the fracture analysis of the thinned elbow, the entire seismic loading history on the tri-axial shake table was considered, since the effect of pipe ovalization depends on loading history. The ovalization occurred at the elbow due to cumulative seismic loading. Consequently, the principal plastic strain began to concentrate at the end of the elbow. These FE results offer quantitative explanation for the observed failure modes in the degraded piping system.

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Failure Analysis of Piping Systems With Thinned Elbows on Tri-Axial Shake Table Tests

Journal of Pressure Vessel Technology ◽

10.1115/1.4028422 ◽

2014 ◽

Vol 137 (1) ◽

Author(s):

Tadahiro Shibutani ◽

Izumi Nakamura ◽

Akihito Otani

Keyword(s):

Plastic Strain ◽

Failure Analysis ◽

Seismic Loading ◽

Fracture Analysis ◽

Piping System ◽

Shake Table ◽

Loading History ◽

Damage Factor ◽

Shake Table Tests ◽

Piping Systems

This paper presents a computational failure analysis of piping systems with and without thinned elbows on tri-axial shake table tests. In a previous experimental study, two piping models, a sound piping system and a degraded piping system with thinned elbows, were assessed. The sound piping system was found to fail at the elbow flank due to in-plane cyclic bending, whereas the degraded system failed at the end of the elbow due to excessive pipe ovalization. In the present study, finite element (FE) models of elbows were developed in order to carry out fracture analysis. The measured displacements of seismic motions were used as the boundary conditions for FE models. In the sound piping system, plastic strain concentrated at the flank of the elbow due to in-plane bending. The cumulative damage factor was calculated from the fatigue curve and Miner's rule. The effect of ratcheting was also considered. In the failed elbow, the calculated cumulative damage factor showed good agreement with experimental results. On the other hand, for the fracture analysis of the thinned elbow, the entire seismic loading history on the tri-axial shake table was considered, since the effect of pipe ovalization depends on loading history. The ovalization occurred at the elbow due to cumulative seismic loading. Consequently, the principal plastic strain began to concentrate at the end of the elbow. These FE results offer quantitative explanation for the observed failure modes in the degraded piping system.

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Shake-Table Testing of a Full-Scale Two-Story Precast Wall-Slab-Wall Structure

Earthquake Spectra ◽

10.1193/072518eqs184m ◽

2019 ◽

Vol 35 (4) ◽

pp. 1583-1609 ◽

Cited By ~ 3

Author(s):

Emanuele Brunesi ◽

Simone Peloso ◽

Rui Pinho ◽

Roberto Nascimbene

Keyword(s):

Precast Concrete ◽

Seismic Loading ◽

Full Scale ◽

Wall Structure ◽

Shake Table ◽

Structural Members ◽

Concrete Wall ◽

Engineering Research ◽

Response Performance ◽

Precast Walls

Precast wall-slab-wall buildings can be found in many different earthquake-prone areas of the world. This type of building structure features no beams or columns but rather precast walls and slabs alone that are joined together by means of steel connectors and mortar, both of which will not necessarily prevent the formation of relative sliding between structural members when the structure is subjected to certain levels of horizontal excitation, rendering them particularly vulnerable to seismic loading. Given the scarce amount of information/data on the seismic behavior of these structures, a dynamic shake-table test was undertaken to investigate the response/performance of a full-scale two-story reinforced precast concrete wall-slab-wall structure, up to incipient/near collapse. The building mock-up was subjected to five test runs of progressively increased intensity and collapsed because of failure of the steel connectors used to join the longitudinal and transverse walls. Test data are openly available and archived at the Natural Hazards Engineering Research Infrastructure DesignSafe Data Depot.

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Experimental and Analytical Studies of Hospital Piping Assemblies Subjected to Seismic Loading

Earthquake Spectra ◽

10.1193/1.3672911 ◽

2012 ◽

Vol 28 (1) ◽

pp. 367-384 ◽

Cited By ~ 21

Author(s):

Arash E. Zaghi ◽

E. Manos Maragakis ◽

Ahmad Itani ◽

Elliott Goodwin

Keyword(s):

Experimental Data ◽

Dynamic Response ◽

Boundary Conditions ◽

Computational Model ◽

Seismic Loading ◽

Experimental Results ◽

Piping System ◽

Shake Table ◽

Inertial Effects ◽

Drift Ratio

The seismic characteristics of welded and threaded hospital piping assemblies were investigated with and without seismic restrainers under various intensities of seismic loading using a biaxial shake table. Experimental results showed that the restrainers limited the displacements; however, they did not reduce the acceleration responses. No leakage was detected in the welded assembly up to a drift ratio of 4.3%; however, threaded piping suffered minor leaks at a drift ratio of 2.2% and experienced connection failure at a drift ratio of 4.3%. A simplified computational model was developed and calibrated with experimental data using SAP2000. The effective stiffness of the seismic restrainers was determined to be 10% of full stiffness due to their initial slack. The analyses showed that the dynamic response of the piping system as braced in these experiments with similar boundary conditions was predominantly kinematic with minimal inertial effects.

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