scholarly journals Seismic analysis of uplift-available gantry crane subjected to extreme earthquake loads

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Q. Peng
Keyword(s):  
Seismic Analysis ◽  
Incident Angle ◽  
Ground Motions ◽  
Near Field ◽  
Time History ◽  
Gantry Crane ◽  
Inelastic Behavior ◽  
Variable Model ◽  
Highly Nonlinear ◽  
Inelastic Responses

This paper aims to investigate the uplift behavior coupled with the non-linearity both in material properties and in geometry deformations of a typical gantry crane under near-field ground motions. First, the highly nonlinear and time variable model considering the uplift-available boundary condition based on the theory of Mohr-Coulomb friction is established of the gantry crane using the OpenSees platform. Then, a series of time-history analyses on this model structure is performed under three near-field seismic loadings with different exceeding probabilities. Furthermore, the comparison between the uplift-available gantry crane and the fixed crane is also carried out to provide in-depth insight into the structural responses under different boundary conditions. Finally, coupling with the material and geometry inelastic behavior, the uplift response process is modeled in this paper and the seismic incident angle from 0 up to 360 degrees is also examined to quantitatively confirm the prioritization of uplift event and the other inelastic responses. And the new conception of uplift probability is first proposed herein to reveal the nature of uncertainty. It is found that uplift behavior plays an essential role in designing and evaluating the seismic performance of gantry cranes; further, the uplift response increases the seismic demand of the gantry crane structure and even causes collapse under strong ground motions.

scholarly journals Assessing Seismic Performance of Gantry Crane Subjected to Near-Field Ground Motions Using Incremental Dynamic and Endurance Time Analysis Methods

2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Qihui Peng ◽  
Wen-ming Cheng ◽  
Peng Guo ◽  
Hongyu Jia
Keyword(s):  
Seismic Performance ◽  
Incident Angle ◽  
Ground Motions ◽  
Near Field ◽  
Maxwell Model ◽  
Element Model ◽  
Gantry Crane ◽  
Time Analysis ◽  
Viscous Dampers ◽  
Endurance Time

Assessing the seismic performance of the gantry crane is significant since the structure is more vulnerable to earthquakes with the increase in size and lifting weight capacity. This paper aims to investigate the seismic response of the gantry crane incorporating near-field ground motions using incremental dynamic and endurance time analysis (IDA and ETA) methods. To model the structure accurately, a nonlinear finite element model of the gantry crane considering the viscoelastic effect is developed in the OpenSees platform. Then, the IDA method is also carried out for a comparison with the ETA method. The results of the two methods are consistent with a correlation of 93.9% while the computational demand of the ETA method is much less than those of the IDA method. To study further, both the seismic incident angle and the application of viscous dampers using the Maxwell model are analyzed and discussed in detail. The results show that seismic incident angle has a distinct influence on the maximum seismic displacement and viscous dampers can significantly reduce the seismic demand of the gantry crane. These findings support the seismic design of gantry cranes and evaluate the structural seismic performance efficiently.

DAMAGE EVOLUTION SPECTRA FOR SEISMIC ANALYSIS OF HIGH-RISE BUILDINGS

2012 ◽  
Vol 06 (03) ◽  
pp. 1250021
Author(s):  
Y. B. HO ◽  
J. S. KUANG
Keyword(s):  
Damage Evolution ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Time History ◽  
Tall Buildings ◽  
Response Spectra ◽  
Seismic Damage ◽  
Analysis And Design ◽  
High Rise ◽  
Earthquake Ground Motions

Seismic response spectra are amongst one of the most important tools for characterizing earthquake ground motions. In design practice, the response spectra are presented without including any load history, hence the nonlinear analysis of structures based solely on conventional earthquake response spectra is theoretically unsound, particularly for long-period or vertically irregular high-rise buildings. In this paper, a concept of seismic damage evolution is introduced and the method of analysis for characterizing the process of seismic damage to structures under earthquakes is presented. Seismic damage evolution spectra for analysis and design of high-rise buildings are then developed as an effective means of describing and simplifying earthquake ground motions. These spectra are shown to be very useful in selecting the ground motion-time history and, particularly, validating the equivalent static-load analysis and design of high-rise buildings under near-fault pulse-like ground motions. Case studies of the seismic inelastic performance of two vertically irregular, tall buildings are presented considering the seismic damage evolution spectra.

scholarly journals Fragility Analysis of Gantry Crane Subjected to Near-Field Ground Motions

2020 ◽  
Vol 10 (12) ◽  
pp. 4219
Author(s):  
Qihui Peng ◽  
Wenming Cheng ◽  
Hongyu Jia ◽  
Peng Guo
Keyword(s):  
Failure Probability ◽  
Structural Damage ◽  
Fragility Curves ◽  
Damage Control ◽  
Ground Motions ◽  
Near Field ◽  
Vertical Component ◽  
Gantry Crane ◽  
Fe Model ◽  
Demand Model

A gantry crane located in a near-field earthquake-prone area is selected in this paper as an example, and the nonlinear finite element (FE) model is used considering the material nonlinearity including plastic hinges and the second order (P − Δ ) effect with a comprehensive consideration of the components including sill beams, support beams, legs, and trolley girders. The local displacement ratio (LDR) and deflection ratio (DR) are proposed as demand measures (DMs) of the gantry crane, which are utilized to construct a probabilistic seismic demand model (PSDM). Then, the capacity limit states for the gantry crane are defined in this study by performing pushover analysis (POA), known as serviceability, damage control, and collapse prevention, respectively. Moreover, the operating capacity of the crane during an earthquake is further investigated and quantified by operating seismic peak ground acceleration, which is defined as the maximum acceleration when the failure probability is 50%. Finally, the fragility curves and the failure probability of the gantry crane are derived by the above definitions, all of which are pioneering in the seismic design of gantry cranes subjected to near-field ground motions. Some major conclusions are drawn that the horizontal component of an earthquake has a more notable effect on the structural damage of the gantry crane compared to the vertical component, and incremental dynamic analysis can take seismic uncertainty into account and quantify the deformation of gantry crane in more detail.

EVALUATION OF CAPACITY SPECTRUM METHOD IN ESTIMATING SEISMIC DEMANDS OF TRIPLE PENDULUM BEARINGS UNDER NEAR-FIELD GROUND MOTIONS

2014 ◽  
Vol 14 (02) ◽  
pp. 1350062 ◽  
Author(s):  
GHOLAMREZA GHODRATI AMIRI ◽  
PEJMAN NAMIRANIAN
Keyword(s):  
Ground Motions ◽  
Near Field ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Base Shear ◽  
Capacity Spectrum Method ◽  
Seismic Demands ◽  
Spectrum Method ◽  
Capacity Spectrum ◽  
Triple Pendulum

Simplified methods for analyzing seismically isolated structures are always used either as a design procedure or as checking criteria for the results of time history procedure. The main purpose of this study is to evaluate the accuracy of one of these methods, the capacity spectrum method (CSM), in predicting the seismic demands, such as isolator displacement and maximum base shear force, of structures with triple pendulum bearings (TPBs) under bidirectional near-field ground motions. By comparing the results of this method with those of the nonlinear time history analysis (NTHA), it can be concluded that the CSM is able to predict the maximum isolator displacement and base shear of the structure with acceptable accuracy. It should be noted that for softer soil site conditions, the values of demand calculated by CSM are sometimes underestimated compared with the results of NTHA, especially when the effective period of system exceeds 3.0 s or when the TPB works on the fifth regime of its pendulum mechanism.

scholarly journals Seismic Evaluation of Self-Centering Bi-Rocking Walls via Micro Modeling of Rocking Joints: Locating the Rocking Section

2021 ◽  
Author(s):  
Vahid Broujerdian ◽  
Esmaeil Mohammadi Dehcheshmeh
Keyword(s):  
Ground Motions ◽  
Near Field ◽  
Time History ◽  
Comparative Investigation ◽  
Seismic Evaluation ◽  
Higher Modes ◽  
High Rise ◽  
The Moment ◽  
Nonlinear Time History ◽  
Rocking Walls

Abstract The rocking concrete shear wall is one of the new self-centering seismic systems applied in high-rise buildings. To reduce the effects of higher modes on base-rocking walls, the idea of using multiple rocking walls has been evolved. This paper presents a comparative investigation on the seismic performance of base-rocking and bi-rocking wall systems. To this aim, structures of 4-, 8-, 12-, 16-, and 20- stories have been evaluated subjected to three sets of seismic earthquake records including 22 Far Field (FF), 14 Near Field (NF) with pulse, and 14 Near Field (NF) no-pulse ground motions. The nonlinear time-history analyses were conducted in two directions using OpenSEES software. To determine the appropriate location of rocking section in bi-rocking walls, one-quarter (R2-M1), one-half (R2-M2), and three-quarter (R2-M3) models were examined. The obtained results revealed that R2-M3 model is not efficient in reducing the effects of higher modes. However, R2-M2 model in high-rise buildings under FF and NF-no-pulse records could be effective in decreasing the moment by a maximum of nearly 41% and the shears by a maximum of 25% and 18%, respectively. Furthermore, the results showed that bi-rocking walls could not be effective in reducing the influence of higher modes under NF-pulse ground motions. Generally, the residual drifts were negligible in all the rocking systems under study.

scholarly journals Seismic Response of Nonseismically Designed Reinforced Concrete Low Rise Buildings

2018 ◽  
Vol 24 (4) ◽  
pp. 112
Author(s):  
Thamir K. Mahmoud ◽  
Hayder A. Al-Baghdadi
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Inelastic Behavior ◽  
Base Shear ◽  
Earthquake Excitation ◽  
Inelastic Responses ◽  
Concrete Damage

In this paper, the time-history responses of a square plan two-story reinforced concrete prototype building, considering the elastic and inelastic behavior of the materials, were studied numerically. ABAQUS software was used in three-dimensional (3D) nonlinear dynamic analysis to predict the inelastic response of the buildings. Concrete Damage Plasticity Model (CDPM) has been used to model the inelastic behavior of the reinforced concrete building under seismic excitation. The input data included geometric information, material properties, and the ground motion. The building structure was designed only for gravity load according to ACI 318 with non-seismically detailing requirements. The prototype building was subjected to El Centro 1940 NS earthquake at different amplitudes (PGA=0.05g, PGA=0.15g, and PGA=0.32g). The elastic and inelastic responses of the 3D numerical model of the same building were evaluated. The differences between the elastic and inelastic displacements and base shear forces were analyzed. It was found from the results that base shear responses are significantly more sensitive to the numerical model of analysis than displacement responses. The evaluation showed that the base shear force and displacement responses of a two-story R.C. building subjected to severe earthquake excitation are very sensitive to the numerical model used whether it is elastic or inelastic.  

scholarly journals Evaluation of Seismic Fragility of Weir Structures in South Korea

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Bu Seog Ju ◽  
WooYoung Jung
Keyword(s):  
Tensile Stress ◽  
Seismic Vulnerability ◽  
Linear Time ◽  
Ground Motions ◽  
Near Field ◽  
Time History ◽  
Fe Model ◽  
Mass Concrete ◽  
Far Field ◽  
Ground Acceleration

In order to reduce earthquake damage of multifunctional weir systems similar to a dam structure, this study focused on probabilistic seismic risk assessment of the weir structure using the fragility methodology based on Monte Carlo simulation (MCS), with emphasis on the uncertainties of the seismic ground motions in terms of near field induced pulse-like motions and far field faults. The 2D simple linear elastic plain strain finite element (FE) model including soil structure foundations using tie connection method in ABAQUS was developed to incorporate the uncertainty. In addition, five different limit states as safety criteria were defined for the seismic vulnerability of the weir system. As a consequence, the results obtained from multiple linear time history analyses revealed that the weir structure was more vulnerable to the tensile stress of the mass concrete in both near and far field ground motions specified earthquake hazard levels. In addition, the system subjected to near field motions was primarily more fragile than that under far field ground motions. On the other hand, the probability of failure due to the tensile stress at weir sill and stilling basin showed the similar trend in the overall peak ground acceleration levels.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

Seismic response analysis of steel–concrete hybrid wind turbine tower

2021 ◽  
pp. 107754632110075
Author(s):  
Junling Chen ◽  
Jinwei Li ◽  
Dawei Wang ◽  
Youquan Feng
Keyword(s):  
Wind Turbine ◽  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Seismic Action ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Wind Turbine Tower ◽  
Ground Types ◽  
Nonlinear Time History

The steel–concrete hybrid wind turbine tower is characterized by the concrete tubular segment at the lower part and the traditional steel tubular segment at the upper part. Because of the great change of mass and stiffness along the height of the tower at the connection of steel segment and concrete segment, its dynamic responses under seismic ground motions are significantly different from those of the traditional steel tubular wind turbine tower. Two detailed finite element models of a full steel tubular tower and a steel–concrete hybrid tower for 2.0 MW wind turbine built in the same wind farm are, respectively, developed by using the finite element software ABAQUS. The response spectrum method is applied to analyze the seismic action effects of these two towers under three different ground types. Three groups of ground motions corresponding to three ground types are used to analyze the dynamic response of the steel–concrete hybrid tower by the nonlinear time history method. The numerical results show that the seismic action effect by the response spectrum method is lower than those by the nonlinear time history method. And then it can be concluded that the response spectrum method is not suitable for calculating the seismic action effects of the steel–concrete hybrid tower directly and the time history analyses should be a necessary supplement for its seismic design. The first three modes have obvious contributions on the dynamic response of the steel–concrete hybrid tower.

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