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

Abstract

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.

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

“…To quantificationally evaluate the seismic response of the gantry crane, a damage measure called local displacement ratio (LDR) is utilized [12], the definition of which is shown as follows:…”

“…Yazici and Oktay et al [9][10][11] studied the active vibration control of container cranes against earthquakes by varied controllers. ere are very few studies focused on the structural seismic response of gantry crane: Peng et al [12] developed the fragility curves of a gantry crane based on the incremental dynamic analysis. Although the low degree-of-freedom mathematical models of the cranes was suitable for studying the vibration control of gantry crane, a detailed finite element (FE) model of the cranes with a high degree of freedom is still requested to generate a crane model whose static and dynamic stiffness are closer to reality.…”

“…Despite that, the damage indexes, displacement, and drift ratios have not been utilized in the investigation of the seismic behavior of the gantry cranes yet. In the light of the definition of damage indexes in papers [12,23], two new defined damage indexes customized for the gantry cranes are introduced in this research to quantitatively analyze the structural failure mechanism of the gantry crane under seismic waves.…”

Stress analysis of gantry crane cylinder structure

“…It is an important and representative type of intermittent action rail operated lifting machinery with short, repeated, periodic cycle, frequent starting and braking and large impact load. It is widely used in port terminal loading and unloading, shipyards and steel companies [1,2] . As the main metal structure of the portal crane, the four-bar linkage bears the self weight and external load of the equipment, and constitutes the necessary working system and movement space to complete various functions of the crane.…”

Seismic Response of Container Crane under Near-Field and Far-Field Ground Motions

“…The study showed that the near-field ground motions caused more intensive structural response than the far-field ground motions. Peng et al [25] developed fragility curves based on a local displacement ratio and deflection ratio for gantry cranes subjected to near-field ground motions. They evaluated the probability of uplift for the crane according to the earthquake's peak ground acceleration.…”