Modeling the Beam Deflection of a Gantry Crane under Load

Abstract

Gantry cranes load and unload containers from container ships. To ensure safety and operation, the deflection of their main beams under load should be analyzed. This deflection depends on the weight of the loaded container as well as on the position of the trolley that moves the container. For this study, a bivariate polynomial model is built to estimate the deflection based on these two inputs. This two-dimensional load-dependent model is developed in four steps in order to determine the shape of the deflection (dependent on the trolley position) as well as its magnitude (dependent on the container weight). A specific gantry crane was monitored with several sensors where five are inclinometer sensors that observe the tilt along the crane’s main beam and two are tacheometers that observe the trolley position and the absolute deflection. By collecting data from 18 loading operations, the parameters of the deflection model are estimated. Based on this data, the deflection under load is processed dependent on the container weight and trolley position. The verification of the entire model shows deviations within