Research On Wind Loads And FSI Characteristics Of Wind-Induced-Vibraton For Container Cranes

Thanks to the lightweight development of quayside container crane(hereinafter referred to as "quayside bridge"),the existing materials can be fully utilized,but it also makes the structures of the quayside bridge becoming longer,thinner and much more flexible,which leads to the aggravation of fluid structure coupling effect and the increasing sensitivity of structure to wind loads.Nowadays,wind loads are still being determined according to GB/T3811-2008 The Code for Crane Design(hereinafter referred to as the code),whose static equivalent treatment of wind loads may easily cause the redundancy of the strength of the crane.Moreover,it can’t provide the fluidsolid-interaction(FSI)characteristics of the crane’s structures.Thus the code can no longer meet the current demands of lightweight design.It would help a lot if the wind field and wind-induced-vibration characteristics are obtained when carry out the research of the wind resistant design of crane.So some works have taken wind tunnel tests as an assistant,but it cost too much time as well as fortune,and that’s why wind tunnel tests haven’t been widely used in this field.Luckily,the numerical wind tunnel can simulate the windward and wind-induced-vibration characteristics of the crane under the working wind environments economically and efficiently.Therefore,the primary problems for the anti-wind design of crane are to explore a reasonable and accurate enough numerical simulation approach,and study the wind-induced-vibration characteristics of the structure.A certain type of quayside bridge designed by ZPMC is taken as the main object of this dissertation.The wind tunnel test and numerical simulation are adopted to analyze the windward characteristics of the quay bridge successively.Since the reliability of the numerical simulation method of wind field in this paper is verified,the research on the combined wind resistance effect of quay bridges is carried out.Then the wet modal analysis method of FSI is adopted to explore the wet modal characteristics,modal characteristics under the fluid-solid-interaction effect,of the bridge and its components.And the wind-induced vibration response characteristics of the crane components under different slenderness ratios are studied.The specific research content is as follows:(1)Combined with the wind tunnel test and the numerical simulation of wind field,the rationality of the wind field simulation approach in this paper is verified,and the research on the wind resistance effect of the combination of two cranes is carried out.The research discusses the impacts of two,the wind angles and the distances between the quay bridges,on the united anti-wind effect of two cranes.And a dimensionless parameter which may represent the effective range of the effect is proposed;(2)The wet modal analysis is carried out for the whole crane and its components whose slenderness ratios are high,then the vibration frequencies and modes of the crane as well as its components are studied under the influence of FSI.The influence of slenderness ratios of the components on the wet mode is studied;(3)Through fluid structure coupling analysis method,the vortex induced vibration response of the common large slenderness ratio components on the quayside bridge is studied.And the study obtains the stat-up displacement traiectory and vibration frequency response of the vortex induced vibration of the diagonal brace.The two-direction FSI analyses are carried out for different sections of the components,then the slenderness ratios that are prone to vortex induced resonance are given,which provides a supplement and reference for the design of the quay bridge.