Assessment On Structural Vibration Induced By Mechanical Equipment On Offshore Production Platforms

In the process of production,more attentions have been taken on the vibration of platform which caused by the operation of large machinery and equipment.The study analyzes and evaluates the vibration of topside equipment on the offshore production platform based on the project of a platform vibration analysis of Engineering Corp.We finally make a significant contribution in many aspects which include the dynamics analysis of mechanical equipment,the fatigue life-span assessment of the structure,the personnel comfort evaluation and the study of equipment vibration isolation plan.The contributions mentioned above provide technical support for the analysis and evaluation of equipment vibration on the production platform,and are also applied to practical project.The main research progress and achievements are shown as belows:(1)The vibration mechanism of topside equipment is studied on the offshore production platform.The finite element software ANSYS is used for parametric modeling of topside structure and large mechanical equipment with consideration of the comparison between model centroid and weight.(2)The intrinsic property of global and local topside structure is studied combined with the local structure mode analysis method on the offshore production platform.Additionally,the inherent frequency reserve of local structure is evaluated according to the related standard.In the process of dynamic analysis,with consideration of equipment load excitation,the classification of working condition,measuring point and other necessary factors in the dynamic response analysis,we conduct the harmonic response analysis and transient response analysis on the targeted topside structure.Then,based on the related vibration evaluation rules on domestic and overseas,the results of vibration analysis are preliminary evaluated.(3)The process of vibration fatigue analysis of topside structure is determined on the offshore production platform.According to the rain-flow counting method and linear cumulative damage principle,the MATLAB software is employed to develop fatigue life calculation program,and the fatigue damage of topside structure key nodes and its corresponding fatigue life-span are calculated under different conditions.Simultaneously,based on the evaluation rules of equipment vibration comfort,the evaluation steps of topside structure comfort are determined and then the above steps are used to evaluate the personnel comfort on the offshore production platform.(4)The control plan of structure vibration is proposed based on the dynamic analysis results of topside structure under the condition of load excitation.And the vibration isolation measures are used for large mechanical processing.Then,the vibration effect of topside structure is discussed under different vibration isolation plans.As a result,the optimal plan is obtained.Finally,we re-analyze the dynamic response of topside structure which has taken vibration isolation measures and evaluate the calculated results.Based on the study of vibration analysis and the assessment of mechanical equipment on the offshore production platform,the methods provides an idea about the practical engineering problem,and are helpful to solve the equipment vibration problem of offshore platform.