Study On Damage Identification Method Of Platform Structure Based On Wavelet Transform

As a key equipment for offshore oil exploration and development,the offshore platform has always been under harsh environmental conditions during its long service life,gradually generating and accumulating damages and reducing the safety of platform operations.Therefore,in order to ensure the safe operation of the platform and identify the damage in time,it is particularly important to locate the damaged location and determine the extent of the damage.The real-time health monitoring of the structure has become an important topic that scholars at home and abroad pay close attention to.However,the marine environment is complex and changeable.In reality,the environmental factors are coupled with the damage of the platform structure,making it difficult to effectively identify structural damage.Therefore,corresponding methods should be explored to identify the environmental factors and the structural damage respectively.Under the above background,this paper analyzes and discusses the dynamic response of a certain jacket platform in service by means of numerical simulation based on the signal processing means of wavelet analysis.In this paper,a simple example analysis of the structure response is carried out by wavelet packet transform.The results show that the wavelet packet analysis method is not effective for the identification of environmental factors,but more intuitively reflects the damage status of the structure.On this basis,a step-by-step identification method of environmental conditions and structural damage is established under regular wave conditions,and then the method is revised and verified the applicability under random wave conditions.The analysis results show that the method of spectrum analysis of structure response can be used to identify the wave environment conditions.Meanwhile,the wavelet packet decomposition method of structure response signals can be used to identify the degree of structural damage.Under random wave condition,the spectrum zero-order moment of Fourier transform can effectively identify the wave spectrum parameters.Also,the wavelet packet transform method can effectively identify the degree of structural damage under random wave conditions.