The Application Of Modal Analysis In Damage Detection Of Pipeline

Due to affection of many kinds of facts,it is inevitable to meet damages in manufacturing and using of structures,parts and equipments.The main damage types of structure comprise of quality of materials,welding quality,external influences,corrosion,and so on.The damages make a security risk and cause accidents easily,endangering the lives of the people and lead to the loss of property.Therefore,it is significant to do damage detection,early warning and real-time monitoring to the structures.Based on the experiments,using a combination of theoretical and experimental methods to deal with the vibration works,Modal analysis has reached an advanced level.The application of modal analysis method makes it possible to simplify the structure to get the system response. As an important way to solve vibration problems in projects,it is applied widely in many engineering fields.As performed by partial loss of stiffness generally,the structure damage leads to structural dynamic characteristics change.The modal data can be got through modal analysis method for dynamic design and damage detection.The application of modal analysis method could inspect the structure quickly and it becomes a new research orientation in pipeline testing.Since the test objects and methods are different,not all of the parameters can detect the damages effectively in any case.So it is necessary to choose the right indicator in different cases.After the comprehension of the non-detective testing methods,this paper selects the modal analysis method by the appropriately indicators to complete the pipeline damage identification.This paper introduces the indicator Change of Modal Strain Energy and the indicator Change Rate of Modal Curvature to detect damages in the pipeline,deduces the relevant formulations,and simulates the detection in many different situations.The results show that these indicators could detect the damages effectively both in single and multiply cases,they can reflect the damage degree as well.Followed the methods above,an experiment is finished to verify the validity of the indicators.This paper also studies the principles of the Operational Deflection Shapes and its parameter identification,and prospects its usage in damage detection of the pipeline networks.