The NDT Techniques Of Rope Bridge Anchorage System Based On Magnetostrictive Guided Wave

The Rope Bridge has become an important bridge across the river and sea for its advantages of strong spanning ability and beautiful structure.As important stress component of the rope bridge,anchoring system’s security directly affects that of the whole bridge.Problems in construction technology,environmental corrosion and maintenance greatly threaten safety of anchoring system and bring the long-span rope bridge security risk.However,rope system and its anchoring system are wrapped by protective materials or embedded in the main girder,therefore in daily tests and maintenance,direct observation into the inner defects is not available.How to test the anchoring system in nondestructive,rapid and accurate way has become outstanding problem in maintenance and management of the cable bridge.Therefore,based on the structure characteristics of rope bridge’s anchoring system,according to the current research of anchoring system detection technology,this article proposes detection technology based on magnetostrictive guided wave,which can ensure nondestructive,rapid and accurate detection of the bridge.Firstly,combing existing documents and field survey results,this paper summarizes common diseases of Rope Bridge anchoring system,and further studies mechanism of those diseases,coming to a conclusion that it’s mainly caused by chemical corrosion and physical causes.Secondly,based on summary of anchoring system diseases and analysis of its mechanism,this paper analyses cause and influential factors of magnetic property of the anchoring system,and further studies mechanism of diseases evolves the megetic property.Thirdly,combined with the fact that magnetic property evolution is related to the diseases,the paper analyzes the magnetostrictive guided wave nondestructive testing principle and application scope,and confirms the use of magnetostrictive guided wave in testing anchoring system.Based on this,the paper establishes the magnetostrictive guided wave nondestructive testing system by hardware and software design of the system,and brings forth key technology of magnetostrictive guided wave detection.Finally,the parallel wire pull sling simulation test verifies it feasible for magnetostrictive guided wave to detect anchoraging system internal defect parameters and defect location and it testifies the feasibility and reliability of the design via crude steel rope broken test.According to safety problem related to Rope Bridge,this paper puts forward nondestructive testing technology of achongring system based on magnetostrictive guided wave,and verifies its feasibility and reliability via two tests.Therefore,this research result can be greatly applied in test of Rope Bridge.