Study Of Acoustic Source Localization Methods Based On New Triangulation Technique In Two-dimensional Plate

The material damage of the structure is common.And the damage in many cases can reduce the performance of the equipments and even bring safe hidden trouble.Sound source localization is one of the purpose of the acoustic emission technology.In the early stage,damage can be found by acoustic source localization to prevent or reduce such accidents.Two-dimensional plate structures have a wide range of applications in the automobile body,liquid storage tank,aviation equipment,pressure vessels and other kinds of structures.But in recent years some new engineering materials such as the fiber reinforced composite solid materials are extensively used.The traditional triangulation time difference technique can not realize acoustic source location in the two-dimensional anisotropic plate structures.People are short of the cognition for acoustic emission source localization in anisotropic plates.This paper reviewed the development of acoustic emission of the two-dimensional plate structures from the perspective of the acoustic emission theory,the wave propagation characteristics,signal processing and instrument system,research work of acoustic source location methods,emphatically resolving the principle and implementationtechnology of new triangulation time difference technique.A new four sensors positioning method forming like "z" is presented which based on the new triangulation time difference technique.The new method is not limited by the anisotropy of structures.Don't need to know the plate velocity distribution.The new suggestion can locate fast,simple and easy with less sensors.At the same time it reduces the positioning area.A feasible technology is provided on project organization for launch positioning method.At the same time,the validation process of experiments in the laboratory is improved.Acoustic emission source location experiment was realized by the single channel pulse signal launch receiving apparatus,oscilloscope and two ultrasonic sensors.At present,most of the laboratories in university physics experiments use square method,the arbitrary planar triangle algorithm and other sound source localization methods.These methods require two-dimensional plate be isotropic and need to know in advance the information such as the wave velocity in the plate.The experiments usually seem pencil break as acoustic emission source.Receive acoustic wave with at least four receiving sensors and one multi-channel acquisition equipment to complete the experiment.The experimental cost is higher.Complex calculation process needs professional computing software which is not suitable for popularization and in-depth understanding of physical issues.These problems seriously restrict the acoustic emission technology tohave an in-depth application in structures damage location.The experimental results show that new triangulation time difference technique can be accurate pinpoint the location of sound source.And the new four sensors positioning method forming like "z" can quickly pinpoint the location of sound source and only need a smaller detection area.For nondestructive testing of industrial fields such as acoustic emission location technology,contribute a more widely applied acoustic emission source localization method without being limited by the anisotropy.New method can quickly locate acoustic emission for two-dimensional structures with less ultrasonic sensors.