Study On Methods Of Ultrasonic Testing Aircraft Composite Parts

Due to the physical properties of composite materials,delamination are easily produced in the composite structural components that have been used for a long time.These defects are all threats to aircraft safety.Ultrasonic nondestructive testing is a popular method.It is very significant to guarantee the security of aircraft structural components by using ultrasonic nondestructive testing method.Firstly,the characteristics of ultrasonic transmission are analyzed and the transmission of ultrasonic waves in anisotropic medium is studied in this paper.The software PZFlex is adopted and a finite element model of the probe' sound field is successfully established.Secondly,the numerical simulation of the ultrasonic inspection is implemented under PZFlex in accordance with the constitutive model of composite materials and the characteristics of ultrasonic transmission.Two types of simulation diagram,defect echoes and non-defect echoes,can be achieved.And then,based on the simulation,A-scan pulse reflection method is selected to establish a digital ultrasonic testing system.This system can complete multiple tasks,such as gathering defect echo signals,storing and transmitting them in the system.In the end,the testing system and method that are introduced above are adopted to test defect-free and defective carbon fiber composite materials.Furthermore,the gathered defect echo signals are intensively studied and analyzed.In this article,ultrasonic non-destructive testing technology is selected to test the carbon fiber composite laminates.Delamination,a commonly defect type is the research object.Finite element method is adopted to simulate the testing process.And then simulation images of defect echoes are achieved,which are verifies by experiments.