The Research Of Ultrasonic Testing In The RTM/textile Composites

It can get the components of low cost,high performance and complexstructure,through combining the weaving techniques,with RTM.so it has been widelyused in air space, the manufacturing of automobiles and sports equipment.But it iseasy to generate many defects in the RTM process,like fold,dry spot,the pore,etc.theperformance of the component is influenced by the existence of thedefects.however,RTM/textile composites is anisotropicthe in the physical performance,so it is difficult to defects detection and evaluation.This paper studies the theory of linear ultrasonic and nonlinear ultrasonic detection,and firstly detects the macro-defects and micro-defects in the RTM/textile composites,by linear and nonlinear ultrasound method. The research object of the paper is carbonfiber composite materials with fiber cloth layer,and RTM injection molding,it getthree kinds of sample by using different injection velocity,and one kind of samplewith artificial macro-defect,And fiber stitching,RTM molding composite materials.First of all,it studies the transmission characteristics of the wave in the RTM/textilecomposites,theoretically analysis of higher harmonic sourcers,and researches theequation and solution of the nonlinear wave.The relationship between charaterisiticsparameters and testing objects is established,the detecting method and testing systemis selected.Secondly, it designs the test block used in the experiment.It designs themould,According to the characteristics of RTM process,and the existing experimentcondition, and moulding the test block that meet the requirement of the research.Finally,.it detect the macro-defect and micro-defect in the RTM/textilecomposites,using linear and nonlinear ultrasonic.The experimental results show that the two methods can be used for detecting thedefects in the RTM/textile composites.For the macro-defect,two method can detecteffectively,and linear ultrasonic system is simple,and low cost.For the micro-defect,nonlinear ultrasonic testing technology is more sensitive, a higher precision to defects.