Before well-known carbon fiber modulus of elasticity determines method, it is the instrument of use high accuracy, tension of record carbon fiber and be out of shape process, draw becomes curvilinear table, be out of shape by tensional — formulary, computation gives modulus of elasticity, make complex, take time, beautiful money so much, cannot undertake an analysis to the fiber structure of flabby process additionally.
Russia experiment uses ultrasonic method to determine carbon fiber (silk bundle) modulus of elasticity, it is to determine the physics of fiber itself is numeric, namely of wave of the flexibility on fiber pass time. The principle is to use ultrasonic emitter, without the contact from fibrous one aspect of the matter the ground gives out ultrasonic, by fiber the ultrasonic of another end accepts sensor to receive signal, measure sound wave of calm favorable balance of trade to come in emitter the time that passes between receiver, computative industry pattern:
The distance of emitter and receiver
× of density of fiber of ＝ of modulus of elasticity (————————————)2
Ultrasonic base line passes time
Determined with this kind of method 3 kinds of polyacrylonitrile base carbon fiber silk bundle, without the contact, without injury, determine what need silk bundle the smallest length is 5cm, far under other determine method. Determine result and silk bundle puissant numerical value and drawing numerical value do not have immediate impact. This kind of method can determine already initiative carbon fiber silk bundle modulus of elasticity, can determine again the silk in composite material bundle modulus of elasticity, can determine secondhand tiny bit bundle of stretch function when motion, also can determine the modulus of elasticity that makes a local structure of bundle of product go up.
