Influence of Ultrasonic Vibration Frequency on Acceleration of Hydrothermal Aging of FRP

Abstract

This study deals with the accelerated hydrothermal aging test method of fiber-reinforced plastic panels by applying an ultrasonic vibration to the material. The ultrasonic vibration was applied to the specimen during or after immersion in water. The accelerated aging tests were conducted at three vibration frequencies (50 k Hz, 100 k Hz, and 200 k Hz), and the effect of the ultrasonic vibration frequency on the acceleration of aging was discussed. The effect of applying the ultrasonic vibration for the accelerated aging was evaluated from weight change measurements and the bending property. The aging was accelerated by applying the ultrasonic vibration continuously during the water immersion, and it was found that the most effective frequency of ultrasonic vibration was 50 k Hz. The ultrasonic vibration affected the acceleration of the dissolution from the interface, and as a result, the weight loss occurred at shorter immersion time compared with the ordinary immersion test. Such dissolution from the interface induced the weight gain due to the water penetration and the bending strength reduction.