This thesis provides a new method to measure the opening loading of fatigue crack That using ultrasonic testing detects echo of crack tip is similar result to general method for use strain gage.

• 本文也提供了另一量测开口荷重的方法，利用超音波检测技术，将它应用于疲劳裂缝开口荷重的量测，从量测的结果可发现荷重与裂缝尖端的回波变化与一般量测开口荷重的方法有相似的结果。