동적 유한요소해석을 이용한 모래시계형 초음파 피로시험편의 응력계산식 보정

Abstract

The stress analysis of an hourglass specimen was performed for the ultrasonic fatigue test (UFT) at resonance frequency around 20 ㎑. Local stresses at the gauge portion of the specimen were calculated using the coventional stress equation with the assumption of an hourglass-shaped gauge portion that had the form of a hyperbolic cosine. For the actual specimen that had a circular arc shape used in the test. Stress distribution through a finite element analysis (FEA) is calculated in comparison to real test results. FEA focuses on the behaviors of local stress concentration occurring in the gauge portion during UFT. The stress concentration effect in the specimen was clarified to compensate for the actual fatigue strength.