Characteristic Evaluation on Bolt Stress by Ultrasonic Nondestructive Methods

Abstract EN

Based on the acoustoelasticity theory, a certain relationship exists between ultrasonic velocity and stress.

By combining shear and longitudinal waves, this paper provides a nondestructive method of evaluating axial stress in a tightened bolt.

For measuring the bolt axial stress in different situations, such as under low or high loads, this paper provides guidelines for calculating the stress for a given load factor.

Experimental and calculated results were compared for three bolt test samples: an austenitic stainless steel bolt (A2-70) and low-carbon steel 4.8 and 8.8 bolts.

On average, the experimental results were in good agreement with those obtained through calculations, thus providing a nondestructive method for bolt stress measurements.