Evaluating Effectiveness of VSR

Vibratory Stress Relief (VSR) is a technique that uses vibration equipment to excite a part at a resonant frequency, which reduces the working residual stresses in the part and enhances service life. Le Quy Don Technical University has a project to evaluate the effectiveness of VSR. Measuring the before and after residual stresses is one of the challenges to demonstrating this effectiveness.


The hole drilling method is a well-established technique for determining residual stress magnitude, and is the subject of an ASTM standard (ASTM E837). This is a semi-destructive technique that requires a small hole to be drilled into the part to locally relieve residual strains. These strains are sensed by specially designed strain gages bonded around the hole.


Dr. Nguyen Van Duong, Bui Manh Cuing, and Nguyen Dihn Chien from the Le Quy Don Technical University used an RS-200 residual stress measuring system and strain gages from Micro-Measurements for their evaluation. The residual stress in various work pieces – such as large gears, shafts, and machine foundations – was measured to quantify the effectiveness of relieving these stresses using Vibratory Stress Relief equipment.


The measured strains are then used in standard equations to compute the residual stresses. The team found that the Micro-Measurements RS-200 drilling system combined with special Micro-Measurements strain gages designed specifically for the task of measuring relieved strains are efficient, accurate tools to acquire necessary data.


Read the full Case Study

See the RS-200 video

yhernik's picture

Yuval Hernik

StrainBlog Editor in Chief