Automatic Determination and Evaluation of Residual Stress Calibration Coefficients for Hole-Drilling Strain Gauge Integral Method

作者：Xiao B^*; Li K; Rong Y

来源：Strain, 2011, 47: E525-E534.

DOI：10.1111/j.1475-1305.2009.00650.x

• calibration coefficient
• finite element
• hole-drilling method
• integral method
• residual stress

Residual stress calibration coefficients are used to calculate residual stresses from the measured strains relieved during hole-drilling. The current residual stress measurement practice interpolates the published non-dimensional coefficients for a given measurement condition. Errors are always introduced from the interpolation. In addition, the calibration coefficients vary with respect to factors such as sample geometry dimensions, radius, offset and incline of the drilled hole, and material properties as shown in our sensitivity studies and other researchers' work. This paper presents a better solution that is to calculate the calibration coefficients for each specific measurement. A set of routines coded in Python language for Finite Element software ABAQUS is developed to address our sensitivity studies of these factors. With these automatic routines, a technician who is not familiar with Finite Element and programming can conveniently obtain the calibration coefficients for his measurement conditions and residual stresses automatically. Because coefficients are determined directly by Finite Element Analysis (FEA), dimensionless coefficients are not needed anymore; instead, a modified integral method is proposed and implemented. An experiment is conducted to demonstrate the practical procedures of measuring residual stresses using resistance strain rosette and calibration coefficients obtained with this set of routines. Bending stresses on a narrow and thin beam are measured using this set of routines and compared to the theoretical results and the stress obtained by interpolating non-dimensional coefficients.

• 出版日期2011-6