Multi-Component Residual Stress Profiling in Thick Sections
Deep Hole drilling is used to measure bulk residual stress in thick sections. The method can be applied to generate a residual stress profile through the thickness of large parts. Deep Hole drilling is typically performed in the laboratory, but can be applied in the field.
Deep-Hole Drilling is based on the principle that residual stress causes a body to deform when it is cut, and drilling a hole into a body while measuring its deformation before and after the release of residual stress allows calculation of the initial (pre-cut) residual stress distribution.
Deep-Hole Drilling is realized by drilling a reference hole through the component and accurately measuring its diameter before and after residual stress release by trepanning coaxially around it. The measured deformation of the reference hole (before and after residual stress release) enables the original residual stresses to be calculated using elasticity.
Deep Hole Drilling is Useful For
- Measuring a profile of the bulk residual stress in thick sections
- Applications requiring in-field measurements with portable equipment
- Measuring multiple stress components (in-plane principal stresses)
- Parts with large or complex geometry
External Materials
Illustration of the deep hole method for residuals tress measurement showing the initial hole and trepanned core.
Line plot of residual stress versus position through the thickness of a plastically bent beam.