Deep hole drilling (DHD) is a mechanical method used to determine residual stress as a function of depth. DHD is capable of measuring the residual stresses deep into a part, beyond the capabilities of typical hole drilling. The technique can be used to determine the principal residual stresses several inches into the thickness of a part. DHD consists of drilling a reference hole into a part. The diameter of the hole is then measured at various angular and depth positions using an air-gage system. The reference hole is removed from the part via ring coring, thereby relieving the residual stresses in the vicinity. Residual stress relaxation will cause the diameter of the reference hole to change. The reference hole diameter is then measured again at the same positions as done prior to ring coring. The change in diameter and height is used to calculate the residual stresses throughout the depth of the reference hole.
The Deep Hole Drilling Method
- Determination of residual stress up to several inches into the part
- Measurements can be made in metallic and non-metallic components
To discuss your residual stress measurement needs, fill out the form on our RFQ page or give us a call at (800) 883-0851.