Tag: Residual Stress Measurement

Search results for Hill Engineering blog posts containing the tag residual stress measurement

Publication alert – Multiscale framework for prediction of residual stress in additively manufactured functionally graded material

by Adrian DeWald

Hill Engineering recently published new research with collaborators from around the world including South Korea, Australia, China, and the United Kingdom. The work is titled Multiscale framework for prediction of residual stress in additively manufactured functionally graded material. The abstract text is available here along with a link to the publication.

Continue reading Publication alert – Multiscale framework for prediction of residual stress in additively manufactured functionally graded material

Hill Engineering’s DART issued second US patent!

by Robert Pires

Hill Engineering has been recently issued its second US patent for the DART™ measurement system. This updated device offers improved residual stress measurements within small-diameter pipe applications, allowing for more accurate analysis in both in-laboratory and non-laboratory settings.

Continue reading Hill Engineering’s DART issued second US patent!

TrueSlot® – near surface residual stress measurement

TrueSlot® is an innovative technique for measuring near-surface residual stress that is more reliable than conventional techniques.

TrueSlot® is a residual stress measurement technique for generating a profile of residual stress versus depth from the material surface. The stress computation is similar to slitting but offers more sensitivity near the surface due to the proximity of the strain gage.

Additionally, TrueSlot® is globally less invasive than slitting because the volume of removed material is localized to the surface and does not typically extend through most of the specimen thickness.

A solid model block with a long but thin slot cut out of the top.
A model of a completed TrueSlot® method measurement.

The physical application of TrueSlot® is like hole drilling, however instead of a shallow hole being milled into the body of a specimen containing residual stress, the material removed is a shallow slot. The strain released with each incremental slot depth is measured near the slot using a strain gage.

TrueSlot® is useful for

  • Production quality control applications
  • Applications requiring in-field measurements with portable equipment
  • Near-surface residual stress determination
  • Parts with large or complex geometry
  • Applications with challenging measurement access
  • Applications requiring rapid turn time

TrueSlot® was found to have better repeatability when compared with conventional x-ray diffraction.

A plot with depth and repeatability as the axis and two lines of data, one red, the other black. For most depths, the red line is higher than the black, signifying that XRD is less repeatable than slotting.
Results from the method repeatability study which found TrueSlot® to be a more repeatable measurement method than XRD

You can read about our repeatability study here.

TrueSlot® measurements are performed using our DARTTM system for automated residual stress measurement.

The Big 200! – Celebrating a milestone blog post

by Robert Pires
An orange and blue banner with a large 200 printed on it.

Gather round readers!

We are very excited today because in this blog we cross an incredible milestone: our 200th post! That’s right. Since the inception of the Hill Engineering blog back in March 2016, we have published 200 times.

Let’s take a look back over the past 7 years of blogging bliss!

Continue reading The Big 200! – Celebrating a milestone blog post

Strain Gaging Services

Strain gages are devices used to measure strain on the surface of an object. These strain measurements can be used to infer the amount of stress induced on the object, as is done with many types of residual stress measurements.

Additionally, strain gages can be used to measure things such as aircraft wing deflection, bridge cable creep, and tensile testing for material properties, making them an ideal tool for in-field measurements.

Strain gages come in many shapes and sizes and can measure strain in a single direction or in multiple directions, depending on the goal of the experiment. Strain gages can be used on a wide variety of materials under many conditions, such as in extreme temperatures or underwater.

Hill Engineering has extensive experience with strain gage application and can help design the experiment needed to reach your project’s goals. Strain gage application can be performed in our laboratory or at your site, to your specifications.

Strain gage application is useful for:

  • Applications requiring in-field measurements with portable equipment
  • Measuring strain in multiple directions
  • Parts in every shape and size – nothing is too big or too small
  • Measuring residual stress

If you’re interested in how we apply a strain gage to a simple specimen, watch our video:

Photograph of a uniaxial strain gage
Photograph of a uniaxial strain gage

Zoomed in image of a uniaxial strain gage grid
Zoomed in image of a uniaxial strain gage grid

A photograph of a pile of various strain gages
A photograph of a pile of various strain gages