Residual stress measurement techniques

Residual stresses exist in most materials and structures. Processes like forging, rolling, extruding, quenching, additive manufacturing, machining, and welding can cause residual stresses to develop. These stresses can influence the way that materials perform (e.g., fatigue, fracture, distortion, and corrosion). There are many different residual stress measurement techniques available to quantify residual stresses. The following are some examples of common measurement techniques. Continue reading Residual stress measurement techniques

Engineered Residual Stress Implementation workshop 2018

Hill Engineering is proud to support the USAF and their objective to advance damage tolerance analysis methods through the Engineered Residual Stress Implementation (ERSI) workshop. At this year’s ERSI meeting, Hill Engineering will meet with other stakeholders in the USAF aircraft community to review progress over the past year towards implementation of engineered residual stress in the USAF fleet. Continue reading Engineered Residual Stress Implementation workshop 2018

BAMF User Workshop 2018

This year’s AFGROW User Workshop will be hosted at the Weber State University Center in Clearfield, UT on September 11-12, 2018. The first annual BAMF workshop will take place at the end of the workshop in the afternoon on September 12th. The BAMF workshop will include presentations on the current work being accomplished by BAMF, recent updates, and a discussion about future plans. If you would like to participate in either the AFGROW or BAMF workshop please register for the meeting at the link above. Continue reading BAMF User Workshop 2018

The first contour method measurement specimen

Hill Engineering’s new facility in Rancho Cordova, CA features a combination of laboratory, research and development, and office space. Our primary conference room is named in honor of Mike Prime, the inventor of the contour method. The Prime Room stands as a tribute to the creativity, insights, and support that Mike Prime has provided to Hill Engineering over the years. One of our favorite pieces on display in the Prime Room is one half of the specimen that was used for the first successful contour method measurement. Continue reading The first contour method measurement specimen

Ring core

At Hill Engineering we work with residual stress on a daily basis. Ring Core is one of the techniques that we use for residual stress measurement. Ring Core is capable of measuring residual stress over depths spanning the near-surface to bulk regions, and can be applied to quantify the average residual stress over the depth of a drilled core. Ring Core is portable, and can be applied under a variety of circumstances, including in the field. Hill Engineering uses Ring Core measurements to support process development and quality control. Ring Core measurements can be performed in our laboratory or at your site, to your specifications. Continue reading Ring core

Hole Drilling Method for Measuring Residual Stresses

We’d like to share with our loyal followers a new book: Hole Drilling Method for Measuring Residual Stresses, written by Gary S. Schajer and Philip S. Whitehead. As you all know, Hole Drilling measures near-surface residual stress. The Hole Drilling method can be applied to quantify the average residual stress over the depth of a drilled hole (typically 1.0 mm depth). It can also be applied to determine the distribution of residual stress versus depth from the surface to a depth of half the hole diameter. Hole Drilling is portable and is a common method for residual stress measurement that can be applied under a variety of circumstances, including in the field. Continue reading Hole Drilling Method for Measuring Residual Stresses

Thermal Processing in Motion 2018 – recap

Hill Engineering recently attended the 2018 Thermal Processing in Motion Conference in Spartanburg, South Carolina. This conference brings together international experts from around the globe to present the latest innovations and research in thermal processing including: additive manufacturing; phase transformations; microstructure/property relationships; quenching and quenchants; thermomechanical thermal processing; and surface hardening. The second day of the conference included a Residual Stress Workshop. Continue reading Thermal Processing in Motion 2018 – recap

Thermal Processing in Motion 2018

Hill Engineering is delivering a keynote address titled Overview of Residual Stress Measurement in Industry Applications at the upcoming 2018 Thermal Processing in Motion Conference in Spartanburg, South Carolina. The mission of this conference is to bring together international experts from around the globe to present the latest innovations and research in thermal processing including: additive manufacturing; phase transformations; microstructure/property relationships; quenching and quenchants; thermomechanical thermal processing; and surface hardening. Hill Engineering’s presentation will include a summary of recent work related to residual stress measurement in support of production quality control. Continue reading Thermal Processing in Motion 2018

AeroMat 2018: Residual stress production quality control

Hill Engineering is presenting about residual stress production quality control at the upcoming 2018 AeroMat Conference in Orlando, FL. The AeroMat Conference focuses on innovative aerospace materials, fabrication and manufacturing methods that improve performance, durability and sustainability of aerospace structures and engines with reduced life-cycle costs. Hill Engineering’s presentation will include an overview of ongoing work related to quality control processes for residual stress in manufacturing. The abstract text is presented below. Continue reading AeroMat 2018: Residual stress production quality control

Aircraft Airworthiness & Sustainment 2018

Hill Engineering is presenting about residual stress evaluation in legacy aircraft cold expanded fastener holes at the upcoming 2018 Aircraft Airworthiness & Sustainment Conference (AA&S) in Jacksonville, FL. The mission of this conference is to identify the challenges and the collaborative work being done within the aerospace community in improving the safety, airworthiness, availability and cost effectiveness of both our military and commercial aircraft fleets. Hill Engineering’s presentation will include a summary of recent work in airframe structures, demonstrating the effect of aircraft service on the residual stress at cold expanded fastener holes. The abstract text is presented below. Continue reading Aircraft Airworthiness & Sustainment 2018