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

Visiting the Utah office

Last year, Hill Engineering opened a satellite office in Layton, UT with the goal of better connecting with our customers and partners in the local area. Mike and I recently made a trip out to the office to check in and to spend some time working with our excellent team there to better understand and appreciate their outstanding work. Continue reading Visiting the Utah office

Residual stress definition

Residual stress definition – residual stress is defined as the stress that is present in a material in the absence of externally applied loading. Residual stresses often form during manufacturing and are typically an unintentional byproduct of a manufacturing process. As engineers we care about residual stresses because they affect material performance. Continue reading Residual stress definition

Fatigue tests

Fatigue tests are an important part of our work at Hill Engineering. There are many reasons to perform fatigue tests including: 1) qualifying the performance of parts for production, 2) ranking and optimizing different production processes, 3) validating fatigue analysis results and associated models, 4) understanding the performance of parts already in service, and more. The following discussion covers some basic details of typical fatigue tests. Continue reading Fatigue tests