Welcome George Kaschner

We would like to welcome George Kaschner to Hill Engineering. George comes to Hill Engineering with more than 30 years of experience, most recently from Los Alamos National Laboratory. George has degrees in Applied Physics and Materials Science & Engineering, and received his Ph.D. from UC Davis in 1997. Since then, he has accumulated significant experience in materials science, materials testing, and data analysis. Continue reading Welcome George Kaschner

ASIP conference 2018

Hill Engineering is presenting at the upcoming 2018 United States Air Force Structural Integrity Program Conference (ASIP) in Phoenix, AZ. Our talk will focus on residual stress evaluation in legacy aircraft cold expanded fastener holes. The 2018 ASIP Conference is specifically designed to bring together the world leaders in the area of aircraft structural integrity, to disseminate information on state-of-the-art technologies for aircraft structures in both the military and civilian 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 ASIP conference 2018

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