Hill Engineering, LLC

Fatigue engineering is subject to uncertainty, and data from well executed tests are used to validate conclusions made by analysis and to provide a basis for structural certification. Our staff have extensive experience in testing materials and components under slowly varying, static loads, and under rapidly varying cyclic loads. Tests under static loads are used to assess material properties or to assess the load-deformation behavior of structural components. Tests under cyclic loads provide time to crack initiation, time to failure, or measurements of crack growth over time. We have extensive experience in measuring fatigue crack growth behavior in metallic materials. Past programs have measured crack growth with microscopy and photogrammetry at the surface, cracked area with direct current potential drop, and through-thickness crack profiles with quantitative fractography. By assessing crack growth with a variety of experimental methods, we enable robust analysis validation for cases of complex cracking. Our capabilities in fatigue engineering allow for careful design of a fatigue test program. Whether the tests use constant amplitude loading or an irregular loading spectrum, we specialize in engineering the test that meet your needs. Much of our experience is in non-standard test programs, which require engineering to optimize the test setup. Few others match our capability and experience in fatigue test engineering.

Hill Engineering's expertise in residual stress and material performance provides us with a unique opportunity to effectively design and manage production quality programs. For example, a quality system for residual stress in aluminum forgings would provide the means to control, monitor, and certify the residual stress. In general, the quality system seeks to identify key metrics in the manufacturing process, establish a testing protocol for these metrics to qualify the manufacturing process, and then perform either lot-release and/or surveillance testing to demonstrate process stability over time. Process simulation may be used to identify locations for quality control measurements and portable measurement technology like hole drilling may be used to perform quality control measurements inside of a manufacturing facility.