New Glenn Failure, May 28, 2026

Tough day for Blue Origin’s New Glenn. Blue Origin was performing a static fire (hotfire) test ahead of an anticipated fourth launch — the rocket was likely fully fueled, contributing to what is described as one of the largest rocket explosions in U.S. history. Blue Origin,… Read more

Shock, Vibration, Fatigue & Machinery Classes Beginning September 2026

This September 2026 course series provides practical training in shock, vibration, fatigue, structural dynamics, FEA, machinery vibration, acoustics, and rotor dynamics for engineers working with test data, qualification requirements, failure analysis, and mechanical system reliability. Each one-hour class is organized in a semester-style format, with… Read more

Effective Modal Mass and Modal Participation Factors

ModalMass_revK.pdf Effective modal mass and modal participation factors provide a quantitative basis for identifying dynamically significant vibration modes and for guiding modal truncation in structural dynamic analyses. This paper presents a unified formulation for both base-excited systems and grounded systems subjected to externally applied forces.… Read more

Fatigue Cracks in Anodized Coatings

Image reference: https://onlinelibrary.wiley.com/doi/full/10.1002/adem.202300394 What Is Anodizing? Anodizing is widely used to improve corrosion resistance and surface durability in aluminum and other light metals. However, under cyclic loading, anodized coatings can play a surprising, and sometimes detrimental, role in fatigue performance. This post walks through why… Read more

Tom & Friends’ ebooks

An Introduction to Shock & Vibration Response Spectra Revision H eBook Shock & Vibration Stress & Strain as a Function of Velocity, Revision Q, eBook link Launch Vehicle POGO, Combustion Instability & Thrust Oscillation: Dynamics, Instabilities, and Mitigation Techniques link Airport, Traffic & Community Noise… Read more

Equipment Racks & Earthquakes

Seismic-restrained Isolators The following is an edited response from ChatGPT. Resonant response of the equipment rack circuit boards should not be an issue, because circuit board fundamental frequencies are typically above 200 Hz, whereas seismic energy is mostly below 20 Hz. But electronic components may… Read more