Please send me an Email if you are going to use this package. Also, you are welcome to participate in the Shock & Vibration courses. Thank you,Tom IrvineEmail: tom@irvinemail.org * * * License information: The software packages on the following links are freely placed in… Read more
A question that comes up whenever a laboratory is planning its first large electrodynamic shaker installation: the specification and the quotations keep referring to a seismic mass, or a reaction mass, or an inertia block. Is that a real, physically heavy object that has to… Read more
A question that comes up whenever a laboratory is planning its first large electrodynamic shaker installation: the specification and the quotations keep referring to a seismic mass, or a reaction mass, or an inertia block. Is that a real, physically heavy object that has to… Read more
The Problem Here is a problem that comes up more often than the standards would suggest. An engineer is deriving a random vibration maximum predicted environment (MPE) for launch vehicle components mounted very close to the engines. Accelerometer data from engine test stand and stack… Read more
Does Compression Grow Cracks? — Vibrationdata Vibrationdata Fracture & Fatigue Stress intensity conventions At a stress ratio of R = −1, the choice between full-range and clipped ΔK is worth a factor of 2n in life. It is usually the largest single lever in a… Read more
A recurring question in Central and Eastern North America (CENA) seismic qualification goes something like this: the site-specific ground motion exceeds the IEEE 693 required response spectrum above 10 Hz, sometimes by a factor of two to four. Does that mean the equipment is unqualified?… Read more
Composite Materials in Turbofan Jet Engines | Structural Dynamics & Mechanics Vibrationdata · Structural Dynamics & Material Physics Composite Materials in Turbofan Jet Engines Aeromechanics, Centrifugal Mechanics, Impact Damage Tolerance, and Aeroelastic Tuning Introduction The modern high-bypass turbofan represents one of the most demanding optimization… Read more
A Shell station on a Huntsville, Alabama arterial. Four slender columns, a flat deck roughly 60 feet by 30 feet, fifteen feet of clearance, and a fascia band carrying the brand colors. It is one of the most repeated structural forms in North America, and… Read more
A change to a single equation in ASME B31.3 has meaningful consequences for how piping displacement stress is evaluated in high-cycle service. The change is small in appearance and large in effect, and it is worth understanding both the arithmetic and the seventy years of… Read more
Skyscraper design was once governed almost entirely by strength — could the frame carry gravity, wind and seismic loads with adequate margin? For the new generation of ultra-slender “pencil towers,” the governing requirement has shifted to something more subtle: occupant comfort. A building can be… Read more
Image credit: Merchant Navy Decoded — Propeller of Ship Walk along any harbor dry dock and you will notice that ship propellers almost always have between three and six blades, with four and five being the most common for merchant vessels. The blade count is… Read more