admin Figure 1. Boeing 787 Aircraft Carbon fiber/epoxy laminates are widely used in aeronautic and aerospace structural components mainly because of their excellent specific mechanical properties. These laminates show mechanical properties similar or higher than the conventional metallic materials in terms of strength-to-weight and stiffness-to-weight ratios. The… Read more
Rolls Royce Engine Blade-off Test Video Link 1 Video Link 2 The engine blade-off test is performed to make sure that the engine can survive a fan. compressor or turbine blade breaking off within the engine, without fragments being ejected through the outside… Read more
The Lomb-Scargle Periodogram is a least-square method which is useful for calculating the Fourier transform of a time history with gaps or an uneven sampling rate. Reference Paper This function has been added to the vibrationdata GUI package Python script & Utility: lomb_scargle.py tompy.py -… Read more
Aircraft and launch vehicles behave as unconstrained systems in flight, with six rigid-body modes. These vehicles may be “trimmed” using aerodynamic control surfaces and thrust vector control to prevent rotation about the vehicle center-of-gravity (CG). There is a need to calculate the vehicle’s displacement response… Read more
This is a work-in-progress… The fatigue units are available to students who enroll in the Shock & Vibration course series. __________________________________________________________________ M.H.A. Bonte, A. de Boer, R. Liebregts, Prediction of mechanical fatigue caused by multiple random excitations: stress_psd_1.pdf Dr.-Ing. Marinus Luegmair, Dr.-Ing. Alexander Ziehl, Von Mises… Read more
The top figure is the time history from the El Centro earthquake, North-South horizontal component. The middle is the corresponding Waterfall SRS with 4 second segments and with 50% overlap. The bottom is the spectrogram. The Waterfall SRS is calculated by first taking the complete… Read more
Another work-in-progress… Step 1: Download a video file. Step 2: Play using VLC media player. * * * * * Launch Vehicles Delta 4 Heavy Launch Vehicle Shock Events Pegasus Launch Vehicle Linear Shaped Charge Test * * * * * Helicopters Chinook Ground Resonance… Read more
I am trying to collect all my presentations. This is a work-in-progress… Thank you, Tom Irvine * * * * * * NAFEMS World Congress 2017 Introduction to Vibration Spectral Functions Random Vibration Vibration Fatigue Shock 1 & 2 Videos * * * * *… Read more
Certain equipment must be designed and tested to withstand vibration. This is common in the automotive, aerospace, military and other industries. The equipment is typically mounted to a shaker table and then subjected to a base input random or sine sweep vibration test. The random… Read more
LA Times Article, Supersonic passenger jets might make a comeback, more than a decade after the last Concorde flight link Boom Technology Inc. – Tom Irvine