Modal test data processing methods perform curve-fitting on measured frequency response functions. These are indirect methods for extracting natural frequencies and damping ratios. The FRF methods also yield mode shapes which may be complex if the system has non-proportional damping. Each complex mode shape can… Read more
Tapiola Lutheran Church in Espoo, Finland, Opened in 1965 Helmholtz-type resonators are built into the walls of the church. The slots between brick pairs and cavities behind them act as both absorbers and diffusors of sound. The absorption reduces the reverberation time as desired for… Read more
PV = pseudo velocity The following method is intended for components which are to be tested to power spectral density (PSD) specifications on shaker tables. The method can be applied to sine-on-random specifications as well. The purpose of this document is to recommend velocity severity… Read more
Liquid fuel rocket engines undergo hot fire testing before flight in order to verify their performance, design integrity, etc. The engines are mounted to heavy-duty, immovable stands for this purpose. These tests are also referred to as static fire tests. Furthermore, the tests are almost… Read more
Catholic Prayer Lord Jesus Christ, I consecrate myself today anew and without reserve to your divine Heart. I consecrate to you my body with all its senses, my soul with all its faculties, my entire being. I consecrate to you all my thoughts, words and… Read more
Revelations 1 [8] I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty. [11] Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write… Read more
[6] For the LORD thy God blesseth thee, as he promised thee: and thou shalt lend unto many nations, but thou shalt not borrow; and thou shalt reign over many nations, but they shall not reign over thee. [7] If there be among you a… Read more
For as he thinketh in his heart, so is he… Proverbs 23:7 ___ The faith of all humans conforms to the nature of their mind. All people possess faith, and whatever the nature of their faith, that is verily what they are. Bhagavad Gita 17:3… Read more
New Shepard Launch I have been working at Blue Origin in Kent, WA since February 2019. This is an excellent work environment with engaging technical opportunities. Blue Origin is hiring engineers including some for vibroacoustics. Please see: https://www.blueorigin.com/careers Applicants must be a U.S. citizen or permanent… Read more
To fear God is to have absolute reverence and awe for an Almighty God, the Creator of all things. But the fear discussed in this post is the dread of potential loss or calamity. Turn your anxiety over to God. * * * Psalm 23:4… Read more