I have installed Linux Ubuntu on my 64-bit Windows PC, turning it into a dual boot configuration. The link is: http://www.ubuntu.com/download/ubuntu/windows-installer * * * I have also installed the Linux versions of Python & Spyder. Here is a Python installation method from Nick Smith: Part… Read more
Every Python book and website tutorial recommends the following command for prompting the user for input: raw_input() But I have found that this command is buggy and unreliable. Specifically, I wrote a long, complex code that had several raw_input() commands. The code ran successfully in… Read more
The Python scripting program, ver 2.7.2, can be freely downloaded from: http://www.python.org/download/ Programmers will also need to install libraries such as NumPy, SciPy and matplotlib, particularly for science and engineering programming. These libraries are also freely available, but their proper installation and integration with Python is tricky. As… Read more
I had the opportunity today to speak with several engineers from the Aerospace Corporation. They said that their organization is beginning a gradual transition from Matlab to Python. Python is an interpreted, interactive, object-oriented, open-source programming language. In addition, numerical library functions are available for Python.… Read more
Again, I will present a paper on my NESC shock & vibration educational materials at the Aerospace Spacecraft & Launch Vehicle Dynamic Environments Conference, in El Segundo, California, June 7-9, 2011. I hope to meet some of you there. You may download the presentation at:… Read more
Here is a survey question. NASA-HDBK-7005(2001) gives the Franken method as a semi-empirical method for predicting the vibration response of a cylindrical skin to an acoustic pressure field, via extrapolation. Franken originally published this method in 1962 based on rocket engine static test fire data.… Read more
Some NASA colleagues and I visited SpaceX in Hawthorne, California, on Thursday. Thanks to SpaceX engineers Sam DiMaggio and Jessica Jensen for the guided tour. We saw a Dragon spacecraft being built, as well as several rocket engines. Sam DiMaggio, who leads the loads and… Read more
This week I participated in an NESC conference in Los Angeles. One of my colleagues brought up the following point. Finite element models are created to represent physical models for analysis purposes. The finite element model natural frequencies can then be compared to data from… Read more
I recently had a need to compare sound pressure levels (SPLs) on the inside of payload fairings for a number of launch vehicles. These levels are readily available in online user’s guide for vehicles such as Atlas, Delta, Falcon, Ariane and others. The most critical… Read more
Greetings, I will be posting news about my shock & vibration research and latest software and tutorials on this blog. I am currently serving as a industry representative on the NASA Engineering & Safety Center (NESC), Technical Disciplines Team for Loads & Dynamics, under the leadership… Read more