admin Here is a good website for curve-fitting: zunzun From the website… Here you can curve fit and surface fit your 2D and 3D data online with a rich set of error histograms, error plots, curve plots, surface plots, contour plots, VRML, auto-generated source code, and… Read more
This blog entry is a work-in-progress. Fatigue analysis can be performed in the time domain using rainflow cycle counting. This is an elegant, brute-force approach. One advantage of the time domain approach is that it tends to highlight the occurrences of peaks above 3-sigma for… Read more
These Matlab scripts calculate the response of a single-degree-of-freedom system to base excitation: sdof_base.zip sdof_base.m is the main script. The remaining scripts are supporting functions. The base excitation may be a half-sine pulse, terminal sawtooth pulse, arbitrary pulse, or a PSD. * * * See… Read more
Functions for calculating the response of a two-degree-of-freedom system to base excitation are given in the Vibrationdata analysis package posted at: Matlab script: Vibrationdata Signal Analysis Package * * * See also: Two-degree-of-freedom Systems * * * – Tom Irvine
Here is a set of scripts that calculate the natural frequencies and mode shapes for a two-degree-of-freedom system. The scripts are posted at: two_dof_system.zip The main script is: two_dof_system.m The remaining scripts are supporting functions. * * * See also: Two-degree-of-freedom Systems – Tom Irvine
The Dunkerely method is used to estimate the lower natural frequency limit for a system of connected subsystems. It complements the Rayleigh method which gives an upper limit estimate. A Matlab script for performing this estimate is given in Dunkerley.zip More later…. – Tom Irvine
These Matlab scripts determine an optimum envelope for an acceleration power spectral density: envelope_plateau.zip The optimum envelope is the that which yields the lowest GRMS and Velocity RMS values. The acceleration is assumed to be the base excitation for an array of independent, parallel single-degree-of-freedom… Read more
Revised software uploaded on January 9, 2013 Accelerometers signals for pyrotechnic events often have spurious offsets. Numerous potential causes include: 1. Excitation of the accelerometer’s piezoelectric crystal natural frequency 2. Signal conditioner overload 3. Base strain sensitivity 4. Instrumentation noise 5. Electromagnetic interference These causes… Read more
These Matlab scripts calculate the natural frequencies and normal modes of a flat rectangular plate via the finite element method: rectangular_plate_fea.zip rectangular_plate_fea.m is the main script. The remaining scripts are supporting function. Rectangular elements are used for the numerical model, but the plotting elements are… Read more
Here is a set of Matlab GUI scripts for calculating the bending frequencies of both homogeneous and honeycomb-sandwich circular plates: circular_plate.zip * * * Here is a set of Matlab GUI scripts for calculating the bending frequencies of both homogeneous and honeycomb-sandwich annular plates: annular_plate.zip *… Read more