The Newmark-beta method can be used to solve structural dynamics problems in the time domain, of the form: M (d^2x/dt^2) + C dx/dt + K x = F This method performs direct integration on the mass, damping and stiffness matrices which may be fully-coupled. Here… Read more
Here is a method for converting modal damping to a damping coefficient matrix for all modes. It is based on a pseudo inversion of the modal damping matrix. The resulting coefficient matrix will be fully populated. The damping terms will not necessary corresponding to physical dashpots,… Read more
The Newmark-beta method can be used to solve structural dynamics problems in the time domain, of the form: M (d^2x/dt^2) + C dx/dt + K x = F This method performs direct integration on the mass, damping and stiffness matrices which may be fully-coupled. Here… Read more
A transfer function is a type of frequency response function (FRF) that gives the steady-state response to a force input as a function of frequency. Transfer functions for structural dynamics problems can be calculated from the natural frequencies, modal damping ratios and normal modes. This… Read more
Finding the the natural frequencies of a continuous beam, plate, membrane or even an acoustical volume requires solving for the eigenvalue roots of a characteristic equation, which may contain trigonometric or Bessel functions. Matlab provides an fzero function which can be used for this purpose.… Read more
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
The Craig-Bampton method is method for reducing the size of a finite element model, particularly where two or more subsystems are connected. It combines the motion of boundary points with modes of the subsystem assuming the boundary points are held fixed. Here is a tutorial… Read more
The Vibrationdata Signal Analysis Package has a function for calculating the natural frequencies of a plate simply-supported about all edges. The package also has options for calculating the response to base excitation. Vibrationdata > Structural Dynamics > Plates, Rectangular & Circular > Rectangular Plate, Simply Supported The… Read more
Shock and vibration environments produce dynamic stresses which can cause material failure in structures. The potential failure modes include fatigue, yielding, and ultimate stress limit. F.V. Hunt wrote a seminal paper on this subject, titled “Stress and Stress Limits on the Attainable Velocity in Mechanical… 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