A function for calculating the natural frequencies and mode shapes for an elastic beam undergoing rotation is given in: Matlab script: Vibrationdata Signal Analysis Package The function can be accessed via: >> vibrationdata > Miscellaneous > Structural Dynamics > Beam Bending FEA > Rotating Beam,… Read more
Highly Accelerated Life Testing (HALT) is a process for ruggedization of preproduction products. It is also referred to as AST (Accelerated Stress Testing). Highly Accelerated Stress Screening (HASS) is the production screen for products once they have been characterized in HALT. HALT and HASS each use… Read more
A function for calculating the natural frequencies and mode shapes for an elastic beam supported by end springs is included in: Matlab script: Vibrationdata Signal Analysis Package The function can be accessed via: >> vibrationdata > Miscellaneous > Structural Dynamics > Beam Bending > Beam… Read more
Maximum predicted environment (MPE) levels can be derived for acoustic, shock, and vibration levels where flight data is available. The enveloping for multiple sets of data can be performed using tolerance factors as described in the following papers. Normal Tolerance Factors for Upper Tolerance Limits:… Read more
Here are some papers: Electronic Circuit Board Design Reliability Lessons Learned: electronics_design_reliability.pdf Effect of Conformal Coating on Circuit Board Vibration Response: conformal_coat.pdf * * * Steinberg’s Vibration Analysis for Electronic Equipment describes the methods for designing electronic equipment that must work with a high degree of… Read more
I have added a function for calculating the free vibration response of an SDOF system to initial conditions to the Vibrationdata GUI package. Matlab script: Vibrationdata Signal Analysis Package >> vibrationdata > Miscellaneous > Structural Dynamics > Spring-Mass Systems > SDOF Free Vibration Response to… Read more
I am currently researching IEEE Std 693… One of its recommended shaker test methods for power equipment is to use a “sine beat” acceleration time history. The main frequency is selected as the equipment’s natural frequency. The minimum number of beats is 5 with a… Read more
A function for calculating cylindrical shell natural frequencies via the wave method is now included in the Vibrationdata GUI package. Matlab script: Vibrationdata Signal Analysis Package This function may be accessed via: vibrationdata > Structural Dynamics > Rings & Cylinders > Cylinder, Wave Model Reference… Read more
The following is mostly an academic problem. The Response of an Undamped Two-degree-of-freedom System Subjected to Base Displacement via Modal Analysis: twodof_base_disp_modal.pdf The Response of an Undamped Two-degree-of-freedom System Subjected to Base Displacement via Laplace Transforms: twodof_base_disp_Laplace.pdf * * * See also: Two-degree-of-freedom Systems – Tom… Read more
Sloshing can occur in swimming pools, trucks carrying liquids, rocket vehicle propellant tanks and in other situations. Sloshing of propellants may adversely affect the stability of a space vehicle and the integrity of the tank structure. Sloshing describes the free-surface oscillations of fluid in a… Read more