# Simple Random Response Analysis

#### Introduction

Hello all,

My name is Will Asproth. I’m a student studying at the University of Minnesota. Summer 2023 I worked as an application engineering intern. My intern project was a random response analysis extension for Hyperworks HyperMesh.

For those who aren't familiar, random response analysis used when a structure is subjected to a non-deterministic continuous excitation. Think of structures subject to vibrations from a range of different frequencies at various intensities, and that the relative power of each frequencies vibration is only probabilistically defined, like the vibrations on an engine structure, turbulence on an airplane structure, or noise loads.

#### Objective

The objective of the extension was to produce random response outputs more easily than the current difficult time-consuming process workflow, in a way that was more like the tools offered by SimSolid or Patran Random.

- Smooth
- Simple
- Produce equivalent results

This tool uses an input frequency response analysis file and an input power spectral density curve. The tool also uses Compose to do calculations, so you'll also need a valid install 2022.1 or newer as well. I've provided example files that demonstrate the required formatting for your .h3d frequency response analysis result files and your .csv power spectral density curve files.

This tool doesn't support multi-direction excitation or imaginary scaling values, but does include more interpolation and integration schemes than the OptiStruct method.

#### Capabilities

The script can generate the following plots, values, or contours:

- output power spectral density plots
- root mean squared values
- positive zero crossing values
- continuous rms plots
- rms contours

In addition, the script can produce **Segalman Von Mises** or phase dependent magnitudes contours or values.

You can choose an interpolation and integration scheme and a desired frequency range.

The script includes example inputs and outputs as well as documentation and step-by-step video tutorial stored in the documentation folder inside the script.

#### Conclusion

I leaned a ton about random response analysis, Compose, and the HyperWorks extension space with this project. It might be a good example of a simple script that integrates the extension framework with the Compose batch runner.

- Example of OML/TCL integration
- Replicates OS results for simple RRA
- Simple HW extension demo