Coming here after reading your email. I don't have any specific answer though, rather questions.
I am dealing with similar issue.
For my research I needed to simulate and optimize a Helmholtz resonator geometry to achieve good Absorption Coefficient. However, I'm struggling if it can be done in Pachyderm or not. Since, absorption is based on wave propagation of sound.
As of now physics based platforms such as COMSOL can be used (which isnt easy to access). If anyone has any insight into this, please help!
Pachyderm is a plug In to investigate Room Acoustics, which means, it will give you information about the soundpressure field in an enclosure. No vibrational /dynamic processes are modelled with pachyderm.
As a rough example, Pachyderm can tell you how long the reverberation time is in your living room but it can't tell you by how many milimeters does a floating floor get displaced if you place a machine on top of it.