Hi @meghrajvaidya and thanks for your questions!
First of all your project would require a vibro-acoustic module on our platform coupling the solid and fluid domains which we do not offer at the moment. I would recommend upvoting the existing request in our Vote For Features category.
Moreover 20dB is equivalent to someone whispering in a room. As a reference on circular saws, it is usually the saw blades that cause the high sound pressure level. With conventional saw blades, this level is always within the auditorily damaging range of 85 dB(A) and higher. ^1 So you could use noise-reduced saw blades!
Maybe some of our @power_users have some experience in this area and can give you information or tips on a workaround or another methods you might use to investigate such kind of problems. Let me know if you need any further help.
Source: ^1 http://www.dguv.de/ifa/fachinfos/laerm/laermarme-kreissaegeblaetter/index-2.jsp