Alright, OP, here's what I've come up with (feel free to change it to your liking):
PCPartPicker part list /
Price breakdown by merchant
CPU: AMD - Threadripper 1920X 3.5GHz 12-Core Processor ($1059.00 @ Mwave Australia)
CPU Cooler: Corsair - H100i v2 70.7 CFM Liquid CPU Cooler ($138.00 @ Shopping Express)
Motherboard: ASRock - X399 Taichi ATX TR4 Motherboard ($299.00 @ PCCaseGear)
Memory: Kingston - ValueRAM 16GB (1 x 16GB) DDR4-2400 Memory ($292.60 @ Newegg Australia)
Memory: Kingston - ValueRAM 16GB (1 x 16GB) DDR4-2400 Memory ($292.60 @ Newegg Australia)
Storage: Samsung - 970 Evo 250GB M.2-2280 Solid State Drive ($145.00 @ Centre Com)
Storage: Western Digital - Blue 1TB M.2-2280 Solid State Drive ($299.05 @ Amazon Australia)
Video Card: PNY - Quadro P2000 5GB Video Card ($753.00 @ Amazon Australia)
Case: NZXT - S340 Elite (White) ATX Mid Tower Case ($134.20 @ Newegg Australia)
Power Supply: SeaSonic - FOCUS Plus Gold 750W 80+ Gold Certified Fully-Modular ATX Power Supply ($169.00 @ PCCaseGear)
Operating System: Microsoft - Windows 10 Pro OEM 64-bit ($184.00 @ Shopping Express)
Total: $3765.45
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-07-24 04:24 AEST+1000
ALL OF THIS DEPENDS ON YOUR LICENSE:
The 1920X strikes a happy medium between frequency and core-count. If you want more cores, the 1950X (16 cores is around 300 AUD more). Core i9 chips dont even support ECC (for whatever reason, so much for SHEDT huh?).
I went with 32GB because I don't know the scale/size of your projects. 64GB is pricey and might not even be necessary for your work case.
Storage was a bit interesting and you have a few options here. I went with a 970 Evo to store Windows, Solidworks, and the rest of your software on. You could probably squeeze in a few of your projects as well, but space would be a bit cramped. That's why I went with a 1TB SSD, given you could easily transfer projects that you want archived to it, while still retaining fast loading times. Additionally, you could go for a 500GB 970 Evo and a high-capacity HDD, then ditch the 1TB SSD. It's all particular to your use case.
The GPU was a bit interesting. The p2000 is a great entry-level card, but from what I've read Ansys likes a faster CPU more than any good GPU, unless you're doing CFD simultaneously. Otherwise, it's also a very good chip for Solidworks etc.
The rest of the stuff is personal preference, but will still perform very well for your use case. If you require ECC REGISTERED RAM, then the only direction I can point you in would be the Xeons (significantly more expensive.)