My husband is an insurance damage appraiser. If you own the car outright, you are free to do with it as you wish. Repair, don't repair, partial repair, etc. If there is a loan on the car, the check would have been made out to you and the lien holder jointly so you wouldn't have been able to deposit that money, so i would assume that you don't have a loan. If you do have a loan, you do need to have the repair done because it affects the value of the car, which is the collateral on the loan.
If you don't get the repair done, when you go to sell the car, it will be worth less due to the damage. If you got into another accident and the car was a total loss, your insurance company would deduct the value of what they paid out already from the total loss payout. If you get into another accident that's repairable, only the loss from that accident would be a covered repair and the shop wouldn't be able to fix the prior damage without charging you.
In accidents, we've both repaired and not repaired depending on the damage, the condition of the car, whether or not we expected to sell it or drive it into the ground, etc. There is nothing fraudulent about not getting the repair done.