I maintain a list of interesting robotics projects (https://github.com/msadowski/awesome-weekly-robotics https://github.com/msadowski/awesome-weekly-robotics).

I maintain a list of interesting robotics projects (https://github.com/msadowski/awesome-weekly-robotics https://github.com/msadowski/awesome-weekly-robotics). You will find a simulator section there but whether they are useful for you will depend on the details of your project. I don’t think it’s there but you could also check out MuJoCo.