Measuring roll cage tubes, first FEA analysed part

We measured the lengths for the roll cage tubing. We need 12m of the thicker and 42m of the thinner tube. The weight will be approximately 90 kg, and that's the weight of one passenger.

Calculations of needed tube lengths. Some tubes missing from the picture, e.g. the tubes where the shoulder harnesses are going to be mounted.

First Fea analysed part, the mounting for the shoulder harness for the middle seats, seems to hold up well.
I thought that we wouldn't need to make Fea models and calculations for this car, but I guess I was wrong. No sense in guessing if safety related parts will hold up. The solution reminds me of something in a roller coaster.

We decided early on not to model the roll cage in a Fea program. Even though the roll cage in itself is easy to model, it's interaction with the car body is very difficult to model. So it's very complicated to get reliable results for improving the stiffness of the car.