Do F1 teams change their suspensions over the course of the year?
Teams change their suspension over the course of the season for a number or reasons. Structural safety, for example, could be one of them. Teams know exactly how much load their suspension can take; in fact, during every session a structural system engineer will monitor the live telemetry to make sure the load limits are not exceeded.
If there are any concerns about the structural safety, the team will change the suspension. Another reason to introduce new suspension elements is upgrades to the car - either to the suspension itself or to its aerodynamic characteristics. Some components of the suspension like the wishbones or the steering arm are out in the airflow, so they have a big impact on the airflow around the car.
Finally, a team might introduce new suspension for a specific track. For the Monaco Grand Prix, for example, the team brought special front suspension to make sure the car could handle the unique challenges of the streets of Monte Carlo.
Monaco features the tightest turn of the season, the famous Fairmont hairpin (aka Loews) which requires more steering lock than any other corner. Compared to the hairpin corner in the upcoming Canadian Grand Prix (Turn 10), an extra 40 percent of lock is needed for Loews hairpin.
The turn is so tight that the regular suspension would limit the choice of driving line through the hairpin or that the drivers would have to turn the steering wheel multiple times. The special front suspension the team brought to Monaco allowed for a bigger road wheel angle, so that the drivers could attack the hairpin in the way they wanted.