The increasing level of automation in safety-critical applications such as automated driving leads to additional requirements for functional availability of mechatronic systems. It is thus important to consider fail-operability and functional safety in order to optimize the performance and cost of the overall system in early design phases. The evaluation of feasible designs requires also the analysis of possible malfunctions and robustness of appropriate safety mechanisms in erroneous system states. This includes the examination of not only single faults but also of the sequence and impact of possible fault combinations in dynamic systems. The work presented in this paper proposes a methodology and a modeling approach suitable for the design exploration of mechatronic systems under consideration of functional safety. It enables to automatically generate feasible design variants by varying the functional system architecture at different abstraction levels and by mapping the functions to a set of hardware components. Furthermore, it combines logical and behavioral modeling with the goal to automatically evaluate the impact of component failures for various design variants under consideration of system dynamics and possible reconfigurations. A stochastic process of each design variant is set up automatically to estimate relevant safety metrics. The applicability and benefits of the proposed model-based design exploration of fail-operational mechatronic systems are demonstrated on exemplary drivetrain variants by investigating multiple safety mechanisms at different abstraction levels.