A method for certifying a design of a liquid container onboard a vehicle for manufacture of the liquid container is provided. The method includes generating a computer geometric model of the liquid container according to the design, and executable code to reproduce dynamics and operational parameters of the vehicle, with the dynamics of the vehicle including dynamics during a vehicle maneuver that is selectable from a database of vehicle dynamics for a plurality of vehicle maneuvers. The method includes executing a simulating application to perform a simulation of liquid sloshing in the liquid container onboard the vehicle is performed subject to the dynamics and operational parameters, and iterate the simulation to refine a prediction of loads and stresses on the liquid container from the simulation produced thereby. Locations within the liquid container more vulnerable to fatigue-risk are identified based on the prediction, and output for certification of the design.