Physics-Based Probabilistic Design Tool with System-Level Reliability Constraint

The work proposed herein would establish a concurrent design environment that enables aerospace hardware designers to rapidly determine optimum risk-constrained designs subject to multiple uncertainties in applied loads, material properties, and manufacturing processes. This means that the design process no longer would consist of a sequence of separate code invocations to: (1) obtain the geometry model, (2) determine the various loads, (3) determine performance, (4) perform a structural analysis, (5) perform design optimization, and (6) perform a probabilistic risk assessment. Instead, all of these functions would be automatically incorporated into a single framework using existing physics-based deterministic modeling codes and a set of computer-generated data transfer interfaces. Thus, a design engineer would be able to rapidly explore the design space to identify the minimum weight design that meets a given reliability constraint ? thereby avoiding both an overly conservative design and a too-risky design. For example, the software tools that implement this innovation could be used to determine the wall thickness of a launch vehicle's external cryogenic propellant tanks exposed to high but uncertain thermal and aerodynamic loads and with a reliability probability of 0.99999.