  An important task in structural design is to quantify the structural
performance of an object under the external forces it may experience during its
use. The problem proves to be computationally very challenging as the external
forces' contact locations and magnitudes may exhibit significant variations. We
present an efficient analysis approach to determine the most critical force
contact location in such problems with force location uncertainty. Given an
input 3D model and regions on its boundary where arbitrary normal forces may
make contact, our algorithm predicts the worst-case force configuration
responsible for creating the highest stress within the object. Our approach
uses a computationally tractable experimental design method to select number of
sample force locations based on geometry only, without inspecting the stress
response that requires computationally expensive finite-element analysis. Then,
we construct a simple regression model on these samples and corresponding
maximum stresses. Combined with a simple ranking based post-processing step,
our method provides a practical solution to worst-case structural analysis
problem. The results indicate that our approach achieves significant
improvements over the existing work and brute force approaches. We demonstrate
that further speed- up can be obtained when small amount of an error tolerance
in maximum stress is allowed.
