Worst-case structural analysis

Abstract

Direct digital manufacturing is a set of rapidly evolving technologies that provide easy ways to manufacture highly customized and unique products. The development pipeline for such products is radically different from the conventional manufacturing pipeline: 3D geometric models are designed by users often with little or no manufacturing experience, and sent directly to the printer. Structural analysis on the user side with conventional tools is often unfeasible as it requires specialized training and software. Trial-anderror, the most common approach, is time-consuming and expensive.We present a method that would identify structural problems in objects designed for 3D printing based on geometry and material properties only, without specific assumptions on loads and manual load setup. We solve a constrained optimization problem to determine the "worst" load distribution for a shape that will cause high local stress or large deformations. While in its general form this optimization has a prohibitively high computational cost, we demonstrate that an approximate method makes it possible to solve the problem rapidly for a broad range of printed models. We validate our method both computationally and experimentally and demonstrate that it has good predictive power for a number of diverse 3D printed shapes.

Fab forms

“…Algorithms for testing design robustness have been developed for decades in the field of engineering (e.g. probabilistic sensitivity analysis [Doubilet et al 1984;Wu 1994]), and have recently also caught the attention of the graphics community with works such as computational structural analysis [Zhou et al 2013], automatic correction for areas of high stress [Stava et al 2012] and semi-automatic correction of model stability [Prévost et al 2013]. With the exception of fast approximate methods such as [Umetani and Schmidt 2013], comprehensive checks of model durability and functionality typically require costly simulation, making them impractical during interactive customization.…”

Cross section-based hollowing and structural enhancement

“…Zhou et al [44] propose an optimization framework to analyze all weak regions without specific external loads. However, the finite element method (FEM) used in their algorithms is time-consuming when the input models are complex.…”

Cost-effective printing of 3D objects with skin-frame structures

“…Quite a few topics in 3D fabrication, including structural analysis [Stava et al 2012;Zhou et al 2013], segmentation [Luo et al 2012], articulated model generation [Bächer et al 2012;Calì et al 2012], and balancing shape [Prévost et al 2013], have been researched in computer graphics recently. Based on finite element analysis of stress, the approach of [Stava et al 2012] can strengthen printed objects by hollowing, local thickening, and adding extra struts.…”