Hole size and crack length models for spacecraft walls under oblique hypervelocity projectile impact

All long-duration spacecraft in low-earth-orbit are subject to high speed impacts by meteoroids and orbital debris. In the event of a perforation, the pressure wall of a dual-wall structure impacted by a high-speed particle can also experience cracking and petalling. If such cracking were to occur on-orbit, unstable crack growth could develop which could lead to an unzipping of the impacted spacecraft module. The analysis presented in this paper extends the applicability of a crack length and hole size model developed previously for a normally impacted spacecraft wall to the case of obliquely incident particles. Predictions of the oblique impact model are compared with experimental data and the predictions of empirical hole size and crack length models. Modifications to the model that are required to bring its predictions in closer agreement with the experimental results are then presented and discussed.