Kundu Sudip, Jones Rhys, Peng Daren, Matthews Neil, Alankar Alankar, Raman Singh R K, Huang Pu
Centre of Expertise for Structural Mechanics, Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia.
Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400076, India.
Materials (Basel). 2020 Mar 15;13(6):1341. doi: 10.3390/ma13061341.
The USAF requirements for the durability and damage tolerance certification for additively manufactured (AM) aircraft structural parts, which are detailed in Structures Bulletin EZ-19-01, raise a number of new and, as yet, unanswered questions. The present paper attempts to address three questions: How to perform a fracture mechanics-based analysis of crack growth in an AM part so as to account for the residual stresses, how to perform a fracture mechanics-based durability analysis of a cold spray repair so as to account for both the induced residual stresses and the presence of multiple co-located cracks, and how to perform a fracture mechanics-based durability analysis of an AM part so as to account for the presence of multiple collocated surface braking cracks. In this context, the present paper reveals the potential of the Hartman-Schijve variant of the NASGRO crack growth equation to accurately predict the growth of each of the individual (collocated) cracks that arose in a cold spray-repaired specimen and in a specimen from a crack that nucleated and grew from a rough surface.
美国空军对增材制造（AM）飞机结构部件的耐久性和损伤容限认证要求，在《结构通报EZ-19-01》中有详细说明，这引发了一些新的、尚未得到解答的问题。本文试图解决三个问题：如何对增材制造部件中的裂纹扩展进行基于断裂力学的分析，以考虑残余应力；如何对冷喷涂修复进行基于断裂力学的耐久性分析，以考虑诱导残余应力和多个共位裂纹的存在；以及如何对增材制造部件进行基于断裂力学的耐久性分析，以考虑多个并置表面制动裂纹的存在。在此背景下，本文揭示了NASGRO裂纹扩展方程的哈特曼-希夫变体准确预测冷喷涂修复试样中以及从粗糙表面萌生并扩展的裂纹的试样中出现的每个单独（共位）裂纹扩展的潜力。
