基于静强度与疲劳寿命分析的结构孔间距设计

Spacing Design of Structure Hole Based on Static Strength and Fatigue Life Analysis

摘要: 飞机结构疲劳损伤设计在航空工程领域中是目前大型客机损伤容限设计与分析的难点，孔作为飞机结构中的基本要素广泛存在，由于多孔之间应力相互干涉，并且存在孔边裂纹之间相互干扰导致疲劳寿命明显降低的现象，孔间裂纹演化规律更加复杂，值得深入研究。本文取双孔模型作为研究对象，以损伤力学为理论基础，对商用有限元软件ANSYS进行二次开发并对孔间裂纹扩展进行模拟分析，得到在避免显著提高应力集中效应或降低疲劳寿命的情况下的最小孔间距设计标准，具有良好的工程实用性和参考意义。

Abstract: In the field of aeronautical engineering, the fatigue damage design of aircraft structures is a difficult but critical point through the damage tolerance design of large civil aircraft. The interaction by the cracks between adjacent hole edges leads to a significant reduction in fatigue life, which is a typical issue of design. As an essential element in aircraft structure, holes are widely used in aircraft design. Compared with the single hole-edge crack problem, the fatigue crack propagation between holes is more complicated due to the above mutual interference. In this paper, the two-hole structure was taken as an example, and the finite element model was adopted to analyze the inter-hole stress and crack propagation, based on damage mechanics. Consequently, the optimal spacing criteria for design were established in the case of lower stress concentration effects and longer fatigue life.