论文标题
在多点协调的负载频谱下对复合直升机尾结构的效率，低速冲击和疲劳行为进行建模
Modelling Pre-fatigue, Low-velocity Impact and Fatigue behaviours of Composite Helicopter Tail Structures under Multipoint Coordinated Loading Spectrum
论文作者
论文摘要
本文的目的是在多尺度的复合材料直升机尾巴结构下，在多尺度配位加载频谱下研究全尺度复合材料直升机尾结构的数值，低速冲击（LVI）和疲劳渐进损伤行为。首先，提出了一种疲劳渐进损伤模型（PDM），该模型纳入了多轴疲劳残留强度降解规则，基于疲劳残留强度概念和突然的僵硬降解规则的疲劳失败标准。然后，开发了平原织物（PW）和单向（UD）复合材料的LVI渐进式损害模型。此外，提出了具有合理的损伤转移策略，用于fatigue，LVI和疲劳渐进式损害分析的完整过程分析算法。最后，建立了高度计算的高效和准确的全尺度全尺度全局局部有限元（FE）模型，以预测在两个飞行工作条件下的应变分布，以预测在撞击负荷下的LVI损害，并评估在多点配位负载频谱下进行疲劳损伤行为。数值预测与这项工作和文献数据的测试结果非常吻合，表明开发的效率前，LVI，疲劳PDM和算法以及基于壳向固体耦合的全球 - 局部FE建模可以有效地分析全幕集飞机结构的影响损害的影响。
This paper aims to numerically study the pre-fatigue, low-velocity impact (LVI) and fatigue progressive damage behaviours of a full-scale composite helicopter tail structure under multipoint coordinated loading spectrum. First, a fatigue progressive damage model (PDM) incorporating multiaxial fatigue residual strength degradation rule, fatigue failure criteria based on fatigue residual strength concept and sudden stiffness degradation rule was proposed. Then, an LVI progressive damage model for plain-weave (PW) and unidirectional (UD) composites was developed. Moreover, a full-process analysis algorithm with a reasonable damage transfer strategy for pre-fatigue, LVI and fatigue progressive damage analysis was proposed. Finally, a highly computational efficient and accurate full-scale global-local finite element (FE) model of helicopter tail structure was built to predict strain distribution under two flight working conditions, to predict LVI damage under impact loading, and to assess fatigue damage behaviours under multipoint coordinated loading spectrum. The numerical predictions agree well with test results from this work and literature data, indicating that the developed pre-fatigue, LVI, fatigue PDMs and algorithms, as well as the global-local FE modelling based on shell-to-solid coupling, can effectively analyse the impact damage tolerance of full-scale aircraft structures.
