南京航空航天大学学报（英文版）2026，Vol.43Issue(1)：85-94,10.DOI:10.16356/j.1005-1120.2026.01.007
结构裂纹扩展飞续飞谱的等效常幅谱设计方法与试验验证
Equivalent Constant Amplitude Spectrum Design Method and Experimental Verification of Structural Crack Growth Flight-by-Flight Spectrum
摘要
Abstract
In fatigue damage tolerance verification tests of aircraft structures,the simulation and loading of flight-by-flight spectra require considerable time and resources.To improve the efficiency of load spectrum design and testing,an equivalent constant-amplitude spectrum design method for flight-by-flight spectra is proposed based on the equivalence of crack growth behavior.By combining the Paris crack growth model with the Walker stress ratio correction,the equivalent stress amplitude is directly calculated using structural parameters and load spectrum characteristics,enabling a rapid transformation from variable-amplitude spectra to constant-amplitude spectra.The original spectrum is discretized based on the load-exceedance curve,and the equivalence relationship between multi-level block spectra and constant-amplitude spectra is established.Taking a typical lower wing skin structure of a transport aircraft as an example,two equivalent spectra are designed and validated through fatigue crack growth tests on 2024-T351 center-hole plate specimens.The experimental results show that the fatigue life deviation between the equivalent spectra and the original flight-by-flight spectrum is within 10%,demonstrating the effectiveness of the proposed method.Moreover,the equivalent spectrum constructed under the condition of invariant mean flight stress exhibits higher equivalence accuracy.The influence of spectral shape on the equivalent stress amplitude is further analyzed,revealing that the equivalent stress amplitude increases with the spectrum shape coefficient.The proposed method provides a useful reference for load spectrum design in aircraft structural damage tolerance verification tests.关键词
飞机结构/裂纹扩展/疲劳载荷谱/等效试验/应力强度因子Key words
aircraft structure/crack growth/fatigue load spectrum/equivalent test/stress intensity factor分类
航空航天引用本文复制引用
朱高尚,赵洽,曹镜..结构裂纹扩展飞续飞谱的等效常幅谱设计方法与试验验证[J].南京航空航天大学学报（英文版）,2026,43(1):85-94,10.基金项目
This work was supported by the Na-tional Natural Science Foundation of China(No.52075244). （No.52075244）
