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Failure Analysis of Hat-Stringer-Stiffened Aircraft Composite Panels under Four-Point Bending Loading
Binkai Li1, Yu Gong2, Yukui Gao3,4
1School of Aerospace Engineering and Applied Mechanics, Tongji University, Zhangwu Road 100#, Shanghai 200092, China.
Materials (Basel, Switzerland)
|April 12, 2022
Summary
This study investigates the static and fatigue failure of hat-stringer-stiffened composite panels under bending. A new fatigue damage model accurately predicts panel failure, crucial for aircraft safety.
Area of Science:
- Materials Science
- Mechanical Engineering
- Aerospace Engineering
Background:
- Hat-stringer-stiffened composite panels are vital aircraft components.
- Existing research inadequately addresses failure under radial pressure.
- Accurate failure analysis is critical for fuselage safety and integrity.
Purpose of the Study:
- To investigate the static and fatigue failure of hat-stringer-stiffened composite panels.
- To develop and validate a novel theoretical model for fatigue failure prediction.
- To analyze failure under four-point bending loading, simulating service conditions.
Main Methods:
- Experimental testing of composite panels under static and fatigue loading.
- Numerical simulations using Abaqus with a user-defined subroutine (USDFLD).
- Development of a theoretical model based on fatigue damage theory.
Main Results:
- Identified primary failure modes: skin delamination and skin-flange debonding.
- Static tests showed average initial debonding at 897.3 N and 10.8 mm.
- Fatigue tests revealed an average failure life of 33,085 cycles.
- Numerical predictions closely matched experimental results (within 10% error).
Conclusions:
- The proposed theoretical model and numerical method reliably predict composite panel failure.
- The findings are applicable to understanding and preventing failures in hat-shaped girder structures.
- This research enhances the safety and integrity analysis of aircraft fuselages.
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