Prediction of Compression-After-Edge-Impact (CAEI) behaviour in composite panel stiffened with I-shaped stiffeners

Abstract

A phenomenological-based mechanical finite element model is developed for the prediction of ultimate compression loads and failure modes of wing relevant composite panels stiffened with I-shaped stiffeners, of which the edge is subjected to impact loading. The initiation of intralaminar failure including fiber and inter-fiber fracture is evaluated by Puck criteria, and its evolution is assumed to be controlled by equivalent strains. The interlaminar failure, namely delamination, is simulated by employing a surface-based cohesive contact model. For R-sections of the impacted stiffener, interfacial delamination, which may cause premature failure and to some extent reduce the load carrying capacity, is efficiently considered. A good correlation between the experimental and numerical results shows correctness and effectiveness of the proposed mechanical method for predicting CAEI response. Furthermore, numerical results reveal that not only failure propagation of the impacted site but that of the other undamaged side dominate the compressive mechanism of the edge impacted stiffener, of which

Experimental study of post-buckled single-stringer composite specimens under fatigue loads with different load levels and load ratios

“…A few authors have experimentally investigated and reported the buckling and post-buckling behavior of composite stiffened structures under quasi-static and fatigue compressive loads [19][20][21], although these test campaigns only consider one combination of load level and load ratio. Recent experimental works include research on the propagation of an artificial delamination or impact damage in post-buckling conditions of hat-stiffened [22], T-stiffened [23], I-stiffened [24], and J-stiffened panels [25]; highlighting the strive for gaining further knowledge on this topic to increase the component structural efficiency.…”

A Numerical Assessment of the Influence of Local Stress Ratio in the Fatigue Analysis of Post-Buckled Composite Single-Stringer Specimen

“…Compared to previous research activities, in this paper, the developed numerical methodology is validated with results obtained from an extensive in-house experimental testing campaign, which provided access to unique data not available in the literature [24]. Few works of research can be found in the literature where the buckling and post-buckling behavior of composite stiffened structures under fatigue compressive loads is experimentally investigated for different type of stringer [25,26]. The SSC specimen was conceived to emulate the performance of large multi-stringer panels commonly found in fuselage structures [27].…”

The research of buckling and post-buckling behavior of bidirectional stiffened composite panel under discrete impact

“…Liu (2020) conducted a CAI test on the stiffened panels with cap bar and discussed the influence of different impact damage locations on the residual strength. Based on experimental research and engineering algorithm, Li and Chen (2016a, b, 2017) studied the compression failure mechanism of T-type and I-type stiffened panels with edge impact, and the results showed that the rounded corners of stiffened panels were prone to stratify. Zhang and Zhenyu (2021) manufactured the cylindrical grid structure and carried out uniaxial compression tests to evaluate its compressive performance.…”