scholarly journals Damage resistance of composite structures with unsymmetrical stacking sequence subjected to high velocity bird impact

2020 ◽  
Vol 1 ◽  
pp. 100002 ◽  
Author(s):  
Michael May ◽  
Sonja Arnold-Keifer ◽  
Thomas Haase
Keyword(s):  
High Velocity ◽  
Composite Structures ◽  
Stacking Sequence ◽  
Damage Resistance ◽  
Bird Impact

Optimum design of composite structures with ply drop-offs using response surface methodology

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Camila Aparecida Diniz ◽  
Yohan Méndez ◽  
Fabrício Alves de Almeida ◽  
Sebastião Simões da Cunha Jr ◽  
G.F. Gomes
Keyword(s):  
Response Surface Methodology ◽  
Natural Frequency ◽  
Design Variable ◽  
Composite Structures ◽  
Laminate Plate ◽  
Longitudinal Direction ◽  
Stacking Sequence ◽  
Direct Influence ◽  
Optimization Strategy ◽  
Content Type

Purpose Many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, it is necessary to optimize other parameters that have a direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction. That way, the purpose of this study is to find the most significant design variables relative to the drop-off location considering the transversal and longitudinal positions, seeking to achieve the optimal combination of ply drop-off locations that provides excellent performance for the laminate plate. Design/methodology/approach This study aims to determine the optimal drop-off location in a laminate plate using the finite element method and an approach statistical with design of experiments (DOE). Findings The optimization strategy using DOE revealed to be satisfactory for analyzing laminate structures with ply drop-offs, demonstrating that not all design factors influence the response variability. The failure criterion response variable revealed a poor fit, with an adjusted coefficient of determination lower than 60%, thus demonstrating that the response did not vary with the ply drop-off location. Already the strain and natural frequency response variables presented high significance. Finally, the optimization strategy revealed that the optimal drop-off location that minimizes the strain and maximizes the natural frequency is the ply drop-off located of the end plate. Originality/value It was also noted that many researchers prefer evolutionary algorithms for optimizing composite structures with ply drop-offs, being scarce to the literature studies involving optimization strategies using response surface methodology. In addition, many studies only take into account the ply stacking sequence as the design variable to determine the optimal ply drop-off location; however, in this study, the authors investigated other important parameters that have direct influence on the ply drop-off site such as which plies should be dropped and in which longitudinal direction.

A General Ply Design for Aero Engine Composite Fan Blade

2017 ◽  
Author(s):  
Jiaguangyi Xiao ◽  
Yong Chen ◽  
Qichen Zhu ◽  
Jun Lee ◽  
Tingting Ma
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Stacking Sequence ◽  
Composite Blade ◽  
Arduous Task ◽  
Aero Engine ◽  
Margin Of Safety ◽  
Fan Blade ◽  
The Impact ◽  
Ply Orientation

Composite fan blade ply lay-up design, which includes ply drop-off/shuffle design and stacking sequence design, makes fan blade structures different from traditional composite structures. It gives designers more freedom to construct high-quality fan blades. However, contemporary fan blade profiles are quite complex and twisted, and fan blade structures are quite different from regular composite structures such as composite laminates and composite wings. The ply drop-off design of a fan blade, especially for a fully 3D fan blade, is still an arduous task. To meet this challenge, this paper develops a ply lay-up way with the help of a software called Fibersim. The fully 3D fan blade is cut into ply pieces in Fibersim. As a result, an initial ply sequence is created and ply shuffle could revise it. Because of the complexity of ply shuffling, the ply shuffle table developed in this paper mainly refers to the design experience gained from simple plate-like laminate structures and some criterion. Besides, the impact of different ply orientation patterns on the reliability of composite fan blade is studied through static and modal numerical analysis. The results show that this ply lay-up idea is feasible for aero engine composite fan blade. Under the calculated rotating speeds, the ply stacking sequence 4 (i.e.[−45°/0°/+45°/0°] with the outer seven groups are [−45°/0°/−45°/0°]) shows the greatest margin of safety compared with other stacking sequences. Modal analysis shows that plies with different angles could have relatively big different impacts on blades vibration characteristics. The composite fan blade ply design route this paper presents has gain its initial success and the results in this paper might be used as basic references for composite blade initial structural design.

Damage Development in CFRP Laminates under Impact Loading

2006 ◽  
Vol 326-328 ◽  
pp. 1833-1836 ◽  
Author(s):  
Seung Min Jang ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji
Keyword(s):  
Impact Damage ◽  
Stacking Sequence ◽  
Absorbed Energy ◽  
Damage Development ◽  
Damage Resistance ◽  
Cfrp Laminates ◽  
Impact Tester ◽  
Weight Impact ◽  
The Impact ◽  
Delamination Area

The development characteristics of impact-induced damage in carbon-fiber-reinforcedplastics (CFRP) laminates were experimentally studied using a drop-weight impact tester. Five types of CFRP laminates were used to investigate the effect of stacking sequences and thicknesses. The efficiency of absorbed energy to impact energy was different for CFRP laminates with different stacking sequences or thicknesses. The DA/AE ratio of delamination area (DA) to absorbed energy (AE) was almost the same for CFRP laminates with the same stacking sequence regardless of the thickness. We found that the DA/AE ratio could be used as a parameter to characterize the impact damage resistance in CFRP laminates with different stacking sequences.

Finite Element-Based Parametric Investigations of the Stepped-Lap Repairs to Laminated Cylindrical Shell

2011 ◽  
Vol 90-93 ◽  
pp. 2682-2690
Author(s):  
Jian Xin Xu ◽  
Lu Chun Zhao ◽  
Ding He Li
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Cylindrical Shells ◽  
Fe Model ◽  
Stacking Sequence ◽  
Improve Design ◽  
Analysis Techniques ◽  
Insight Into ◽  
Laminated Cylindrical Shell ◽  
Load Conditions

A parametric finite element (FE) model was developed to allow a broad investigation into the influence of various parameters, such as load conditions, stacking sequence and the number of steps on the performance of the stepped-lap repairs in composite laminated cylindrical shells. And the peak stresses determined with respect to changes in stacking sequence and the number of steps. Furthermore, the adhesive stress distribution resulting from joining mismatched laminate cylindrical shells was investigated. The results of this investigation provide further insight into the stresses that develop in stepped repairs of composite structures under load. This insight may lead to improve design and analysis techniques of stepped repairs in composite structures.

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