Higher strength of double-double over traditional quad laminates in equal-stiffness design of single lap joint

IF 5.7 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures Pub Date : 2025-03-29 DOI:10.1016/j.tws.2025.113255

Yizhou Huang , Cheng Qiu , Zongkai He , Yile Hu , Guangyong Sun , Jinglei Yang

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引用次数: 0

Abstract

Double-Double (DD) is a novel laminate design concept that not only reduces design variables and simplifies the manufacturing process but also exhibits unique homogenization properties. While theory suggests that for any QuaDriaxial (QUAD or QD) laminate, DD can provide a corresponding laminate configuration with equivalent stiffness, the mechanical behavior of their Single-Lap Joint (SLJ) still requires further investigation. In this study, a DD SLJ equivalent to the quasi-isotropic QD SLJ commonly used in fuselage structures is designed by ensuring equivalence in the in-plane stiffness matrix. While the experimental results show nearly identical in-plane stiffness, the tensile strength of the DD SLJ is approximately 13 % higher than that of the Quad SLJ. Additionally, DD SLJ exhibit reduced out-of-plane deformation compared to Quad SLJ. Both theoretical and numerical analyses are conducted to elucidate the underlying mechanisms responsible for the superior mechanical behavior of DD SLJ. The findings indicate that the observed differences are primarily due to variations in bending stiffness, despite identical in-plane stiffness matrices. The results further demonstrate that the smaller bending deformation of DD laminates leads to reduced interfacial peeling forces, making DD SLJ less susceptible to failure. Finally, a comparison of different staggered ways of DD laminates indicated no significant differences in strength or stiffness. The study demonstrates that DD SLJ, designed with equivalent in-plane stiffness matrices, not only achieve the same tensile stiffness as QD SLJs but also exhibit higher strength. This highlights the great potential of DD laminates for application in the single-lap joints of aircraft structures.

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来源期刊

Thin-Walled Structures 工程技术-工程：土木

CiteScore

9.60

自引率

20.30%

发文量

801

审稿时长

66 days

期刊介绍： Thin-walled structures comprises an important and growing proportion of engineering construction with areas of application becoming increasingly diverse, ranging from aircraft, bridges, ships and oil rigs to storage vessels, industrial buildings and warehouses. Many factors, including cost and weight economy, new materials and processes and the growth of powerful methods of analysis have contributed to this growth, and led to the need for a journal which concentrates specifically on structures in which problems arise due to the thinness of the walls. This field includes cold– formed sections, plate and shell structures, reinforced plastics structures and aluminium structures, and is of importance in many branches of engineering. The primary criterion for consideration of papers in Thin–Walled Structures is that they must be concerned with thin–walled structures or the basic problems inherent in thin–walled structures. Provided this criterion is satisfied no restriction is placed on the type of construction, material or field of application. Papers on theory, experiment, design, etc., are published and it is expected that many papers will contain aspects of all three.