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This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). The effect of the interface stiffness and interface strength on the low-velocity impact response of woven-fabric semicylindrical composite shells is studied using finite element (FE) models generated with continuum shell elements and cohesive surfaces. The intralaminar damage is accounted for using the constitutive model provided within the ABAQUS software, while the interlaminar is addressed utilising cohesive surfaces. The results show that the interface stiffness has a negligible effect on the force and energy histories for values between 101 N/mm3 and 2.43 × 106 N/mm3 . However, it has a significant impact on the delamination predictions. It is observed that only the normal interface strength affects the maximum impact force and the delamination predictions. Increasing its value from 15 MPa to 30 MPa resulted in an 8% growth in the maximum force, and a substantial reduction in the delaminated area. The obtained results serve as guidelines for the accurate and efficient computation of delamination. The successful validation of the FE models establishes a solid foundation for further numerical investigations and offers the potential to significantly reduce the time and expenses associated with experimental testing.

This paper presents an efficient and reliable approach to study the low-velocity impact response of woven composite shells using 3D finite element models that account for the physical intralaminar and interlaminar progressive damage. The authors’ previous work on the experimental assessment of the effect of thickness on the impact response of semicylindrical composite laminated shells served as the basis for this paper. Therefore, the finite element models were put to the test in comparison to the experimental findings. A good agreement was obtained between the numerical predictions and experimental data for the load and energy histories as well as for the maximum impact load, maximum displacement, and contact time. The use of the mass-scaling technique was successfully implemented, reducing considerably the computing cost of the solutions. The maximum load, maximum displacement, and contact time are negligibly affected by the choice of finite element mesh discretization. However, it has an impact on the initiation and progression of interlaminar damage. Therefore, to accurately compute delamination, its correct definition is of upmost importance. The validation of these finite element models opens the possibility for further numerical studies on of woven composite shells and enables shortening the time and expenses associated with the experimental testing. Fundação para a Ciência e a Tecnologia UIDB/00285/2020 LA/P/0112/2020.

Nowadays, composite materials are increasingly used in the most diverse areas of engineering, where non-planar geometries begin to be quite frequent. However, the existing knowledge about its mechanical performance is still not enough for structural applications. Therefore, experimental tests were carried out to study the thickness effect on static compression and multi-impact response of laminated E-glass/Polyester semicylindrical shells. For this purpose, specimen with thicknesses of 1.1 mm, 1.6 mm and 2.1 mm (corresponding to 6, 9 and 12 woven fabric layers) were considered. In terms of static response, higher thicknesses are responsible for higher compressive strength and stiffness, reaching, in the first case, differences of 252.6 % between the thinnest and thickest shells. Regarding the multi-impact response, the impact fatigue life increases 17.4 times for the analysed thickness range, which can be explained by the different damage mechanisms observed. It was observed that impact damage becomes more localized with increasing thickness, because the energy is dissipated by more interfaces.