A stiffness degradation model for cracked multidirectional laminates with cracks in multiple layers. (April 2015)

• Record Type: Journal Article
• Authors: Carraro, P.A.; Quaresimin, M.
• Is Part Of: International journal of solids and structures. Volume 58(2016)
• Page Start: 34
• Page End: 51
• Publication Date: 2015-04
• Subjects: Analytical solutions -- Composite materials -- Laminate -- Shear lag -- Stiffness; Mechanics, Applied -- Periodicals; Structural analysis (Engineering) -- Periodicals; Elastic solids -- Periodicals; Mécanique appliquée -- Périodiques; Constructions, Théorie des -- Périodiques; Solides élastiques -- Périodiques; Elastic solids; Mechanics, Applied; Structural analysis (Engineering); Periodicals; 624.18
• DOI: 10.1016/j.ijsolstr.2014.12.016
• Languages: English
• ISSNs: 0020-7683

Abstract

Highlights: Modelling stiffness degradation of composite laminates with off-axis cracks is essential in design. Two models, based on an "optimal" shear lag analysis and the principle of superposition, are developed. Models are fully analytical and valid for any lay-up and number of layers. Interaction of cracks in multiple layers is accounted for. Estimations of stiffness degradation are in good agreement with experimental data from the literature. Abstract: In the present work the problem of the stiffness degradation of multidirectional symmetric laminates in the presence of off-axis cracks is studied. A new analytical model is presented, capable of estimating the elastic properties of a multidirectional symmetric laminate with an arbitrary lay-up and cracks in one or more plies. The model is based on the so called "optimal" shear lag analysis of a laminate with cracks in one layer (and its symmetric), coupled with an analytical procedure to account for the presence of cracks in multiple plies, considering also their mutual interaction. The model requires, as inputs, the geometric and elastic properties of the layers and the crack density only. A very satisfactory agreement is found between the present predictions and experimental and numerical results from the literature. It is also shown that accounting for the mutual interaction between cracks in different plies is fundamental for a reliable estimation of the stiffness drop.