Strain-rate and off-axis loading effects on the fibre compression strength of CFRP laminates: Experiments and constitutive modelling

Abstract

A series of dynamic longitudinal compression tests have been performed on cross-ply IM7/8552 specimens cut at different off-axis angles to produce different combinations of compression and shear stresses. Together with results from previous quasi-static tests of the same kind, quasi-static and dynamic fibre kinking failure envelopes have been obtained using classical laminate theory. This new experimental data has been compared against predictions from the leading fibre kinking theories, made rate-dependent by using rate-dependent in-plane shear properties, and show that, while they can accurately predict the effects of strain rate on the uniaxial compression strength, they are unable to capture the effects of shear, neither at quasi-static nor dynamic rates. Instead, a simpler more phenomenological approach is proposed to predict the rate-dependent fibre kinking strength of FRP laminates under multi-axial loads until the micromechanics can be more accurately described.

Determination of material properties of laminates of 15T and T3 tram faces

“…Another example of the utilisation of a dog-bone specimen but for a compression test was presented by Thomson [12] in 2020. The authors performed a series of static and dynamic longitudinal compression tests on a Split-Hopkinson pressure bar (SHPB).…”

Dynamic Biaxial Compression of CFRP Laminates Using Electromagnetic Loading

“…Carbon-fiber-reinforced polymer (CFRP) laminates have been widely employed in the aerospace industry, and their compressive behavior has been one of the major concerns during the design and analysis phase. Significant work has been done to find out the compressive failure mechanisms of CFRP composites under uniaxial stress [1][2][3][4][5]. The compressive failure of CFRP composites was systematically introduced by Budiansky and Fleck [1], and the compressive failure mode was found to be dominated by plastic kinking.…”

“…Different specimen designs and laminate configurations for compression tests have been evaluated by Thomson et al [4], and the cross-ply cuboidal specimens were recommended for testing the compressive strength of CFRP. Recently, Thomson et al [5] also successfully performed dynamic longitudinal compression tests on cross-ply specimens, and a simple phenomenological approach was proposed to predict the rate-dependent fiber kinking strength of CFRP. To explore the failure response of composites in a complex stress domain representing engineering applications, testing of composite samples under biaxial loading is highly desirable [6].…”

“…Xu and coworkers [15] conducted quasi-static biaxial compression tests on the 3D carbon/carbon composites, and the experimentally obtained failure stress points traced an elliptical path in the principal stress space, which could be well represented by the Tsai-Wu criterion. The results of these studies show that the mechanical behavior of composites depends strongly on the hydrostatic pressure [5,13,14,16]. Despite those reported studies on biaxial testing of composites in the quasi-static regime, the available biaxial testing systems are expensive and reliable results are not easy to obtain, and little work has been done on the biaxial failure of composites at high loading rates.…”

Механика Деформирования Тест-Образцов Из Слоистых Волокнистых Композитов Со Структурой [±45°] При Испытаниях На Растяжение И Сжатие 2. Исследование Плоских Внутренних Форм Потери Устойчивости

“…В рамках данного обзора невозможно охватить весь объём работ по этой тематике. В качестве примера можно отметить работы [10][11][12].…”