Combined loadings after medium velocity impact on large CFRP laminate plates: Tests and enhanced computation/testing dialogue

Abstract

The development and certification of aeronautical composite structures is still largely based on the pyramid of tests. This approach is extremely costly in terms of number of tests, especially at the level of coupons. Moreover, these tests are highly conservative, under uniaxial loading, and do not represent the actual behavior at structure scale. To overcome these drawbacks, a new methodology has been developed at the Institut Cl� ement Ader, which uses a complex loading test rig for technological specimens. This research focuses on the combined loading after impact of CFRP plates and highlights a specific behavior quite different from the usual CAI (Compression After Impact) response at the scale of coupons. In particular, compression, shear and combined shear/compression loadings were applied to large Carbon Fiber Reinforced Plastics (CFRP) laminated plates and the interaction of the impact damage with the post-buckling behavior has been investigated.

Experimental and Numerical Analysis of Low-Velocity Impact of Carbon Fibre-Based Non-Crimp Fabric Reinforced Thermoplastic Composites

“…Currently, the available data and information in the literature with respect to the low-velocity impact (LVI) performance of carbon fibre reinforced thermoplastic polymer (CFRTP) is still limited, unlike carbon fibre reinforced thermosetting (CFRTS) composites [1,[10][11][12][13][14][15][16][17][18]. In fact, in the literature, much research has focused solely on glass fibre reinforced polymer (GFRP) [19].…”

“…Trellu et al [10] have previously reported the compression after impact (CAI) performance of unidirectional (UD) CFRTS (T700/M21 epoxy) at velocities ranging from 54 m/s to 110 m/s. This represents a small debris impact during aircraft take-off or landing.…”

Local buckling on large sandwich panels used in light aviation: Experimental setup and failure scenarios

“…To capture the failure scenario, the test bench was equipped with several measurement systems as shown in Figure 9. Stereo Digital Image Correlation (SDIC) is a very reliable method that has already been used on previous VERTEX tests [24][25] [34]. Moreover, SDIC can measure out-of-plane displacements and reconstruct a 3D shape evolution.…”

“…Serra studied the failure of carbon fibre reinforced polymer notched plates [25] [33]. Trellu studied the effect of low-velocity impacts on carbon fibre reinforced polymer plates under multiaxial loading [34].…”

Experimental behaviour of aeronautical notched carbon fibre reinforced thermoplastic panels under combined tension-shear-pressure loadings

“…Serra et al [42] presented the machine and the state of the art for this kind of intermediate multi-axial test rigs. Large notch behaviour [43] and residual strengths post impact [44] have been assessed for planar samples under combined loadings. This is a first step towards moving up one level of the test pyramid with stiffened samples to finally assess large damage behaviour phenomenology, representative of current fuselage sections, at moderate cost.…”