Barely visible impact damage in scaled composite laminates: Experiments and numerical simulations

Abstract

This paper investigates the effect of size and complexity of composite structures on the formation of low-velocity impact damage via experimental tests and numerical modelling. The ASTM standard low-velocity impact test and a scaled-up version of the test were conducted. A novel numerical technique is presented that combines 3D solid and thin 2D shell elements for modelling different domains to achieve a high level of fidelity locally under the impact location, whilst achieving good computational efficiency for large structures. Together with the experimental studies at the different scales, the predictive capability of the numerical models was systematically validated. This modelling method demonstrated an advanced computational efficiency without compromising predictive accuracy. The models are applied to a case study of low-velocity impact of a large-scale stringer-stiffened panel, showing this modelling approach to be suitable for predicating low-velocity impact damage and structural response of laminated composites over a range of sizes and complexities.

An integrated numerical model for investigating guided waves in impact-damaged composite laminates

“…There existed interconnections of matrix cracks, and interactions between matrix cracking and delamination, as investigated in [28]. A more detailed verification of the impact model can be found in [30,31] and is not repeated here. The considerations above support the validation of the predicted damage data.…”

“…Future work will focus on applying the methodology to more complex structures and to extend it to higher velocity impact, which will require the incorporation of a fibre failure criterion. [28,30]. …”

“…4a used a novel global-local approach developed by the authors in [30,31] to describe the laminate. The impact sensitive region with a 50 mm radius was modelled by 3D continuum (i.e.…”

Intra‐laminar toughening mechanisms to enhance impact damage tolerance of 2D woven composite laminates via yarn‐level fiber hybridization and fiber architecture

“…In general, low velocity and low energy blunt impacts are often considered a major issue in terms of postimpact damage tolerance. Out‐of‐plane low velocity blunt impact loading introduces considerable subsurface damage, which is often barely visible near the contact point on the surface, and subsequently leads to damage propagation and significantly affect the strength of damaged components (ie, postimpact residual strength) . A significant amount of research has been conducted over several decades to investigate the impact response of composite laminates using experimental, analytical, and computational approaches .…”

“…Out-ofplane low velocity blunt impact loading introduces considerable subsurface damage, which is often barely visible near the contact point on the surface, and subsequently leads to damage propagation and significantly affect the strength of damaged components (ie, postimpact residual strength). [6,7] A significant amount of research has been conducted over several decades to investigate the impact response of composite laminates using experimental, [8][9][10][11][12][13][14][15] analytical, [16][17][18][19][20][21] and computational approaches. [22][23][24][25] In this regard, enhancing postimpact damage tolerance, which is directly related to fracture toughness, and to achieve a balance between strength and toughness, which are in general mutually exclusive properties, [26] has been a key challenge to materials scientists and engineers.…”