Abstract

Fiber-reinforced composites offer lightweight, high-strength and high-stiffness solutions for many structural applications. The trend of increasing composites use is anticipated to continue well into the future as the drive for sustainable solutions gains urgency. However, due to their anisotropic and laminated nature, the fracture and damage mechanisms of such structures are coupled and complex. The prediction of structural performance of composite structures is critical to their design and optimization of material usage. This requires understanding of the interaction and evolution of damage mechanisms and their accurate modeling in computational analysis, often at multi-scale levels. Recently, advanced and innovative computational methods have been devised to improve failure prediction based on underlying mechanics and progressive damage observations. This lecture will overview the advantages of some recent discrete crack approaches [1,2] for composites as well as high-fidelity methods such as an adaptive discrete-smeared crack (A-DiSC) method [3] that could point the way to model impact damage and failure of large composite structures. Innovative finite element squared (FE2) methods [4] have potential to solve multi-scale fracture and damage problems in composites by directly incorporating failure mechanisms at the micromechanics levels and enable efficient structural modeling of complex 3D-printed structures. A brief overview of the research activities of the composites materials and structures group at the Dept of Mechanical Engineering, National University of Singapore, will also be included in the presentation.

References

[1] J. Zhi, T.E. Tay, Explicit modelling of matrix cracking and delamination in laminated composites with discontinuous solid-shell elements, Computer Methods in Applied Mechanics and Engineering, v.351, 60-84 (2019)

[2] X. Lu, B.Y. Chen, V.B.C. Tan, T.E. Tay, A separable cohesive element for modelling coupled failure in laminated composite materials, Composites Part A: Applied Science & Manufacturing, v.107, 387-398 (2018)

[3] X. Lu, M. Ridha, V.B.C. Tan, T.E. Tay, Adaptive discrete-smeared crack (A-DiSC) model for multi-scale progressive damage in composites, Composites Part A: Applied Science & Manufacturing, v.125, 1-16 (2019)

[4] V.B.C. Tan, K. Raju, H.P. Lee, Direct FE2 for concurrent multilevel modeling of heterogeneous structures, Computer Methods in Applied Mechanics and Engineering, (accepted, 2019)