Progressive Damage Modelling of Composite Materials

Ibrahim, Ghalib Rzayyig (2023) Progressive Damage Modelling of Composite Materials. Doctoral thesis (PhD), Manchester Metropolitan University.

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Abstract

The effects of thermal load combined with mechanical loading of composite laminates are analysed. A new incremental damage evolution law of the cohesive zone model has been developed that can take into account the effects of change in temperature of an interface element. The numerical model results for both test specimens were in good agreement with the data available in the literature. The second goal of this work was to investigate a cohesive zone model under fatigue loading. A new damage evaluation law and a new evaluation rate of fatigue damage for each cyclic loading (∂D⁄∂N) have been presented. Single Lap Joint (SLJ) Model and Double Cantilever Beam (DCB) specimens were used to validate a proposed approach. The results confirmed that the maximum difference between numerical and experimental when using a DCB specimen was 5% at 250 cycles. Whereas the difference between the numerical results and experimental when using a SLJ was 5.2% at 2000 cycles and 4.6 % at 4000 cycles. Finally, the new damage evolution law for matrix cracking and fibre damage is presented and investigated. The results obtained using the new damage evolution law were in good agreement with experimental results showing that the model presented has the ability to overcome convergence problems in numerical simulations.