Predicting the effect of stitching on the mechanical properties and damage of non-crimp fabric composites: finite element analysis

Contributions of Stepan V Lomov to the research and development of composite materials

“…These studies created a gallery of options which can be selected for any problem depending on the expected precision, allowable computational expenses, and objectives of modelling. 76 Tools developed for generating FE models allowed to systematically explore a wide range of various textile composites based on 2 D woven laminates, 68,77–86 3 D woven fabrics, 74,87 braided textiles, 66,88 non-crimp fabrics, 89–91 structurally stitched preforms, 72,92 etc. Importantly, most of these models were validated against extensive experimental characterizations.…”

“…as in the instance of non-crimp fabric composites. 89 The cases when a characteristic crack exceeds the unit cell size are challenging and require striking a balance between the expected precision and a rational assessment of the textile composite performance. 64…”

“…[103][104][105][106][107] Damage occurring at early stages may also invalidate the periodic assumptions. 89 Draping and forming operations of a textile over a complex tool breaks the periodicity and requires pragmatic approaches to dealing with multi-scale modelling. 77,108 Different approaches were put forward to describe and solve these problems.…”

“…Characteristic to his research philosophy, a breadth of various damage models has been applied and assessed against highfidelity experimental data. This included the element discount method (where selected stiffness components are locally reduced when a failure criterion is triggered), 66,67,72,82,83,85,90 continuous damage mechanics where damage evolution laws are prescribed to a volume within unit cell, 64,65,89,143 direct modelling of crack propagation using mesh refinement, 91 modelling cracking using a coupled cohesive and embedded elements approach, 144 and even including elements of damage modelling into boundary conditions. 64 Exploring each of the options was accompanied by systematic examination of the limitations and sometimes paradoxes of implementation.…”

Estimation of Lamina Stiffness and Strength of Quadriaxial Non-Crimp Fabric Composites Based on Semi-Laminar Considerations

“…Mikhaluk et al [16] used acoustic emission (AE) registration and X-ray imaging to detect damage initiation and evolution in quadriaxial laminates under tensile load, and the numerical simulation of the failure process was also carried out. Ivanov et al [17] summarized the previous meso-scale model, and set up a meso-scale mechanically representative volume (mRVE), and predicted the effect of stitching on the mechanical properties of non-crimp fabric composite, such as, stiffness, failure initiation, stiffness degradation and strength. The current researches were focused on the performance of a whole continuous plies QNCF layer or laminate, but few studies has been done on the lamina mechanical properties of the materials.…”