In situ strength analysis of cross‐ply composite laminates containing defects and interleaved woven layer using a computational micromechanics approach

Abstract

The transverse strength of 90° plies located in cross‐ply laminates subjected to transverse tension is investigated numerically. To reach this aim, it is assumed that the transverse cracking is formed by coalescence of fiber–matrix debonding, which propagates along the planes parallel to the fibers. The two‐dimensional finite element model (FEM) investigates the dominant micromechanical damage mechanisms, fiber–matrix debonding, and matrix cracking using the cohesive zone model (CZM) and plasticity, respectively. The numerical simulation is according to the extended computational micromechanics (ECMM) approach, which can be applied as a useful virtual test method instead of performing costly characterization tests. The results obtained from the present study show that the defects such as voids, imperfections, and residual stresses contribute to reducing the in situ strength of 90° plies. In the case of using an interleaved woven layer, the formation of the first transverse crack in unit cells within 90° layer is delayed.

Deep neural network aided cohesive zone parameter identifications through die shear test in electronic packaging

“…Energy damage evolution was used to define damage in terms of the energy required for failure (fracture energy) after the initiation of damage. The fracture energy G f for the simulation can be defined as the ratio of the integral area of the curve to the fracture area, 48–50 which is given as where A is the sintered area ( A = 3 mm × 3 mm). The viscous regularization method was used by setting an artificial viscosity coefficient to reduce the possibility of the convergence problem that may occur in the calculation.…”

“…Energy damage evolution was used to define damage in terms of the energy required for failure (fracture energy) after the initiation of damage. The fracture energy G f for the simulation can be defined as the ratio of the integral area of the curve to the fracture area, [48][49][50] which is given as…”

Theoretical and numerical investigation of mode‐I delamination of composite double‐cantilever beam with partially reinforced arms

“…The cohesive zone method is divided into bilinear cohesive model, trilinear cohesive model, exponential cohesive model, and so on according to the different traction and separation relationship. Due to its concise characteristics, bilinear and trilinear models have been widely used on both monotonic [22][23][24] and cyclic loading 25,26 on two or three-dimensional analysis and embedded in some finite element programs and softwares. The exponential cohesive model, which can be expressed by a single expression and a continuous curve, is closer to the constitutive of the material.…”