A Bridge Between the Micro- and Mesomechanics of Laminates: Fantasy or Reality?

A micromechanics-based interface mesomodel for virtual testing of laminated composites

“…The first two mechanisms have been studied for laminated composites by the micromechanics community (see the reviews [1,[21][22][23]). Matrix microcracking (Scenario 1) is driven by the ply's microstructure: usually, matrix microcracks originate perpendicular to the plane of the ply, then run throughout the ply's thickness, and finally grow parallel to the fibers' direction.…”

“…As they occur at the fiber's scale, they can be homogenized and they are introduced directly through damage variables and evolution laws at the ply's scale. In order to handle these mechanisms, a computational micromodel was introduced in [1,23] and developed in [24,29]. This micromodel reproduces the key points observed in the micromechanics of laminates [1,23] quite well.…”

“…One has: σ 13 = cos ασ 13 − sin ασ 23 , σ 23 = sin ασ 13 + cos ασ 23 σ 1 3 = cos ασ 13 + sin ασ 23 , σ 2 3 = − sin ασ 13 + cos ασ 23 (10)…”

“…Both transverse intraply cracks and delamination cracks are described in detail; thus, the competition between the two mechanisms can be modeled directly. Indeed, the physics of the problem is very well-known (see the review papers [1,[21][22][23]). Today, the difficulty lies elsewhere, namely in the fact that the discrete modeling of every single discontinuity becomes unfeasible for complex engineering problems involving several thousands of cracks.…”

“…Today, the difficulty lies elsewhere, namely in the fact that the discrete modeling of every single discontinuity becomes unfeasible for complex engineering problems involving several thousands of cracks. On the one hand, even with high-performance computational tools [24], the computational micromechanical model introduced in [1,23,25] still leads to prohibitive computational efforts and, thus, is far from meeting the virtual structural testing requirements. On the other hand, when a mesoscale damage approach is used, some of the information regarding the detailed microscopic stress/strain state is lost.…”