Measurement of Delamination Fracture Energy Using Stepped Laminates

Stress intensity factors as the fracture parameters for delamination crack growth in composite laminates

A ``mutual integral'' approach is used to calculate the mixed-mode stress intensity factors for a free-edge delamination crack in a laminate under tensile loading conditions. This ``mutual integral'' approach, for generalized plane strain conditions, is based on the application of the path-independent J integral to a linear combination of three solutions: one, the problem of the laminate to be ...

Mode II delamination toughness of z-pinned laminates

Mode II delamination toughness of z-pin reinforced composite laminates is investigated using finite element (FE) method. The z-pin pullout process is simulated by the deformation and breakage of non-linear springs. A critical shear stress criterion based on linear elastic fracture mechanics is used to simulate crack growth in an end-notched-flexure (ENF) beam made of z-pinned laminates. The mod...

Vibration Monitoring of Composite Laminates with Delamination Damage

Measurement of Variation in Fracture Strength and Calculation of Stress Concentration Factor in Composite Laminates with Circular Hole

In this research, residual strength and stress concentration factor of laminated composites with a circular open hole are studied analytically, numerically and experimentally. The numerical study was carried out using the finite element method. Moreover an analytical study was carried out with developing of point stress criterion. Mechanical testing was performed to determine the un-notched ten...

MULTI FRACTURE/DELAMINATION ANALYSIS OF COMPOSITES SUBJECTED TO IMPACT LOADINGS

A combined finite/ discrete element method is presented for modelling of composite specimens subjected to dynamic/impact loadings. The main task is set on developing an algorithm for simulation of potential bonding and debonding/delamination phenomena during impact or general dynamic loading conditions. In addition, full fracture analysis can also be performed. The proposed approach adopts a ge...