Influence of Failure Criteria and Intralaminar Damage Progression Numerical Models on the Prediction of the Mechanical Behavior of Composite Laminates

Abstract

This work evaluates the effectiveness of commonly adopted local damage evolution methods and failure criteria in finite element analysis for the simulation of intralaminar damage propagation in composites under static loading conditions. The proposed numerical model is based on a User Defined Material subroutine (USERMAT) implemented in Ansys. This model is used to predict the evolution of damage within each specific lamina of a composite laminate by introducing both sudden and gradual degradation rules. The main purpose of the simulations is to quantitatively assess the influence of the adopted failure criteria in conjunction with degradation laws on the accuracy of the numerical predictions in terms of damage evolution and failure load. The mechanical behavior of an open hole tension specimen and of a notched stiffened composite panel under shear loading conditions have been numerically simulated by Progressive Damage Models (PDM). Different failure criteria have been implemented in the developed Ansys USERMAT, together with sudden and gradual degradation rules based on the Continuum Damage Mechanics (CDM) approach. Numerical results have been validated against experimental data to assess the effects of the different failure criteria and damage evolution law on the global mechanical response and local damage predictions in composite laminates.

On the Crashworthiness Behaviour of Innovative Sandwich Shock Absorbers

“… Segment OA of Figure 1 , represents the linear mechanical behaviour up to the damage onset threshold (point A) while the damage evolution up to the complete failure (point C) is expressed by the AC segment. The onset loading value for the different composites’ failure modes can be calculated, by means of the Hashin failure indices [ 20 , 21 , 22 , 23 , 24 ]. Their mathematical expression is given in the Equations (A8)–(A11) where: F ft , F fc , F mt , and F mc , called “ Hashin’s critical values” , are, respectively, the values of the criterion associated to the fibre tensile, fibre compressive, matrix tensile, and matrix compressive failure mode.…”

“…To simulate the degradation in the finite element, a gradually reduction of the material stiffness in the evolution phase is introduced. It can be calculated using Equation (A12): In this equation, K represent the material stiffness in the undamaged condition while d i is a damage coefficient [ 23 ], which can be expressed, for each failure mode, according to Equation (A13). where is the equivalent displacement for an applied strain referred to a characteristic finite element length L C , is the initial equivalent displacement at which the considered failure criteria is met, and is the displacement at which the material is completely damaged.…”

Progressive damage behavior of composite L‐stiffened structures with initial delamination defects under uniaxial compression: Experimental and numerical investigations

“…[25][26][27] Riccio et al 28 evaluated the state of bonding stresses within the bonded joints in repaired composite structures using a progressive damage method based on ABAQUS. Aniello Riccio et al 29 performed numerical simulations of open-hole tensile specimens using the Hashin and Puck criteria to quantitatively assess the influence of the failure criteria used and the degradation law on the damage evolution and the accuracy of the failure load.…”

FEM-Validated Optimal Design of Laminate Process Parameters Based on Improved Genetic Algorithm

“…Carbon fibre reinforced composite materials (CFRP) are widely used in the fields of aviation equipment structures [1], fuselages and wings manufacturing due to their high corrosion resistance, high strength and lightweight [2,3]. As a typical representative of the practical application of composite materials, laminates have a direct impact on the mechanical properties of CFRPs, which depend highly on their laying angle and laying sequence.…”

“…This comparison validates the IGA and the optimal results can provide a reference for engineering design. Let stress ∅ be a function of x, y, the following relationship holds: The expressions of σ x , σ y , τ xy from (A7) as below 1 Since σ y is caused by the constant shear force q, and its value does not depend on x, it is a function of y. Therefore, we can set σ y = f (y)…”