A Three-Dimensional Equivalent Stiffness Model of Composite Laminates with Wrinkle Defects

Area of Science:

• Materials Science
• Mechanical Engineering
• Composite Materials

Background:

• Wrinkle defects significantly impact the stiffness of composite laminates.
• Accurate prediction of mechanical properties in defective composites is crucial for structural integrity.

Purpose of the Study:

• To develop an effective analytical model for predicting the 3D equivalent elastic properties of composite laminates with wrinkle defects.
• To investigate the influence of wrinkle parameters and stacking sequences on laminate stiffness.

Main Methods:

• Established a geometric model based on wrinkle defect microstructure.
• Utilized classical laminate theory and homogenization to derive constitutive equations and flexibility matrices for wrinkled regions.
• Derived equivalent stiffness parameters for various laminate configurations.

Main Results:

• The analytical model accurately predicts the stiffness of composite laminates affected by wrinkles.
• Out-of-plane and in-plane wrinkle angles were identified as key factors influencing mechanical properties.
• The model's accuracy was validated against numerical and other theoretical models.

Conclusions:

• The proposed analytical model is efficient, requires few parameters, and accurately predicts the stiffness of composite structures with wrinkles.
• The model serves as a valuable tool for quantitative analysis and understanding the mechanical response of defective laminates.