Linear-Nonlinear Stiffness Responses of Carbon Fiber-Reinforced Polymer Composite Materials and Structures: A...

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Mechanics

Background:

• Stiffness response (load-deformation behavior) is crucial for validating computational models against experimental data.
• Carbon Fiber-Reinforced Polymers (CFRPs) are advanced materials requiring accurate mechanical behavior prediction.
• Understanding stiffness dependency on material and structural parameters is key for reliable engineering applications.

Purpose of the Study:

• To numerically investigate the linear and nonlinear stiffness behavior of CFRP composites.
• To analyze the influence of elastic and damage model parameters on stiffness at material and structural levels.
• To determine the impact of structural configuration and geometry on the overall stiffness response.

Main Methods:

• Development of a finite element model incorporating a validated constitutive damage model.
• Simulation of elastic, yielding, and damage evolution processes.
• Examination of stiffness responses for a unidirectional laminate and three multidirectional composite structures under different loading conditions.

Main Results:

• Material-level stiffness in CFRP composites is directly dependent on elastic properties.
• Structural-level stiffness is influenced by a combination of material properties, structural configuration, geometry, and lay-up.
• Maximum reaction forces, displacements, and nonlinear responses are highly sensitive to both mechanical properties and structural design.

Conclusions:

• Accurate prediction of CFRP composite stiffness requires consideration of both material characteristics and structural design factors.
• The study provides insights into parameter dependencies for enhancing the fidelity of computational models for composite structures.
• This research aids in the development of more reliable mathematical-physical models for engineering applications involving CFRP composites.