Dynamic Compressive Behavior, Constitutive Modeling, and Complete Failure Criterion of 30 Vol.% B₄C/2024Al Composite

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Mechanics

Background:

• Boron carbide (B4C)/aluminum (Al) composites are advanced materials with significant engineering applications.
• Understanding their behavior under dynamic loading and varying temperatures is critical for performance prediction.
• Existing models may not fully capture the complex deformation and failure mechanisms in these composites.

Purpose of the Study:

• To investigate the compressive behavior of B4C/Al composites under quasi-static and dynamic loading.
• To develop and validate a modified Johnson-Cook (JC) model with a complete failure criterion for these composites.
• To analyze the underlying mechanisms of yield strength enhancement and material failure.

Main Methods:

• Experimental investigation of B4C/Al composites under various loading conditions and temperatures.
• Modification of the JC model and development of a failure criterion.
• Finite element analysis (FEA) using Abaqus with a user subroutine (VUHARD) incorporating the modified JC (MJC) model and failure criterion.
• Microstructural analysis to identify failure mechanisms.

Main Results:

• Strain softening was observed in the stress-strain curves of the composites.
• Taylor and load transfer mechanisms significantly contributed to yield strength enhancement (89.6%).
• Particle fracture and matrix damage were primary failure mechanisms, with microcracks propagating through the matrix, interface, or particles.
• The MJC model achieved high accuracy (MAE < 15%) in predicting plastic deformation under dynamic loading.
• FEA simulations accurately captured plastic deformation and crack propagation.

Conclusions:

• The modified Johnson-Cook model and failure criterion provide an accurate representation of B4C/Al composite behavior under dynamic loading.
• The study elucidates key mechanisms governing yield strength and failure in these composites.
• This work offers a valuable computational tool for predicting the performance of ceramic-reinforced aluminum matrix composites.