Sweeping process approach to stress analysis in elastoplastic lattice spring models with applications to network...

Area of Science:

• Materials Science
• Computational Mechanics
• Nonlinear Dynamics

Background:

• Disordered network materials are prevalent but their nonlinear mechanical behaviors are difficult to analyze.
• Existing models often struggle to capture the complex interplay of elasticity and plasticity in these systems.

Purpose of the Study:

• To connect Moreau's sweeping process framework to lattice spring models with plasticity.
• To develop a computational method for analyzing quasistatic evolution and stresses in elastic-perfectly plastic lattices.
• To investigate the mechanical properties of hyperuniform disordered network materials.

Main Methods:

• Derived equations for quasistatic evolution of elastic-perfectly plastic lattices.
• Constructed a sweeping process and numerical schemes, including an efficient 'leapfrog' computational framework.
• Analyzed elastoplastic stresses in hyperuniform disordered network materials.

Main Results:

• The 'leapfrog' framework rigorously tracks plastic events based on sweeping process theory.
• Hyperuniform disordered network materials show enhanced mechanical properties.
• Increasing hyperuniformity correlates with increased stiffness, yield strength, and tensile strength.

Conclusions:

• The developed sweeping process framework provides a robust method for analyzing nonlinear mechanical behaviors in disordered materials.
• Hyperuniformity is a key design principle for enhancing mechanical performance in network materials.
• The event-based framework is generalizable to other heterogeneous material systems.