Tensile effects in peridynamic plates with circular holes

Area of Science:

• Solid Mechanics
• Computational Materials Science
• Fracture Mechanics

Background:

• Microstructures significantly influence macroscopic mechanical behavior, including damage and fracture.
• Nonlocal theories incorporate microscale effects using an internal length scale, adept at handling discontinuities.
• Nonlocal models are valuable for analyzing damage onset and fracture propagation.

Purpose of the Study:

• To investigate the impact of nonlocal microstructure choices on fracture propagation in a classical problem.
• To analyze a plate with a circular hole under tension using nonlocal bond-based peridynamics.
• To evaluate a dimensionally reduced nonlocal model for computational efficiency.

Main Methods:

• Employed a recently proposed nonlocal dimensionally reduced model based on bond-based peridynamics.
• Analyzed a holed plate model with two distinct microstructures defined by the horizon parameter (internal length scale).
• Maintained consistent elastic stiffness, computed peridynamic stress, and used a stress-based bond failure criterion.

Main Results:

• Increasing the internal length scale shifts the stress peak further from the hole.
• A larger horizon leads to a more diffuse stress concentration area and a decreased stress concentration factor.
• The delamination surface development becomes more diffuse with a higher horizon value.

Conclusions:

• The internal length scale is a critical parameter in nonlocal fracture mechanics.
• Nonlocal models, particularly dimensionally reduced ones, offer insights into microstructure-dependent fracture behavior.
• The study demonstrates how varying microstructural parameters influences stress distribution and fracture patterns.