TY - JOUR

T1 - Dynamic fracture investigation of concrete by a rate-dependent explicit phase field model integrating viscoelasticity and micro-viscosity

AU - Hai, Lu

AU - Wriggers, Peter

AU - Huang, Yu jie

AU - Zhang, Hui

AU - Xu, Shi lang

N1 - Funding Information: The authors would acknowledge the financial supports from National Natural Science Foundation of China ( 52208296 ), Fundamental Research Program of Shanxi Province ( 202203021212132 and 202203021212142 ) and “ Overseas Training Program for Young Talents ” of Ocean University of China. The author Peter Wriggers gratefully acknowledges support for this research by the “German Research Foundation” (DFG) in the PRIORITY PROGRAM SPP 2020, project WR 19/58-2.

PY - 2024/1/1

Y1 - 2024/1/1

N2 - To investigate dynamic fracture mechanisms of quasi-brittle materials, this work proposes a rate-dependent phase field model that integrates both macroscopic viscoelasticity and micro-viscosity to reflect the rate effects by free water and unhydrated inclusions. Based on the unified phase field theory, the model introduces a linear viscoelastic constitutive relation in effective stress space to consider the macro-viscosity of the bulk material. Additionally, the micro-force balance concept is utilized with the micro-viscosity to derive a parabolic phase field evolution law that accurately describes the dynamic micro-crack development. Explicit numerical solution schemes are established for the governing equations by developing VUEL and VUMAT subroutines in ABAQUS. This eliminates the convergence issue in implicit phase field modelling. Four typical benchmarks are investigated to validate the proposed model for macroscale and mesoscale heterogeneous problems. It is found that the proposed model can well capture the crack branching, delaying characteristic of micro-crack growth, and increase of macroscopic strength under higher strain rates. Using real meso‑structures from CT images, the complicated dynamic behaviour of concrete is investigated which yields deeper insight into stress wave propagation, crack evolution and load-carrying capacities.

AB - To investigate dynamic fracture mechanisms of quasi-brittle materials, this work proposes a rate-dependent phase field model that integrates both macroscopic viscoelasticity and micro-viscosity to reflect the rate effects by free water and unhydrated inclusions. Based on the unified phase field theory, the model introduces a linear viscoelastic constitutive relation in effective stress space to consider the macro-viscosity of the bulk material. Additionally, the micro-force balance concept is utilized with the micro-viscosity to derive a parabolic phase field evolution law that accurately describes the dynamic micro-crack development. Explicit numerical solution schemes are established for the governing equations by developing VUEL and VUMAT subroutines in ABAQUS. This eliminates the convergence issue in implicit phase field modelling. Four typical benchmarks are investigated to validate the proposed model for macroscale and mesoscale heterogeneous problems. It is found that the proposed model can well capture the crack branching, delaying characteristic of micro-crack growth, and increase of macroscopic strength under higher strain rates. Using real meso‑structures from CT images, the complicated dynamic behaviour of concrete is investigated which yields deeper insight into stress wave propagation, crack evolution and load-carrying capacities.

KW - Dynamic fracture mechanisms

KW - Mesoscale concrete

KW - Quasi-brittle materials

KW - Rate dependence

KW - Unified phase field theory

UR - http://www.scopus.com/inward/record.url?scp=85174437333&partnerID=8YFLogxK

U2 - 10.1016/j.cma.2023.116540

DO - 10.1016/j.cma.2023.116540

M3 - Article

AN - SCOPUS:85174437333

VL - 418

JO - Computer Methods in Applied Mechanics and Engineering

JF - Computer Methods in Applied Mechanics and Engineering

SN - 0045-7825

M1 - 116540

ER -