"Simulating Van der Waals interaction using Abaqus"
Van der Waals interactions occur between molecules due to temporary shifts in electron density, causing them to attract each other. This phenomenon can be crucial when the length scale of a structure is in the nano to micro meter range.
In the animation below, the Van der Waals interaction was implemented based on the Coarse-Grained Contact Model (CGCM) proposed by Sauer and Li in 2007. The CGCM assumes that the influential distance of the Van der Waals interaction is significantly smaller than the surface curvature, making it possible to derive the surface-to-surface potential from the Lennard-Jones potential (intermolecular potential). The model is valid as long as the surface curvature is more than 10 times larger than the influential distance, which applies to most finite element analysis (FEA) applications.
The CGCM was implemented with the UINTER (User Interaction) subroutine in Abaqus and validated with an analytical solution by Johnson-Kendall-Roberts (JKR). The force-displacement curve from the spherical indentation was predicted using the JKR model and compared with the Abaqus 2D axisymmetric model. The results show good agreement.
#Abaqus #SIMULIA #VanderWaals #MEMS #NEMS #Subroutine #FEA #FiniteElement #Simulation
References
[1] Gaffari R, Dong TX, Sauer RA, 2018, A new shell formulation for graphene structures based on existing ab-initio data, International Journal of Solids and Structures 135, 37-60.
[2] Sauer RA, Li S, 2007, An atomic interaction-based continuum model for adhesive contact mechanics, Finite Elements in Analysis and Design 43, 384-396.
[3] Sauer RA, Wriggers P, 2009, Formulation and analysis of a three-dimensional finite element implementation for adhesive contact at the nanoscale, Computer Methods in Applied Mechanics and Engineering 198, 3871-3883.
Van der Waals interactions occur between molecules due to temporary shifts in electron density, causing them to attract each other. This phenomenon can be crucial when the length scale of a structure is in the nano to micro meter range.
In the animation below, the Van der Waals interaction was implemented based on the Coarse-Grained Contact Model (CGCM) proposed by Sauer and Li in 2007. The CGCM assumes that the influential distance of the Van der Waals interaction is significantly smaller than the surface curvature, making it possible to derive the surface-to-surface potential from the Lennard-Jones potential (intermolecular potential). The model is valid as long as the surface curvature is more than 10 times larger than the influential distance, which applies to most finite element analysis (FEA) applications.
The CGCM was implemented with the UINTER (User Interaction) subroutine in Abaqus and validated with an analytical solution by Johnson-Kendall-Roberts (JKR). The force-displacement curve from the spherical indentation was predicted using the JKR model and compared with the Abaqus 2D axisymmetric model. The results show good agreement.
#Abaqus #SIMULIA #VanderWaals #MEMS #NEMS #Subroutine #FEA #FiniteElement #Simulation
References
[1] Gaffari R, Dong TX, Sauer RA, 2018, A new shell formulation for graphene structures based on existing ab-initio data, International Journal of Solids and Structures 135, 37-60.
[2] Sauer RA, Li S, 2007, An atomic interaction-based continuum model for adhesive contact mechanics, Finite Elements in Analysis and Design 43, 384-396.
[3] Sauer RA, Wriggers P, 2009, Formulation and analysis of a three-dimensional finite element implementation for adhesive contact at the nanoscale, Computer Methods in Applied Mechanics and Engineering 198, 3871-3883.