Linear Spring Model Reference

The Linear Spring model calculates contact between particles or between particles and a wall. The relationship between particle compression and contact forces is based on the relationship found in linear springs.

The model uses constants for normal and tangential spring stiffness that are either set by you directly or are based on properties of the particle: the radius, maximum overlap, and Young’s modulus (see Contact Force Modeling).


Theory	See Linear Spring Contact Model.
Provided By	[physics continuum] > Models > Multiphase Interaction > Phase Interactions > Phase Interaction [n] > Models > Optional Models
Example Node Path	Physics 1 > Models > Multiphase Interaction > Phase Interactions > Phase Interaction 1 > Models > Linear Spring
Requires	Optional Models: Lagrangian Multiphase Optional Models: Discrete Element Method (DEM) Multi-Phase Interactions: Multiphase Interaction selected automatically Under Multiphase Interaction, select Phase Interaction Topology: DEM Phase Interaction if it has not been automatically selected.
Properties	Static Friction Coefficient, Normal Restitution Coefficient, Tangential Restitution Coefficient. See Linear Spring Properties.
Activates	Physics Models	Optional Models and specifically the Rolling Resistance model
	Model Controls (child nodes)	Normal Spring Stiffness Method, Tangential Spring Stiffness Method

Linear Spring Properties

Static Friction Coefficient: The friction coefficient $C_{f s}$ . See Eqn. (3254).
Normal Restitution Coefficient: $C_{n r e s t}$ . See Eqn. (3257).
Tangential Restitution Coefficient: $C_{t r e s t}$ . See Eqn. (3258).

Normal Spring Stiffness Method

Specifies the method for assigning normal spring stiffness $K_{n}$ to the bodies in the interaction. See Eqn. (3251).

Constant: Stiffness is a constant set by the user.
Particle Material Based: Stiffness is calculated based on the material composing the particle and expressed in the Maximum Overlap/Radius Ratio property. See Particle Properties.

Tangential Spring Stiffness Method

Specifies the method for tangential normal spring stiffness $K_{t}$ to the bodies in the interaction. See Eqn. (3254).

Constant: Stiffness is a constant set by the user.
Particle Material Based: Stiffness is calculated based on the material composing the particle and expressed in the Maximum Overlap/Radius Ratio property. See Particle Properties.

Particle Properties

Maximum Overlap/Radius Ratio: A constant set by the user, based on the overlap distance and the particle radius. The default is 0.1.