# EEPA Model Properties

The properties of the Edinburgh-Elasto-Plastic-Adhesive (EEPA) Contact Model model are shown below for reference. See the properties table in the EEPA “Properties” section for full details for each property.

Note

Read-only properties are indicated by (r) at right in this listing.

eepa

$$\chi$$ - adhesive branch exponent with default value 1.5.

dp_force v (r)

$$\mathbf{F^{d}}$$ - dashpot force. Expressed in the contact plane coordinate system.

dp_mode i

$$M_d$$ - dashpot mode with default value 0.

dp_nratio f

$$\beta_n$$- normal critical damping ratio with default value 0.0.

dp_sratio f

$$\beta_s$$ - shear critical damping ratio with default value 0.0.

eepa_force v

$$\mathbf{F^{EEPA}}$$ - EEPA force with default value $$\mathbf{0}$$. Expressed in the contact plane coordinate system.

eepa_poiss f

$$\nu$$ - poisson’s ratio with default value 0.0.

eepa_shear f

$$G$$ - shear modulus in units of stress with default value 0.0.

eepa_slip b (r)

$$s$$ - sliding slip state.

force_min f

$$f_{min}$$ - minimum force with default value 1.5.

fric f

$$\mu$$ - sliding friction coefficient with default value 0.0.

ks_fac f

$$k_{sf}$$ - shear stiffness scaling factor with default value 1.0.

lu_exp f

$$m$$ - loading-unloading branch exponent with default value 1.5.

overlap_max f (r)

$$\delta_{max}$$ - maximum overlap.

plas_ratio f (r)

$$\lambda_p$$ - plasticity ratio with default value 0.5.

pull_off f (r)
$$F^0$$ - pull-off force.
rgap f

$$g_r$$ - reference gap in units length with default value 0.0.

rr_fric f

$$\mu_r$$ - rolling friction coefficient with default value 0.0.

rr_moment v

$$\mathbf{M^r}$$ - Rolling resistance moment with default value $$\mathbf{0}$$. Expressed in the contact plane coordinate system.

rr_slip b (r)

$$s_r$$ - rolling slip state.

$$\gamma^*$$ - Effective surface adhesion energy with default value 0.0.