IMPACT

 

The IMPACT function returns the contact force in a contact model defined by the relative location and velocity of two markers.

 

Format

 

Arguments definition

Distance()

The expression for the relative distance between the two markers on the contacting entities

Velocity()

The expression for the relative velocity between the two markers on the contacting entities

Free length()

The contact distance between the two markers on the contacting entities

     This must be a real number or a function that returns a real number.

     The free length(x1) determines whether or not contact is made.

Stiffness()

The modulus rigidity on the spring force

Stiffness exponent()

The nonlinear coefficient value on the surface of the spring force

Damping()

The maximum damping coefficient for the calculation of the damping force

Penetration()

The depth at which the damping coefficient reaches 0

 

Formulation

 

Example

Figure 1  Example modeling for the IMPACT function

 

IMPACT(DY(Body2.Marker1,Body1.Marker2,Body1.Marker2),VY(Body2.Marker1,Body1.Marker2,Body1.Marker2),100,1000,1.3,10,2)

     x = DY: Distance variable

     img25.gif = VY: The time derivative of y

     x1 = 0.0: Free length of y

     k =1000: Stiffness

     exp = 1.3: Exponent of the force

     cmax = 10: Maximum damping coefficient

     d = 2: Boundary penetration

Figure 2  Scope result using the IMPACT function