Contact Page

 

This page defines characteristic values to contact between two geometry entities. Sprocket, Single Wheel, and Double Wheel supported in RecurDyn are using this page.

 

Figure 1  Sprocket property page [Contact page]

 

Contact normal force

The contact normal force is obtained by

img30.gif

 

where, k and c are the stiffness and damping coefficients which are determined by an experimental method, respectively. Defining_contact_parameters_htm_eqn13 and img31.gif are a penetration and time differentiation of the penetration, respectively. The exponents Defining_contact_parameters_htm_eqn14 and Defining_contact_parameters_htm_eqn15  generates a non-linear contact force and the exponent Defining_contact_parameters_htm_eqn16 yields an indentation damping effect.

 

     Characteristic: Defines the contact properties such as the stiffness coefficient, damping coefficient, and friction coefficients. Also, these coefficients can be given as user-defined spline curves.

 

    Stiffness Coefficient: Specifies a stiffness coefficient for the contact normal force.

    Stiffness Spline: The spline shows the contact normal force for the penetration. For more information, click here.

    Damping Coefficient: Specifies a damping coefficient for the contact normal force.

    Damping Spline: The spline shows the contact normal force for the velocity of penetration. For more information, click here.

    Dynamic Friction Coefficient: Specifies a dynamic friction coefficient for the contact friction force. It has three options.

Dynamic Friction Coefficient: The constant friction coefficient is applied.

Friction Force Spline: The spline shows the fiction force for the relative velocity. It is recommended to use the spline that x and y values are defined as positive.

Friction Coefficient Spline: The spline shows the friction coefficient for the relative velocity.

    More: Specifies some friction coefficients for the contact friction force. Refer to Friction.

    Stiffness and Damping Exponent: Generates a non-linear contact normal force.

    Indentation Exponent: Yields an indentation damping effect. When the penetration is very small, the contact force may be negative due to a negative damping force, which is not realistic. This situation can be overcome by using the indentation exponent greater than one.

 

     Contact Output File: When this function is checked, RecurDyn creates the contact output file for contact information between sprocket and track links as follows. (Please refer to this option only output the results for track links, they checked at output tap in assembly information). The name of output file will be 'ModelName_ContactName.out'.

 

Col.

Variables

Descriptions

1

Time (sec)

Simulation Time

2

amount of contact point

Total number of calculated contact points

3

Pos_TX of Sprocket CM

Position X of Sprocket’s center marker

4

Pos_TY of Sprocket CM

Position Y of Sprocket’s center marker

5

Pos_TZ of Sprocket CM

Position Z of Sprocket’s center marker

6

Pos_PSI of Sprocket CM

Orientation Psi of Sprocket’s center marker

7

Pos_THETA of Sprocket CM

Orientation Theta of Sprocket’s center marker

8

Pos_PHI of Sprocket CM

Orientation Phi of Sprocket’s center marker

9

 

The index for contact points

10

Track Link ID

Contacted track link’s ID

11

Pos_TX of Track Link CM

Position X of Track Link’s center marker

12

Pos_TY of Track Link CM

Position Y of Track Link’s center marker

13

Pos_TZ of Track Link CM

Position Z of Track Link’s center marker

14

Pos_PSI of Track Link CM

Orientation Psi of Track Link’s center marker

15

Pos_THETA of Track Link CM

Orientation Theta of Track Link’s center marker

16

Pos_PHI of Track Link CM

Orientation Phi of Track Link’s center marker

17

 

The index for contact points

18

Global contact position

Global contact position

19

Contact position based on Sprocket

Contact position based on Sprocket

20

Contact position base on Track Link

Contact position base on Track Link

21

Normal force based on Sprocket

Normal force based on Sprocket

22

Friction force based on Sprocket

Friction force based on Sprocket

23

Normal force based on Track Link

Normal force based on Track Link

24

Friction force based on Track Link

Friction force based on Track Link

25

Velocity on Contact Reference Frame

Normal, Friction velocity based on contact reference frame

26

Velocity on Contact Reference Frame (Link Contact Point)

Velocity of Link Contact Point based on contact reference frame

()

27

Angular Velocity on Contact Reference Frame (Link Contact Point)

Angular Velocity of Link Contact Point on Contact Reference Frame

()

28

Velocity on Contact Reference Frame (Sprocket CM)

Velocity of Link Contact Point based on contact reference frame

()

29

Angular Velocity on Contact Reference Frame (Sprocket CM)

Angular Velocity of Link Contact Point on Contact Reference Frame

()

30

Velocity on Contact Reference Frame (Link Pin)

Velocity of Link Pin on Contact Reference Frame (

31

Angular Velocity on Contact Reference Frame (Link Pin)

Angular Velocity of Link Pin on Contact Reference Frame

(

32

Velocity on Contact Reference Frame (Sprocket Contact Point)

Velocity of Sprocket Contact Point on Contact Reference Frame

(

33

Angular Velocity on Contact Reference Frame (Sprocket Contact Point)

Angular Velocity of Sprocket Contact Point on Contact Reference Frame

(

34

Velocity on Contact Reference Frame (Relative (Link Contact Point –Sprocket Contact Point))

Relative Velocity (Link Contact Point – Sprocket Contact Point) on Contact Reference Frame

(

35

Velocity on Contact Reference Frame (Relative (Link Pin –Sprocket Contact Point))

Relative Velocity (Link Pin CM – Sprocket Contact Point) on Contact Reference Frame ()

 

Figure 2  definition of velocity