Use Hardpoints
When you select the install method Installed Length, you directly specify what the length of the spring is for the given design positions of the I and J coordinate references.
When you select the install method Use Hardpoints:
■The length of the spring is the distance between the spring's I and J coordinate references (DM(I,J)).
■The spring deflection at the input position is the spring's free length minus the distance between the I and J coordinate references.
For a linear spring:
Your template-based product, using the Adams Solver SPRINGDAMPER statement, calculates the spring force as follows:
Spring Force = - K*(DM(I,J) - Free_Length)
Note: | When you look at the ac_spring UDE definition in the Database Navigator, you will notice an OffsetCalc variable. In the equation above, OffsetCalc = Free_Length. |
For a nonlinear spring:
For nonlinear springs, the force in your template-based product is expressed using the Akima spline interpolation of a force versus spring deflection or spring length. Because the distance between the I and J coordinate references equals the installed length, OffsetCalc equals the free length:
Your template-based product, using the Adams Solver SFORCE statement, calculates the nonlinear spring force as follows:
■When using a force versus deflection characteristic:
OffsetCalc = Free_Length
■When using a force versus length characteristic:
OffsetCalc = 0
Spring Force = AKISPL(OffsetCalc + DM(I, J), 0, Spline)