Installed Length
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.
For a linear spring:
Because the distance between the I and J coordinate references differs from the installed length, your template-based product calculates an offset distance to use in the force equation:
Free_Length - Installed_Length = OffsetCalc - dmCalc
OffsetCalc = Free_Length - Installed_Length + dmCalc
where dmCalc is the distance magnitude between the I and the J coordinates at the design configuration.
Your template-based product (using the Adams Solver
SPRINGDAMPER statement) calculates the spring force as follows:
Spring Force = - K*(DM(I,J) - OffsetCalc)
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 differs from the installed length, your template-based product calculates an offset distance to use in the force equation:
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 - Installed_Length + dmCalc
Spring Force =
AKISPL(OffsetCalc -
DM(I, J), 0, Spline)
■When using a force versus length characteristic:
OffsetCalc = Installed_Length - dmCalc
Spring Force = AKISPL(OffsetCalc + DM(I, J), 0, Spline)