Wheel Spring Ratio

Change in spring length per unit vertical displacement of the wheel center relative to the sprung mass.

Computed by:

SVCRAT

Input Variables Used:

Front and rear compliance matrices
Spring Body attachment markers
Spring Suspension attachment markers

Method:

SVC calculates a temporary compliance matrix to relate the wheel and spring motion. For full-vehicle models, the body degree of freedom is then removed from the compliance matrix.
Determine the normalized suspension to body vector
LSL = SQRT( LSPRNG(1)**2 + LSPRNG(2)**2 + LSPRNG(3)**2 )
Where:
   LSPRNG(1) - Global  X displacement of spring attachment on body wrt spring attachment on suspension
   LSPRNG(2) - Global  Y displacement of spring attachment on body wrt spring attachment on suspension
   LSPRNG(3) - Global  Z  displacement of spring attachment on body wrt spring attachment on suspension
   LSPRNG(1) = LSPRNG(1) / LSL
   LSPRNG(2) = LSPRNG(2) / LSL
   LSPRNG(3) = LSPRNG(3) / LSL
Compute change in spring length due to vertical force at wheel center (dot product of spring-end compliance and spring vector).
      DS =   CTEMP(7,3) * LSPRNG(1) +  CTEMP(8,3) * LSPRNG(2) +  CTEMP(9,3) * LSPRNG(3)
      Spring Ratio = CTEMP(3,3) / DS
      Spring Ratio = 1/Spring Ratio