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[24M1667]

! Define parameters

*SET, M1, 1.0       ! Mass 1

*SET, M2, 1.0       ! Mass 2

*SET, M3, 1.0       ! Mass 3

*SET, M4, 1.0       ! Mass 4

*SET, K1, 10.0      ! Spring constant 1

*SET, K2, 10.0      ! Spring constant 2

*SET, K3, 10.0      ! Spring constant 3

*SET, K4, 10.0      ! Spring constant 4

*SET, C, 0.5        ! Damping coefficient

 

! Define the model

/FILNAME, FourMassSystem, 1

/PREP7

 

! Create nodes

N, 1, 0, 0

N, 2, 1, 0

N, 3, 2, 0

N, 4, 3, 0

 

! Create elements (Spring elements)

ET, 1, LINK180

R, 1, K1

R, 2, K2

R, 3, K3

R, 4, K4

KEYOPT, 1, 1, 1

KEYOPT, 2, 1, 1

KEYOPT, 3, 1, 1

KEYOPT, 4, 1, 1

 

! Define element connectivity

E, 1, 2

E, 2, 3

E, 3, 4

 

! Define mass and damping

MP, EX, 1, K1

MP, EX, 2, K2

MP, EX, 3, K3

MP, EX, 4, K4

MP, D, 1, C

 

! Define boundary conditions

D, 1, ALL, 0

D, 4, ALL, 0

 

! Apply loads (forces)

F, 2, FX, F0 * SIN(omega * t)

F, 3, FX, F0 * COS(omega * t)

 

! Solution

/SOLU

ANTYPE, 4

SOLVE

 

! Post-processing

/POST1

PLDISP, 2

 

[mrife]

@24M1667

There is no question posted here....but if I had to guess an answer it is that Link180 does not use real constants to define the stiffess.  It uses sections.

Mike