Spring and dashpot in series

[zhankeliu]

I want to model a spring and dashpot in series between two nodes. It is easy to define them in parallel, but hard in series. Does anyone have idea about this? THANKS!

 

[brep]

Use 2 connector elements in series. Put spring behavior on one and damper on the other. (within a single connector section multiple behaviors will act in parallel)

Connectors are by far the most powerful and flexible modeling construct - check out the available behaviors...

 

[zhankeliu]

Thanks, Brep. It seems to me that one connector element should be between two nodes or ground and a node. Currently, I have only two nodes, and I want to put two connector elements in series, to model a spring and a dashpot in series between these two nodes. This seems difficult for me.

 

[bassmanjax]

Put a node between the two existing nodes and use two connectors, as brep says.

x----||-----x--/\/\/\---x

If you want the nodes to stay colinear, you could use *COUPLING and *KINEMATIC to tie the relevant degrees of freedom.

Regards

Martin

 

[zhankeliu]

Thanks, Martin. Should the added node between the two existing nodes have mass? If yes, then how much should the mass be? I actually tried this scheme. I got an error message if I add the node without mass. Then I assigned an extremely small point mass to the middle node and I got funny results. I am wondering if we can have a node without mass in ABAQUS.

 

[bassmanjax]

Depends what sort of analysis you're trying to do. If you are trying to solve a dynamic problem in Explicit, then you will definitely need a mass.

What type of analysis are you trying to do and what are you trying to model?

 

[zhankeliu]

Thanks, Martin. It is right on the point.

I am trying to model the transient behavior of mass-spring-damper system subject to transient loading. The simple mass-spring-damper system I am adopting now is the Maxwell model (which is two point masses connected by a spring and a dashpot in series).