For the rods, if it is easier to draw solids than lines, you can do that and use the Prepare tab to convert the solids to Beam elements.

You can draw the triangle defined by the three ground points. Create an extra Component call it Ground that has three nodes to connect with a node on one end of rods 1, 9 and 12.

Separate components assures that when two rods meet at a common point, they each get a node on the end and don't share a node as that would weld the rods together into a single structure. Draw one rod in each Component as a line body. Open SpaceClaim and create 12 new Components. By using large values for the translational spring constants, such as 10^8 N/m and small values for the rotational constants, you will effectively have created a spherical joint that has a restoring moment to return the rods to their initial angles. Three translational spring constants and three rotational spring constants. This element defines 6 spring constants between two nodes. Open ANSYS Help and paste the following into the Browser window. This can be achieved by using a COMBI250 element. I see you have 12 rods that you want to connect with a spherical joint and a spring that creates a restoring moment proportional to the angle change. Maybe I just need some other type of joint for this purpose? (like in a revolute joint, where we have M = c*phi, but here in spherical joint we have 2 angles, as I don't want to account intrinsic rotation of cylinder around its axis). All I want is just to make some kind of connection between rods that would produce a counteracting moment that is proportional to change of angles in this joint. The problem here is that here the center of the joint is located in the center of the face and the radius of the joint is 0, so, as I understand, the moment would be 0. I didn't understand is it valid to define the joint between the ground and the top face of the cylinder as is shown on the 2nd picture (and also if I want to create a joint between 2 consecutive rods, I would need to define a joint between the bottom of one cylinder and the top of another). I read about this type of joint and how the friction moment is calculated based on radius, friction coefficient and surfaces of the joint. There is also a problem here with the spherical joints. Could you please explain it more? Is the structure on the picture appropriate for Static Structural? I actually haven't quite understand your note about 6 springs. All the other joints between rods should be also spherical with non-zero stiffnesses (that's what I meant when I wrote about springs). Briefly, there're 3 rods (on the right side of the picture) that have a spherical joint with the ground. Thanks peteroznewman for your answer! Here I apply the photo of the system I want to model. It would be very nice to get an answer for my question. Solution didn't converge, it has many errors, including 'Not enough constraints appear to be applied to prevent rigid body motion.' That's why I don't know is it possible to to solve static equilibrium problem of rigid body in Structural as it's always trying to prevent rigid body motion. In Static Structural I've also defined Remote Force because the solver said that usual Force can't be applied to rigid body. Anyway, I don't really know if it is possible to solve static problem in Rigid Dynamics where it's not possible to make a constraint of zero acceleration for example. I tried several times to apply the force from different locations. But I don't know is it ok to define the origin of remote force to be not on the face I want to apply this force to. I tried to apply load to the other lateral face of the cylinder.įirst I've tried Rigid Dynamics analysis but I faced the problem that only Remote Force can be applied to the rod. I tried to do that with 1 horizontal rod (modeled just by solid cylinder) connected to the ground in one of its lateral faces by revolute joint with non-zero rotational stiffness. Masses, materials and radii of rods don't matter because the problem is static. The problem is to find a static equilibrium of this system under the load. The load is constant and shouldn't change direction. There is also a load applied to the end of one of the rods.

Is it possible to find static equlibrium of system of rigid bodies using these types of analysis? In more detail, I want to model a system of rigid rods connected by springs.

I have a question about Rigid Dynamics and Static Structural.

Statics equilibrium 3d problem