Water resistance as a spring constant

[Dell]

i am working on a project for a dynamic sculpture
we want the sculpture to be able to sway and our idea includes placing the sculpture on a floating base(almost like a catamaran) , with wind forces the sculpture will sway.

i would like to know how i may model the water resistance/buoyancy on the floating base using finite element software, the software i use has spring capabilities and i need to know how to evaluate the spring stiffness so it will react like water, to calculate the deformations

 

[mfb]

Water can flow (change the equilibrium positions), springs cannot. Springs can store potential energy in their length, water cannot (it is incompressible to a really good approximation). I doubt you can model water with springs.

 

[CWatters]

Springs typically produce a force that is proportional to their linear displacement. The force required to push a boat hull into the water depends on the volume of water displaced rather than the linear displacement.

So it depends on the cross section of your hull. If your hulls had a uniform cross section (say cubes of polystyrene?) then the volume displaced would proportional to the vertical displacement and it might be easy to model each hull as a vertical spring.

However water also has a considerable damping effect which might be significant if the things moving.

 

[henneh]

Just model the resistance as a pressure, it will have a favourable effect against the applied wind forces. Water should not be treated as a support, it has no shear strength unlike soils say which are typically modeled as springs

 

[rezeew]

Water resistance and buoyancy are important factors to consider when designing a dynamic sculpture on a floating base. In order to accurately model these effects, it is necessary to understand the concept of a spring constant in relation to water resistance.

A spring constant is a measure of the stiffness of a spring, and it is directly related to the amount of force required to deform the spring. In the case of a floating base, the water resistance acts as a spring, pushing against the base as it moves through the water. This resistance is dependent on various factors such as the shape and size of the base, the speed and direction of movement, and the density of the water.

To accurately model the water resistance and buoyancy using finite element software, it is important to first determine the spring constant for the base. This can be done by conducting experiments or using mathematical equations that take into account the aforementioned factors. Once the spring constant is determined, it can be input into the software as a material property, allowing for accurate simulations of the base's movement in water.

Furthermore, it is important to also consider the effects of buoyancy on the floating base. Buoyancy is the upward force exerted by water on an object, and it is directly related to the object's volume and the density of the water. This can also be incorporated into the finite element model by adjusting the base's weight and volume properties.

In summary, accurately modeling water resistance and buoyancy on a floating base for a dynamic sculpture requires an understanding of the concept of a spring constant and the factors that affect it. By properly determining and inputting the spring constant and adjusting for buoyancy, the finite element software can accurately simulate the movement and deformations of the sculpture on the floating base.