Minimal Surface shape with gravity

In summary, the conversation discusses the concept of minimal surfaces, specifically in relation to the shape of a hammock and the equation of motion derived from the Lagrangian. The speaker mentions finding a solution in the form of a cone and discusses the limitations of other proposed solutions. The conversation also touches on the use of engineering analysis methods for sheets of material with physical properties and provides a source for further reading on plate theory.
  • #1
DuckAmuck
238
40
Minimal surfaces are sort of the "shortest path" but in terms of surface shapes.
So I figured I could characterize the shape of a hammock by adding the influence of gravity, much like you can get the shape of a catenary cable (y=cosh(x)).

The equation of motion I get from the Lagrangian is:
[tex] z_x^2 + z_y^2 + 1 = z ( z_{xx} (z_y^2 + 1) + z_{yy} (z_x^2 +1) - 2 z_x z_y z_{xy} )[/tex]
where z is the height of a point on the surface mapped to (x,y).

Of course, this is likely to have non-unique solutions just like other minimal surfaces.
One of the solutions I found is a cone:
[tex] z = \sqrt{x^2 + y^2} [/tex]
What does *not* work as a solution is a "2-d catenary", which is what I initially suspected as solution
[tex] z = cosh(x)cosh(y) [/tex]
Anyone else attempt this kind of problem? What were your findings? I'm basically just plugging things into the equation of motion and seeing if they work.
 
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  • #2
You can do these types of problem for sheets of material with real physical properties using standard engineering analysis methods .

No initially flat sheet with edge restraints can distort into any other shape without some stretching of the material .
 
  • #3
Would you mind linking me to a good source for this kind of engineering analysis methods?

Nidum said:
You can do these types of problem for sheets of material with real physical properties using standard engineering analysis methods .

No initially flat sheet with edge restraints can distort into any other shape without some stretching of the material .
 

Related to Minimal Surface shape with gravity

1. What is a minimal surface shape with gravity?

A minimal surface shape with gravity is a surface that is in a state of equilibrium under the influence of gravity. This means that the surface has the minimal possible area for its given boundary, and any small change in the surface would increase its area.

2. How is a minimal surface shape with gravity formed?

A minimal surface shape with gravity is formed when a surface is subjected to external forces, such as gravity, that cause it to take on a minimal area. This can occur naturally, such as in the formation of soap bubbles, or it can be designed and engineered by scientists and engineers.

3. What is the significance of studying minimal surface shapes with gravity?

Studying minimal surface shapes with gravity has many practical applications, including in the fields of architecture, material science, and engineering. Understanding how these shapes form and behave under the influence of gravity can help us design more efficient and stable structures.

4. Can minimal surface shapes with gravity exist in a vacuum?

Yes, minimal surface shapes with gravity can exist in a vacuum. In fact, some of the most well-known examples of minimal surface shapes, such as soap bubbles and soap films, exist in a vacuum with no other external influences.

5. How do scientists and mathematicians study minimal surface shapes with gravity?

Scientists and mathematicians use a variety of methods, including mathematical modeling, computer simulations, and physical experiments, to study and understand minimal surface shapes with gravity. These methods allow them to analyze and predict the behavior of these shapes under different conditions.

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