Can a single-DOF system with non-linear damping be solved analytically?

In summary, the conversation is about trying to solve a second order non-linear ODE for a single-DOF system with a non-linear damping component. The equation was attempted to be solved in Maple but without success. It was then mentioned that x'x' may be a mistake and the equation can be reduced to a first order non-linear ODE. However, in the general case, there is no known analytical method to solve it and it may be solved using numerical calculus or approximate developments.
  • #1
actionman26
2
0
Hi I am trying to solve an analytical solution for a single-DOF system with a non-linear damping component:

mx'' + B2x'x' + B1x' + Kx = 0.

Tried in maple with no success with the non-linear term in the eqn.

Thanks in advance.
 
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  • #2
actionman26 said:
mx'' + B2x'x' + B1x' + Kx = 0.
Writing x'x' looks odd, some mistake?
 
  • #3
The second order non-linear ODE :
mx'' + (B2)(x')² + (B1)x' + Kx = 0
can be reduced to a first order non-linear ODE :
Let dx/dt = p(x) which leads to :
m*(dp/dx)*p +(B2)*p² +(B1)*p +K*x = 0
Except for particular values of the coefficients, i.e. in the general case, there is no known analytical method to solve this non-linear ODE in odrer to obtain the result on the form of a combination of a finite number of standard functions.
You may solve it by numerical calculus or by approximate developments.
 

1. What is a Second Order Non-Linear Differential Equation?

A Second Order Non-Linear Differential Equation is a mathematical equation that involves a function and its derivatives up to the second order, where the function is not proportional to any of its derivatives and may also involve non-linear terms. In simpler terms, it is an equation that relates an unknown function to its derivatives, and the function is not directly proportional to these derivatives.

2. What are some examples of Second Order Non-Linear Differential Equations?

Some examples of Second Order Non-Linear Differential Equations include the Van der Pol oscillator equation, the Lotka-Volterra equations, and the Lorenz equations. These equations are commonly used in physics, engineering, and other fields to model complex systems and phenomena.

3. How do you solve a Second Order Non-Linear Differential Equation?

Solving a Second Order Non-Linear Differential Equation can be a challenging task and often requires advanced mathematical techniques. One approach is to use numerical methods, such as Euler's method or Runge-Kutta methods, to approximate solutions. Another approach is to use analytical methods, such as the method of undetermined coefficients or variation of parameters.

4. What are the applications of Second Order Non-Linear Differential Equations?

Second Order Non-Linear Differential Equations are widely used in various fields, including physics, engineering, economics, and biology. They are used to model complex systems and phenomena such as population dynamics, chemical reactions, and mechanical vibrations. These equations also have practical applications in control systems and signal processing.

5. What is the difference between a Second Order Non-Linear Differential Equation and a Second Order Linear Differential Equation?

The key difference between a Second Order Non-Linear Differential Equation and a Second Order Linear Differential Equation is that the latter involves only linear terms, meaning that the unknown function is directly proportional to its derivatives. This makes Second Order Linear Differential Equations easier to solve compared to their non-linear counterparts, and they have a wider range of analytical techniques available for their solution.

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