# Simscape Multibody Flexible Library: Overview

This Simscape Multibody Flexible Body offers two methods for modeling flexible bodies: lumped parameter method and finite element import method. Your use case will determine which method is appropriate for you.

**Lumped Parameter Method**

View documentation for lumped parameter model

This method models the flexible body as a chain of mass-spring- dampers. You specify the cross section of the body, material, and number of elements, and MATLAB calculates the necessary parameters and constructs the chain of flexible elements.

This method is recommended if:

- The cross-section of the body does not vary along its length
- Expected deflection is in the linear range

**Finite Element Method**

View documentation for finite element model

This method superimposes superimposes deflection of the body onto rigid body motion. Degrees of freedom are added to the rigid body to model the deflection of the body. Those deflections are used to calculate the forces that resist deflection. That calculation is performed using the mass and stiffness matrices of the flexible body, which are often calcuated using finite element software.

This method is recommended if:

- The geometry of the flexible body is complex
- You have a means of calculating the mass and stiffness matrices for your flexible body (usually requires finite element software)
- The connection points to the rest of the system are known and not likely to change.