# Finite Element Method

1. Aug 18, 2016

### S K

Does anyone know how to find the total mass matrix of two coupled element by using Finite Element Method?

2. Aug 18, 2016

### Mech_Engineer

You haven't been specific enough in your question. What kind of elements, and for what purpose?

3. Aug 18, 2016

### S K

Actually I am trying to find the total mass matrix of flexible two link which are coupled by revolute joint. The figure of two flexible links can be found in the following website.

The mass matrix of link 1 is given by
M1=[m11 m12 m13 m14 m15 ;
m21 m22 m23 m24 m25 ;
m31 m32 m33 m34 m35 ;
m41 m33 m34 m44 m45 ;
m51 m52 m53 m54 m55 ];

theta1, w1, alpha1, w2, alpha2 are the states where theta1 is joint angle of link 1 w is flexural displacement and alpha is flexural slope

Similarly, the mass matrix for link 2 is given by

M2=[M11 M12 M13 M14 M15 M16 M17 M18 ;
M21 M22 M23 M24 M25 M26 M27 M28 ;
M31 M32 M33 M34 M35 M36 M37 M38 ;
M41 M33 M34 M44 M45 M46 M47 M48 ;
M51 M52 M53 M54 M55 M56 M57 M58 ;
M61 M62 M63 M64 M65 M66 M67 M68 ;
M71 M72 M73 M74 M75 M76 M77 M78 ;
M81 M82 M83 M84 M85 M86 M87 M88 ]

Theta1, w2, alpha2, theta2, u2, phi2, u3, phi3 are the states for link 2.

So, anyone knows how to find the total mass matrix of the system?

4. Aug 22, 2016

### Mech_Engineer

5. Aug 22, 2016

### S K

Thank you very much