[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
## [Getfem-users] Stiffness matrix for linear elasticity

**From**: |
Roman Putanowicz |

**Subject**: |
[Getfem-users] Stiffness matrix for linear elasticity |

**Date**: |
Tue, 28 Dec 2010 03:07:08 +0100 |

**User-agent**: |
Mutt/1.5.13 (2006-08-11) |

Dear All,
I am looking at function asm_stiffness_matrix_for_linear_elasticity.
There is code like this:
generic_assembly assem("lambda=data$1(#2); mu=data$2(#2);"
"t=comp(vGrad(#1).vGrad(#1).Base(#2));"
"M(#1,#1)+=sym(t(:,i,j,:,i,j,k).mu(k)"
"+ t(:,j,i,:,i,j,k).mu(k)"
"+ t(:,i,i,:,j,j,k).lambda(k))");
I cannot figure why this is written as above.
In the Navier's equation we have terms
mu * u_i,jj + (mu+lambda)*u_j,ji
so I would expect
the second and third components at mu and lambda, respectively, be the same.
I would really appreciate a hint on this as I have serious doubts in my
ability to juggle the tensor indices :-).
Best regards
Roman
--
Roman Putanowicz, PhD < address@hidden >
Institute for Computational Civil Engng (L-5)
Dept. of Civil Engng, Cracow Univ. of Technology
www.l5.pk.edu.pl, tel. +48 12 628 2569, fax 2034

**[Getfem-users] Stiffness matrix for linear elasticity**,
*Roman Putanowicz* **<=**