Re: How to assembly a stiffness matrix ?

*To*: mathgroup at smc.vnet.net*Subject*: [mg60086] Re: How to assembly a stiffness matrix ?*From*: Francesco <emailnonvalida at email.it>*Date*: Thu, 1 Sep 2005 06:43:18 -0400 (EDT)*References*: <df3ito$mmo$1@smc.vnet.net> <df65u3$8hh$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Thanks a lot, i'm reading just now documentation and it seems a very rich package ! Regards, Francesco Oliver Ruebenkoenig ha scritto: > Ciao Francesco, > > we have a lot of open source tools to do that in mathematica. > You can download the software from: > http://www.imtek.de/simulation/mathematica/IMSweb/index.html > > If you have questions you might want to join the mailing list under: > http://elmo.imtek.uni-freiburg.de/mailman/listinfo/ims > > To you question: > I have a data structure imsMakeElementMatrix and imsAssemble. You fill all > the element matrices with imsMakeElementMatrix and put them into the > imsAssemble command and done you are. The online documentation can be seen > here: > http://www.imtek.de/simulation/mathematica/IMSweb/imsTOC/Numerics%20and%20Algor$ > > If you are into finite elements you might enjoy some of our application > examples at: > http://www.imtek.de/simulation/mathematica/IMSweb/imsTOC/Application%20Examples$ > > For transient problems I can recommend model order reduction. Assume you > have a high dimensional system of equations (say 30000 DOFs) you may be > able to find an approximate system of ( say 20 DOFs !!! ) that has very > much the same behaviour and then time integrate that ( which is of course > _very_ fast ) in the last step you do a re-projection to the original > system. For online documentation have a look at: > http://www.imtek.de/simulation/mathematica/IMSweb/imsTOC/Application%20Examples$ > > Please note: The online documentation is slightly dated - some 4 weeks or > so and not all documentation has all the nice pictures inside... > > We also have some tools to input for example ANSYS generated stuff (mesh, > element files and so on ) into mathematica. > > Nice export to povray and VTK script are possible. > > Does this help? > > Oliver > > > On Wed, 31 Aug 2005, Francesco wrote: > > >>I have a structure ( i.e. a crane ). I split the structure in a certain >>number of simple elements ( shaft or beam ). >>For each element i can build a local stiffness matrix of 12x12 element. >>Then i need to assembly this little matrixes in the big structure >>matrix. Dimension of the structure matrix is equale to: ( number of >>nodes x 6 ). nodes are cross point between elements. >> >>Each element matrix has a specifical location in the big matrix. >> >>How i can assembly the big structure matrix, starting by the single >>element matrix ? >>What i want to input is only the dimension of the structure matrix and >>the data of each single element matrix. The big structure matrix should >>be calculated by Mathematica. >> >>Thanks in adavance for help and sorry for my very bad english >> >>Regards, >> >>Francesco >> >> > > > > Oliver Ruebenkoenig, <ruebenko at imtek.de> > Phone: ++49 +761 203 7385 >