NDAESolve
- To: mathgroup at smc.vnet.net
- Subject: [mg40657] NDAESolve
- From: Paula Andreia Ennes <ennes at mec.ita.cta.br>
- Date: Sat, 12 Apr 2003 03:11:13 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi !
I need to solve DAEs, index 2, from within Mathematica 4.0.
My equations are nonlinear. These are generated in the dynamic analysis
of constrained mechanical
systems.
How is the NDAESolve notation ?
How to enter with the initial conditions ?
Do I need before to reduce my system for order 1 ?
How do I make that?
I have NDAESolve package (Analog Insydes demo).
These are my equations:
eq1 = (1/2)*(Transpose[qf[t]].d1ks.qf[t]) -
(1/2)*(Transpose[qf´[t]].d1ms.qf´[t]) + mm*s´´[t] ==
lambda2[t]*(ddndxds.qf[t]) + lambda1[t]*(dnds.qf[t])
eq2 = mm*g + mm*y´´[t] == -lambda1[t]
eq3 = InBloco*teta´´[t] == -lambda2[t]
eq4 = (ks.qf[t])+ (d1ms.qf´[t])*s´[t] + (ms.qf´´[t]) -
lambda2[t]*Transpose[dndx] - lambda1[t]*Transpose[nxs]
eq5 = s´´[t]*(dnds.qf[t]) + (nxs.qf´´[t]) - y´´[t] +
(2*s´[t]*(dnds.qf´[t])) + s´[t]^2*(d2nds.qf[t])
eq6 = s´´[t]*(ddndxds.qf[t]) + (dndx .qf´´[t]) - teta´´[t] +
(2*s´[t]*(ddndxds.qf´[t])) + s´[t]^2*(d2dndxds.qf´[t])
Where, the variables are:
s[t], y[t], teta[t] and qf[t] (vector).
But qt[f] = {{qf1[t]},{qf2[t]},{qf3[t]},{qf4[t]},{qf5[t]}}
Respectfully,
--
Paula Andreia Ennes
Instituto Tecnológico de Aeronáutica-ITA
Divisão de Engenharia Mecânica-Aeronáutica
Pós-Graduação - Área de Dinâmica de Sistemas e Mecatrônica
12228-900 São José dos Campos - SP
Tel: +55 12 3947 5907 / 9123 2527
E-mail: ennes at mec.ita.cta.br
paula_ennes at yahoo.com