eval(demosdt('echoon'));
clear FEnode FEelt FEel0  % just to make it clean

% Illustration of FEMESH capabilities and standard finite element computations
% for a few plate/shell examples
%
% Use doc('sdt/fem') to access the introduction to FEMESH. The associate
% basic example is treated in the D_TRUSS demo.

% For a first case, one will build a square plate by defining two nodes, a beam
% connecting these nodes, extruding it to form a quadrilateral and dividing the
% element in a regular 4 by 4 mesh

femesh('reset');
FEnode=[1  0 0 0  0.0 0.0 0.0; 2  0 0 0  0.0 1.0 0.0];
femesh(';objectbeamline 1 2;extrude 1 1 0 0;divide 4 4;plotel0');
fecom('view3');

%demosdt('pause'); %----------------------------------------------------------

% To compute the modes of this model one defines material and section properties
%

% data structure format of FE model : see doc fem
model=struct('Node',FEnode,'Elt',FEel0, ...
   'pl',m_elastic('dbval 1 Aluminum'), ...
   'il',p_shell('dbval 1 kirchoff 5e-2'));

% defines boundary conditions here clamped on left edge (x==0)
model=fe_case(model,'fixdof','Clamped edge','x==0');


% computes and displays modes
 def=fe_eig(model,[6 20 1e3]);
 cf=feplot; cf.model=model; cf.def=def;
 fecom('colordata enerk');fecom('view3')

demosdt('pause'); %-------------------- -------------------------------------

% We will now consider a typical problem used to evaluate the quality of
% finite element model predictions.
% One considers a quarter plate with a distributed static load


model=fe_case(model','reset', ...
 'fixdof','Bending',[.01;.02;.06], ...
 'fixdof','simple support',feutil('findnode y==1 | x==1',model)+.03, ...
 'fixdof','symmetry_y',feutil('findnode y==0',model)+.05, ...
 'fixdof','symmetry_x',feutil('findnode x==0',model)+.04);

% now define a uniform volume load
data=struct('sel','groupall','dir',[0 0 9.81]);
model=fe_case(model,'FVol','Gravity',data);


fe_case(model,'info')
Load=fe_load(model);


% The response is then easily computed and displayed using
def=fe_simul('static',model);

cf.def=def;fecom(';sub 1 1 1 3 2');

demosdt('pause'); %----------------------------------------------------------

% For 3-D shells one can for example build a short tube using

FEnode=[1  0 0 0  0.0 0.0 0.0; 2  0 0 0  0.0 1.0 0.0];
femesh(';objectbeamline 1 2;rev 10 o 0 0 .1 360 0 1 0;divide 1 3');
fecom('showline');

model.Node=FEnode; model.Elt=FEel0;
model=fe_case(model,'reset');


def1=fe_eig(model,[5 20 -1e6]);
cf=feplot; cf.model=model; cf.def=def1;


%[md1,f1] = fe_eig(m,k,[5 20 1e3]);cf.def(1)={md1,mdof,f1/2/pi};
fecom(';ch7;scd.05');

%-----------------------------------------------------------------
eval(demosdt('echooff'))

%       Etienne Balmes, Jean Michel Leclere
%       Copyright (c) 1990-2005 by SDTools, All Rights Reserved.
%       $Revision: 1.8 $  $Date: 2005/11/04 17:19:27 $