A Very Basic Problem

[MalteBrigge]

Hi eveyone ! I'am new to OpenSees and have tried to model one of my homework question from structural analysis course, a simple frame with a constant horizontal load acting at node3. I just want to perform static analysis, nothing related with EQ. But the problem is when i executed the code, i got a value of 3 and all my output files are actually blank.

Here are the basic sketch of the problem and my code;
http://imgur.com/e56bv5W

Thanks for your interest and have a nice day !

#### ce383 homework4 q1b ####
#### 27.06.2014, 21:00 ####
#### that one will be 2D model of given structure under lateral loading, sidesway permitted ####
#### Units in mm,newtons,MPa ####

### REMOVING PREVIOUS MODEL ###
wipe;


### MODELING ###

model BasicBuilder -ndm 2 -ndf 3;

### GEOMETRIC DEFINITONS ###

set spanw 500; ### span width ###
set outerch 600; ### outer column height ###
set innerch 400; ### inner column height ###
set E 200000; ### elastic modulus ###
set Ic 24010; ### Column, IPN380, inertia in strong axis bending ###
set Ac 10700; ### Column, IPN380, cross-sectional area ###
set Ib 24010; ### Beam, IPN380, inertia in strong axis bending ###
set Ab 10700; ### Beam, IPN380, cross-sectional area ###



### NODE DESCRIPTIONS ###

node 1 0.0 0.0;
node 2 [expr 2*$spanw] 0.0;
node 3 0.0 [expr $outerch];
node 4 [expr 2*$spanw] [expr $outerch];
node 5 [expr $spanw] [expr $innerch];
node 6 [expr $spanw] [expr $outerch];

### BOUNDRY CONDITIONS ###

fix 1 1 1 1;
fix 5 1 1 0;
fix 2 1 1 1;

### GEOMETRIC TRANSF. ###


geomTransf Linear 1;

### DISCRIPTION OF ELEMENTS; creating elastic beam-column elements, having same profile, IPN380 ###

element elasticBeamColumn 1 1 3 $Ac $E $Ic 1;
element elasticBeamColumn 2 2 4 $Ac $E $Ic 1;
element elasticBeamColumn 3 5 6 $Ac $E $Ic 1;
element elasticBeamColumn 4 3 6 $Ab $E $Ib 1;
element elasticBeamColumn 5 6 4 $Ab $E $Ib 1;



### CREATING A PLAIN LOAD PATTERN: horizontal force acting on node 3 with a magnitude of 100kN in +x direction ###

timeSeries Constant 1;


pattern Plain 1 1 {

load 3 100000.0 0.0 0.0

}

### END OF MODELING ###

### ANALYSIS ###

system BandSPD;
numberer RCM;
constraints Plain;
integrator LoadControl 1.0;
algorithm Linear;
analysis Static;
analyze 1;



### OUTPUTS ###

recorder Node -file Node3Disp.txt -time -node 3 -dof 1 2 3 disp;
recorder Element -file Column1.txt -time -ele 1 forces;
recorder Element -file Column3.txt -time -ele 3 forces;
recorder Element -file Column2.txt -time -ele 2 forces;

[nskok]

The recorder commands should be placed before the analyze command. I would move the recorder lines between your "### END OF MODELING ###" and "### ANALYSIS ###" sections. That should be all that you need to do to fix it.

- Nick

[MalteBrigge]

Thanks for reply Nick,
It worked perfectly.

Good Night !