Learning Forum

[Nouran Muhammad]

Hi, 

I am using Electric module in Ansys Workbench to simulate high density voltage spinal cord stimulation. The voltage signal parameters are: 5 V peak, 500 Hz frequency and 500 microseconds pulse width. I can't find a way to incorporate the pulse width information. I inserted a voltage object and choose function, but i only can write: 5000*cos(2*3.14*500*(10^6)*time). How to add the pulse width information to generate pulsed signal?

 

[wrbulat]

Is your objective to define a square or trapezoidal wave form rather than a sinusoid? If so, you could add a command object containing the following. Append to the end of it the command to assign the voltage to a face, i.e.,

d,V_face,volt,%V1%

where V_face is a component name assigned to the face to which the time varying trapezoidal voltage waveform is to be applied.

 

Also, put an empty command object under the Solution branch in the tree. A plot of the voltage waveform should appear under it after you solve.

 

 

C***************************************************

C*** PARAMETERS DEFINING VOLTAGE TRAPEZIODAL WAVE

C***************************************************

V_ampltd=100 ! AMPLITUDE OF APPLIED VOLTAGE

frqncy=0.1 ! FREQUENCY

P=1/frqncy ! CORRESPONDING PERIOD (DO NOT EDIT)

t_rise=P/20 ! RISE TIME

t_dwell=P/4 ! DWELL TIME

t_fall=P/15 ! FALL TIME

nprds=5 ! # OF PERIODS

t_final=nprds*P ! END OF TRANSIENT (DO NOT EDIT)

 

 

C***************************************************

C*** DEFINE TRAPEZIODAL WAVE

C***************************************************

*dim,V1,table,4*nprds+1,,,time ! DIMENSION ARRAY TO HOLD TRAPEZOIDAL WAVE DATA

*dim,keytimes,,4*nprds ! KEYTIME ARRAY FOR TSRES IF THIS IS A THERMAL TRANSIENT

 

*do,i,1,nprds ! PLACE DATA IN ARRAY

 V1(4*(i-1)+1,1)=0

 V1(4*(i-1)+2,1)=V_ampltd

 V1(4*(i-1)+3,1)=V_ampltd

 V1(4*(i-1)+4,1)=0

 V1(4*(i-1)+5,1)=0

*enddo

 

*do,i,1,nprds ! PLACE CORRESPONDING TIME VALUES IN ARRAY

 V1(4*(i-1)+1,0)=(i-1)*P

 V1(4*(i-1)+2,0)=(i-1)*P+t_rise

 V1(4*(i-1)+3,0)=(i-1)*P+t_rise+t_dwell

 V1(4*(i-1)+4,0)=(i-1)*P+t_rise+t_dwell+t_fall

 V1(4*(i-1)+5,0)=(i)*P

*enddo

 

*vfun,keytimes(1),copy,V1(2,0) ! COPY V1 TIME VALUES TO keytimes ARRAY

 

/axlab,x,Time (s) ! CREATE png IMAGE FILE OF TRAPEZOIDAL WAVE

/axlab,y,ELECTRODE VOLTAGE

/sho,png

*vplot,V1(1,0),V1(1,1)

/sho,close

 

 

/solu

 

tsres,%keytimes% ! USE KEYTIMES ARRAY (APPLICABLE IF THERMAL TRANSIENT ANALYSIS)

dt_min=min(t_rise,min(t_dwell,min(t_fall,P-t_rise-t_dwell-t_fall))) ! MINIMUM TIME BETWEEN POINTS IN V1 TABLE ARRAY

dt_max=max(t_rise,max(t_dwell,max(t_fall,P-t_rise-t_dwell-t_fall))) ! MAXIMUM TIME BETWEEN POINTS IN V1 TABLE ARRAY

autots,on

deltime,0.5*dt_min,0.5*dt_min,dt_max ! DELTIME (COMPATIBLE WITH TSRES KEYTIMES)

outres,all,all

 

/eof

[wrbulat]

Also, if your objective is to calculate transient thermal response to Joule heating, you might consider setting the model up in a transient coupled fields analysis system. 

[Nouran Muhammad]

No, i want to apply a pulsed signal like this