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Abaqus applying a periodic load

Submitted by vamsi.char on
research

Hi everybody,

 I modeled the
suspension system of freight train which comprises of a sideframe, bolster, two
frition wedges, wedge springs and bolster springs. I completed my model
successfully when i applied a concentrated force of magnitude 500 (pointing
downwards on the bolster) at the center of the bolster. Now when i am trying to
apply a periodic amplitude in the load instead of ramp i cannot run my model
successfully. I dont know what i am doing wrong. Is there any other way to
apply a periodic loading or should i change the time period or time increment
in the step when i apply a periodic amplitude? 
Anybody who has any idea about perioic loading or how to apply a
periodic load please let me know where am i going wrong.!?

 

I have attached my input file since its too large to paste in here.

Somebody please look into this and atleast let me know what is wrong and the changes i need to make. I would really apreciate any kind of inputs.!

 

Thanks

Vamsi 

Attachment Size
blog.pdf 695.33 KB
jason Zhu

 Hi Char，



 I downloaed ur model and ran it. I found the dimensions in ur model us not right.



For example, the density set to be 7850 and the Young's modulus is 210. I think u can not find such a soft material.



The   Young's modulus should be  210,000,000,000.



 



I also tried the dynamic modeling and the model runs very well if we modify the modulus.



 



 



Jason Zhu Best Regards

Wed, 06/06/2012 - 07:55 Permalink
vamsi.char

Thank you so much jason.! Thanks man i really appreciate it .!

As you ran my model it is finite element model of freight train suspension system an di have a couple of questions if you dont mind

(1) do you recommend using static-general or dynamic step for my model

(2) to apply a load with different frequencies should i use tabular or periodic amplitude in the load and what load should i be using concentrated force, pressure load or ?

 

Thanks a ton again for your response

Regards

Vamsi 

Thu, 06/07/2012 - 02:16 Permalink
jason Zhu

 Hi CHar,

 Glad to disccuss wi th you.

1) Since  you want to apply dynami load, I recommend you using the explicit dynamic for the model

2) Tabular or periodic amplitude is desirable for this case.

3) concentrated force orpressure load.I think this depends on the aim of your analysis

 

 

Jason Zhu
Best Regards

Thu, 06/07/2012 - 08:50 Permalink
vamsi.char

Hi Jason,
 
I am sorry if i am bothering you but i have a couple more questions,
 
(1) When i'm using an impact load with sine or cosine amplitude is it possible for me to get the sine or cosine curve in my plot of displacement? If we can do that how do we get sine or cosine curve in the displacement plot.?
 
(2) how to plot relative and absolute displacement? All i can see in the field output is spatial displacement, how can we plot relative and absolute displacement.?
 
(3)All of my plots are short they dont go on, you know what i mean? how can i see graphs starting from a straight line showing all the variations for some time and then again going back to a straight line, should i vary the time period or anything in the step for me to get a graph like that .!?
 
Thanks a ton
\/amsi
Thu, 06/14/2012 - 21:41 Permalink
vamsi.char

Hi Jason,
 
I am sorry if i am bothering you but i have a couple more questions,
 
(1) When i'm using an impact load with sine or cosine amplitude is it possible for me to get the sine or cosine curve in my plot of displacement? If we can do that how do we get sine or cosine curve in the displacement plot.?
 
(2) how to plot relative and absolute displacement? All i can see in the field output is spatial displacement, how can we plot relative and absolute displacement.?
 
(3)All of my plots are short they dont go on, you know what i mean? how can i see graphs starting from a straight line showing all the variations for some time and then again going back to a straight line, should i vary the time period or anything in the step for me to get a graph like that .!?
 
Thanks a ton
\/amsi
Thu, 06/14/2012 - 21:39 Permalink