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Complex equations in Motion

Question asked by Alan Thomason on Feb 6, 2015
Latest reply on Feb 13, 2015 by Jared Conway

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I often need to have forces applied to components that are based on more than one independent variable. What I do in these cases is to apply a force to a fixed object, knowing that it will have no effect. I then attach a results plot to that force. I can then use the results plot in an equation for another force.

What I would rather do is to have an equation space in which such complex equations and tables can be placed. Creating false forces and having transitional variables just to do this is confusing, inefficient, and could potentially slow the simulation.

Thanks in advance...

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Jared Conway Feb 6, 2015 6:14 PM
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so you are using the forces like variables?

and you don't need to know how to create the expressions:
2015 SOLIDWORKS Help - Expressions and Functions for Forces and Motors
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- Alan Thomason @ Jared Conway on Feb 6, 2015 9:54 PM
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  Hi Jared...
  
  Yes, I use the expressions and functions now. Sometimes you want a time based 'step' function. Then you need to have an action proportional to that function. So it is mixed. The expressions and functions are useful in one way, the segments are useful in another.
  
  By the way, the datapoints method has a bug and so is not useful at all. It's addresses are mapped to the wrong spaces so who knows what they are doing to the overall dataset.
  
  To cite a specific example, you might want to turn a motor on and off. Off until 2sec, then a sharp transition to 'ON'. Left 'ON' for 2sec then back 'OFF' again. The motor equation would need dependency on shaft speed to be accurate. So, for example, you might simulate a motor with a shaft torque of
  10 [N-m] * (1 - {Angular Rate 1}/10000)
  This simulates reasonable motor behavior but if you want to turn it off and on you need a different method than the equation editor. A segment table works very well, but you cannot enter the independent variable of shaft speed. The solution is to multiply the torque equation times the segment table. In order to use the segment table, I create the false torque, apply it to a fixed object, measure it as a result (which gives it a name) and then I can multiply it by the torque equation.
  
  (10 [N-m] (1 - {Angular Rate 1}/10000]) * {Force_1}
  where {Force_1} is the result monitoring the 'ON' 'OFF' table.
  
  What I would dream of is a function editor that would allow entry of any types of these equations to be calculated each time step. This way such complex methods would not be required, much much more could be accomplished, and the 'code' would be easier to read.
  
  Thanks,
  Alan Thomason
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  - Jared Conway @ Alan Thomason on Feb 13, 2015 12:31 PM
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    does adams have this?
    
    have you submit enhancement requests for this already or already got confirmation that what you're wanting/trying to do isn't possible?
    
    when i read your description above, it seems like there is some over complication going on regarding your motion simulation because it seems like the tools that exist in the software should be able to do what you want with a combination of keys and segments..etc. but maybe what i'm missing is the goal of the additional accuracy you're trying to include in your simulation?
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Complex equations in Motion

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