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How to setup output funcitons from second-order system equations?
Posted 25 janv. 2018, 13:01 UTC−5 MEMS & Nanotechnology, Heat Transfer & Phase Change, LiveLink for MATLAB, Parameters, Variables, & Functions Version 5.3a 2 Replies
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[Hi all, I have a problem about how to setup the output function about second-order system equations,such as in elctro-thermal- structure analysis. I know use "mphstate" ,it can output the C and D matrix through creating a domain point probe, then can setup output function in state-space system: y=Cx+Du, and use"mphmatrix", we can get the E(mass),K(stiffness),D(damping) matrix and L(load vector), but I do not know how to set up C and D which I needed in my Comsol models about electro-thermal-structure analysis ? I use "Joule heating and thermal expansion" to simulate my MEMS model, and I guess the system equations maybe second-order ODEs and do not decribed as state-sapce system, so in this case "mphstate" will not valid. So how to get C and D? Is it possible in the "Joule heating and thermal expansion" study? Thanks
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Hi ,does anybody help me about the questions? I wander how to get the input and output matrix from Comsol， thanks
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Hi, I am facing a similar problem. I am unable to extract state space matrices of a second order system. The command 'mphstate' is valied only for first order state space systems. Kindly help me with this.