6 Replies Latest reply on Feb 20, 2018 7:51 AM by Shaodun Lin

    simulation for a structure

    Suhail P.

      hi,

      i have created the following structure, some circuitboards and some masses are panning to place at different location of the structure, so inorder to make the structure stable which simulations should i conduct?

      1.JPG

        • Re: simulation for a structure
          Siavash Khajehhasani

          Well your question is not that clear, but the following are my assumptions and a bit of guide:

          You may want to perform a static structural analysis to find out if this structure withstands against those loads and its weight as well. You can include those loads and masses with 'remote load/mass' tool.

          As aside note, it you get a chance of getting a proper training, that would be beneficial.

          • Re: simulation for a structure
            Shaodun Lin

            Hi Suhail:

             

            I think you can do a Frequency Response study for the structure.

            In this study, you can use the frequency sweep, for example from 25Hz to 1000Hz, to see where are the peaks and if those peaks affect your circuit board.

             

            Regards

              • Re: simulation for a structure
                Suhail P.

                thank you for your response,

                i have two more doubts

                1. for analysis of the structure i think i need to conduct static analysis,dynamic analysis and vibration analysis(natural frequency). for static and dynamic analysis i think the remote mass and force are enough instead of placing the actual circuit boards (since the actual circuit boards cause some errors while meshing). but for frequency analysis i think i have to place the boards itself since here the vibration transfer to the boards. for this what i am planning is to replace the circuit boards with dummy masses,that will make the same effects.

                so my doubts are,

                a)only these testes (static,dynamic frequency) are enough to ensure the stability of the structure?

                b)how to make dummy mass of a circuit board (what parameters have to be same(material,shape of board, center of gravity,location of support points relative to the cg)

                c)after doing these testes what parameters i have to ensure (factor of safety,stress ,displacement etc)

                 

                2. in addition to the structure i have to analyse the stability of a circuit board alone.

                i have created an assembly of a  circuit board having some connectors .now i need to know the stability of a small board connected to the main board through two connectors(almost like a RAM mounted on a motherboard in computer, but in my case both of the boards are parallel).for that what should i do, which simulation study should i perform ,like passing some vibration of known frequency to the board and to determine the value at which the board topple from the connector like that?

                only that frequency response is enough (and how to do this frequency response)

                  • Re: simulation for a structure
                    Shaodun Lin

                    Suhail P. wrote:

                     

                    thank you for your response,

                    i have two more doubts

                    1. for analysis of the structure i think i need to conduct static analysis,dynamic analysis and vibration analysis(natural frequency). for static and dynamic analysis i think the remote mass and force are enough instead of placing the actual circuit boards (since the actual circuit boards cause some errors while meshing). but for frequency analysis i think i have to place the boards itself since here the vibration transfer to the boards. for this what i am planning is to replace the circuit boards with dummy masses,that will make the same effects.

                    so my doubts are,

                    a)only these testes (static,dynamic frequency) are enough to ensure the stability of the structure?

                    b)how to make dummy mass of a circuit board (what parameters have to be same(material,shape of board, center of gravity,location of support points relative to the cg)

                    c)after doing these testes what parameters i have to ensure (factor of safety,stress ,displacement etc)

                     

                    2. in addition to the structure i have to analyse the stability of a circuit board alone.

                    i have created an assembly of a circuit board having some connectors .now i need to know the stability of a small board connected to the main board through two connectors(almost like a RAM mounted on a motherboard in computer, but in my case both of the boards are parallel).for that what should i do, which simulation study should i perform ,like passing some vibration of known frequency to the board and to determine the value at which the board topple from the connector like that?

                    only that frequency response is enough (and how to do this frequency response)

                    Hi Suhail:

                     

                    1. I think you need to perform the Static study to see if the stress/strain value on the PCB is too high. and then you need to do the Modal Time History Analysis and Random Vibration Analysis to understand the behavior of the circuit board under dynamic load condition.
                    2. In order to understand the stress and strain on PCB, I suggest you use the actual PCB model instead of dummy mass.
                    3. After doing above tests, you need to ensure the stress/ strain/displacement of the circuit board is within a reasonal limit.
                    4. For the RAM mounted on motherboard case, I suggest you perform Random Vibration Analysis to see the dynamic behavior. The input condition can be from ANSI / MIL test standard or from the Data Aquisition tools using multiple 3 axis accelerometers.