1 Reply Latest reply on Dec 27, 2011 9:54 AM by sandeep pawar

    Pin/Bolt Check - Von Mises

    Dan Frey

      Hello,

       

      I have a simulation that includes fasteners. Solidworks computes the Factor of Safety for bolts using a combined load ratio. I've found the definition for this calculation in the Solidworks help files. I also see that for each fastener an axial, shear and bending force is calculated.

       

      I've been asked to determine the Von Mises stress for each bolt. Is there a way to get Von Mises stress for each bolt instead or at least principal stresses for each bolt rather than the combined load ratio. Or how does the Combined Load Ratio compare to Von Mises stress?

       

      Thanks,

        Dan

        • Re: Pin/Bolt Check - Von Mises
          sandeep pawar

          Dan,

           

          The reason, imo, simulation does not give you the stress is because different codes specify different ways of calculating bolt stresses. The more important thing to find out is the axial and shear loads. The bolt calculations within solidworks arent tied to any particular code, so you are suppossed to calculate the stresses. We follow VDI 2230.

           

          1. From the axial load and find out the max tensile stress based on teh root dia of the bolt. Let's call it T

          2. Then find the max torsional stress, again based on the root dia. You will have to use approriate coeffcients based on the grade you are using and thread friction. Lets call it S

          3. Von Mises stress = sqrt ( (T^2)+3*((k*S)^2)), k is usually 0.50

           

          Please look up VDI 2230 for procedure.

           

          Hope thsi helps.

           

          Sandeep