3 Replies Latest reply on Jan 10, 2018 5:28 AM by Jon Dahlgren

    stress analysis on bolted bracket

    Alex Immanuel Thainese

      solidworks model link:    Z BRACKET SW MODEL-simulation error.zip - Google Drive

      BELOW IS THE IMAGE OF A BRACKET

      z BR MODEL.png

       

       

      THIS BRACKET IS TO BE USED TO SUPPORT A MARBLE STONE .

      To perform a stress analysis , I used fixed geometry at the slot region and applied the load on the pin which is con nected to the marble .

      z BR MODEL2.png

      The contact set  is used is bonded to make the bracket , pin and flat head bolt to act as one system

      z BR MODEL3.png

      I am unable to solve this and I ma getting following error.

      z BR MODEL4.png

       

      MY QUESTION:

       

      1. 1) HOW TO RECTIFY THIS ERROR  and run the simulation ??
      2. 2) What are the appropriate contact which should be used  ??
        • Re: stress analysis on bolted bracket
          Jitesh Fichadiya

          you should go ahead and simplify the screw, as it has threads it will create problem while mashing, go ahead and remove the threads and apply local bonded connector and then do the simulation again, if you want to find the stresses on the bracket then this much simplification wont affect much to your over all results...

          • Re: stress analysis on bolted bracket
            Alex Immanuel Thainese

            here again i provide details of the bracket model which i want to analyse with static study .

             

             

             

            MODEL DESCRIPTION:

             

            pic 1.png

            CONTACTS : rigid connector for flat head bolt  & Bracket

             

                                    virtual wall  for the zee bracket

             

             

             

             

            Load acting on head of pin is 549 N

            ISSUE NO. 1 :  MOMENT OF INERTIA CALCULATION

             

            Hand calculation  : Moment of inertia  Ixx  =  50 x 53 / 12   = 520.833 mm4.

                                              Moment of inertia  Ixx  =  50 x 53 / 12   =  52083.3 mm4.

            Value reported for Ixx &  IYY   is right

             

              pic 2.png

             

            HAND CALCULATION OF STRESS  at marked location :

             

                     pic 3.png

            pic 4.pngpic 5.png

             

             

             

             

            Fdw =  549 N

            Lmax 2 =  39.55 mm

            Moment  = (Fdw)  x (Lmax 2 ) =   549 x 39 .50 =  21685.5 N-mm

            Section modulus  =  ( B 2 -B 12 )  x (B1)3 / 6  = (50 -10) x 52 / 6 =  166.67 mm3

            Stress  =  moment / section modulus =  21685.5/166.67 = 130.11 N / mm2

             

            QUERY:

            1) The solidwork results are not matching.  When i see normal stress in x , normal y and normal z.

             

            2) SW displays msg for large displacement analysis , why ?

             

            3) stresess in inplane direction  are are very high, cant find the reason  ?

             

            model link :

            https://drive.google.com/open?id=1-BQUPXjFrDq58AnWJEN7Ab1iblI60PUB

              • Re: stress analysis on bolted bracket
                Jon Dahlgren

                I haven't checked the model but the large displacement flag indicates that something moves much, is this expected?

                Can you show a displacement plot?

                 

                Edit: I don't know why you add the load on the pin and I suspect that gives you strange behaviour. It seems better to apply it to the flat bolt directly.

                I'd also use bonded connection between the bolt and bracket since now you've locked the whole thread area of the bolt to the bracket.