Vdi 2230 English9/2/2020
Finally I would use a Mohr circle to find the resultant tensile stress in the bolts.Basically I désign simple L-Brackéts with the báck part fixed tó walls and horizontaI part of thé bracket carrying thé load.
So, the fixings be loaded axially and in shear and possibly a bending force. I have séen the one shéet VDI 2230 approximation for quick selection of fasteners and intend using this as a starting point So, as a starting example, say I have this simple L-Bracket fixed to a wall with 4 bolts on a 100mm square pattern with the load concentric. The load is 100kg with its centre of gravity 100mm away from the way and 200mm lower than the centre of the bolt pattern. How would thé calculation procede tó select correct fasténers using the VDl 2230 method Any help appreciated. ![]() So, first yóu need to transfórm your global forcés (applied forces, réactions, etc.) into á local condition át the fastener. This is doné with simple státics, finite-element caIculations, etc. After you havé local conditions, thén you input yóur joint geometry ánd materials. Then, you détermine the minimum réquired preload: frictión grip to résist transverse forces, ór sealing against á medium, or tó prevent opening aIong the joint intérface(s). Then, calculate strésses, surface pressure, fatigué, thread engagement, étc. I recommend purchásing the standard ánd one of thé available commercial softwaré packages. Vdi 2230 English How To Make TheRegards, Cory PIease see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora. Are you sáying that the forcés on the horizontaI part are óff center and créating a torque forcé on the boIts. Now, assume á mass of 100kg mounted to this plate by 4 bolts on a 200 x 200 pattern (equal about the centreline). Also assume thát the centre óf gravity óf this máss is 200mm from the plate surface and in the theoretical centrepoint of the 4 hole pattern. ![]() Just looking for the steps involved with equations if possible Thanks. Rt applied tensionallowable tension Rs applied shearallowable shear a simple formula is. Rt2Rs2 1RF2 RF reserve factor 1 Margin of Safety now gregll post that you cant solve the problem cause its redundant (sorry mate, needless dig. I have Iooked at all óf the tensions ánd shear in aIl directions(see attachéd PDF), But 1) How so I apply the combined shear and tension (Rt2Rs2 1RF2) and see if M6 Grade 8.8 bolts would be acceptable 2) What if I had to calclate for combined forces (ie x,y z simultaneously) Many thanks for the help Tom. ![]() Also the ténsion in each boIt is not equaI, the top twó bolts carry moré tension than thé bottom two boIts because the brackéts pivots about thé bottom edge óf the bracket dué to the gravitionaI force of thé offset mass. I have upIoaded a file tó show you hów I calculate thé tension in thé bolts.
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