Design Example 5 Welded joint - Steel-stainless.org

Job No. Sheet 6 of 8 Rev B102, Route de LimoursF-78471 St Rémy Lès Chevreuse CedexFranceTel : +33 (0)1 30 85 25 00Fax : +33 (0)1 30 52 75 38CALCULATION SHEETJob TitleSubjectClientECSCECSC Stainless Steel Valorisation ProjectDesign Example 5 Welded jointMade by IR Date Aug 2002Checked by FH/NB Date Oct 2002Revised by MEB Date April 2006Appendix – Calculation of the force components at the critical point of the weldGeometric properties of the welded jointThere are two similar joints, one on each side of the column, resisting the applied loads.Only one of the joints needs to be examined. It is placed in the y-z plane.Throat area and positions of the centre of gravity and the critical pointThroat area (resisting section) of each of the joints made up of straight segments of lengthL i and constant throat size a is, for each 1mm of throat size:∫∑∑A a ds Awa= w, i aLw,i= = =∑Li= (2×175 + 250) =a a a600 mm 2 /mDistance of the centre of gravity from the vertical side (parallel to the z axis) of the jointof constant throat size a:∑yi( Aw,i / a)∑yiLi2×(87,5×175) + (0×250)y = = =≈ 51mmA / a L600∑w, i∑i51y ca = +175 - 51 = +124e ycLoad point125r c,aae zcz ca = -125Cy-y125d175z-zThe co-ordinates of the position of the critical point of the joint, the point (a), relative tothe principal axes through centre of gravity (C) are :y ca = + ( 175 − 51) = + 124 mm z ca = −125 mmNote: the point (d) might also be chosen as a potential critical point, for which :y cd = + ( 175 − 51) = + 124 mm z cd = +125 mmHowever, for the load case considered it is evident that the point (a) is the most critical.Inertias of the joint resisting sectionFor each of the joints, for each 1mm of throat size :I yc=a2∫ z ds23c = 2 × 175×125 + 250 /12 = 6,77×10 mm4 /mm6140