Final Project 2010 E. Tarallo, G. Mastinu POLITECNICO DI MILANO, Dipartimento di Meccanica
Es02 Project 2010 Summary 2 Guidelines to the project: The project may be performed by group of a maximum 3 students; A complete report must be produced about the project; The report must include: a complete description of geometries, properties, interactions and meshes; a study of convergence; critical considerations about assembly method (i.e., position and number of bolts); The complete work together with the exercise-book must be delivered at least one week before taking the exam.
Es02 Project The considered frame
Es02 Project The considered frame
Es02 Project The considered frame * All the drawings have been put in the website as pdf formats
Es02 Project Loads A B C D Type A(kN)B(kN)C(kN)D(kN) *All the directions in this figure are POSITIVE *The position of the forces A and B should be extracted from the drawings
Es02 Project Different Analysis Modeling: 1.Beam Elements (use constant section) 2.Shell Elements (use constant thickness) 3.Solid Elements (check welded or bolted joints) Analysis: A.Static general (use constant loads and right boundary) B.Frequency linear perturbation (find first 5 natural frequency) C.Dynamic, implicit (use sinusoidal input of amplitude equal to static load and variable frequency – look at phase problem)
Es02 Project Appendix A – welded joints Main guidelines to verify a welding: Standard: UNI EN 1993: Eurocodice 3: Progettazione delle strutture di acciaio Parte 1-8: Progettazione dei collegamenti Consider only fillet-weld According to the prismatic stress status: normal stress perpendicular to throat normal stress parallel to the axis of weld shear stress perpendicular to the axis of weld shear stress parallel to the axis of weld is not considered when verifying the design resistance of the weld Welds between parts with different material strength grades should be designed using the properties of the material with the lower strength grade.
Es02 Project The design resistance of the fillet weld will be sufficient if the following are both satisfied: where: is the nominal ultimate tensile strength of the weaker part joined; is the appropriate correlation factor taken from table; is For simplified criteria see the standard For other criteria see std CNR Appendix A – welded joints
Es02 Project Appendix B – bolted joints Main guidelines to verify a bolted joint: Standard: UNI EN 1993: Eurocodice 3: Progettazione delle strutture di acciaio Parte 1-8: Progettazione dei collegamenti Bolt classes: f yb (yeld stress) f ub (ultimate stress) Category of bolted connections
Es02 Project Legend: F v,Ed = the design shear force per bolt for the ultimate limit state F v,Rd = the design shear resistance per bolt F b,Rd = the design bearing resistance per bolt F v,Ed,ser = the design shear force per bolt for the serviceability limit state F s,Rd,ser = the design slip resistance per bolt at the serviceability limit state F t,Ed = the design tensile force per bolt for the ultimate limit state F t,Rd = the design tension resistance per bolt B p,Rd = the design punching shear resistance of the bolt head and the nut A = the gross cross-section area of bolt A s = the tensile stress area of the bolt or of the anchor bolt d = diameter of the bolt Appendix B – bolted joints
Es02 Project Positioning of the holes of bolts: Appendix B – bolted joints
Es02 Project Design resistance for individual bolt subjected to shear and/or tension Appendix B – bolted joints