Final Project 2010 E. Tarallo, G. Mastinu POLITECNICO DI MILANO, Dipartimento di Meccanica

1. Final Project 2010 E. Tarallo, G. Mastinu POLITECNICO DI MILANO, Dipartimento di Meccanica

2. Summary • 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.

3. The considered frame

4. The considered frame

5. The considered frame 5 * All the drawings have been put in the website as pdf formats

6. Loads A B C D *All the directions in this figure are POSITIVE *The position of the forces A and B should be extracted from the drawings

7. Different Analysis • Modeling: • Beam Elements (use constant section) • Shell Elements (use constant thickness) • Solid Elements (check welded or bolted joints) • Analysis: • Static general (use constant loads and right boundary) • Frequency linear perturbation (find first 5 natural frequency) • Dynamic, implicit (use sinusoidal input of amplitude equal to static load and variable frequency – look at phase problem)

8. 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.

9. Appendix A – welded joints • 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 1.25. • For simplified criteria see • the standard • For other criteria see std • CNR 10011

10. 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: fyb (yeld stress) fub (ultimate stress) • Category of bolted connections

11. Appendix B – bolted joints Legend: • Fv,Ed= the design shear force per bolt for the ultimate limit state • Fv,Rd = the design shear resistance per bolt • Fb,Rd = the design bearing resistance per bolt • Fv,Ed,ser = the design shear force per bolt for the serviceability limit state • Fs,Rd,ser = the design slip resistance per bolt at the serviceability limit state • Ft,Ed= the design tensile force per bolt for the ultimate limit state • Ft,Rd = the design tension resistance per bolt • Bp,Rd = the design punching shear resistance of the bolt head and the nut • A =the gross cross-section area of bolt • As = the tensile stress area of the bolt or of the anchor bolt • d = diameter of the bolt

12. Appendix B – bolted joints Positioning of the holes of bolts:

13. Appendix B – bolted joints • Design resistance for individual bolt • subjected to shear and/or tension