final project 2010 e. tarallo, g. mastinu politecnico di milano, dipartimento di meccanica
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Final Project 2010
E. Tarallo, G. Mastinu
POLITECNICO DI MILANO, Dipartimento di Meccanica
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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.
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3The considered frame
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4The considered frame
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5The considered frame
* All the drawings have been put in the website as pdf formats
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6Loads
A
B
C
D
Type A(kN) B(kN) C(kN) D(kN)
1 250 250 150 100
2 250 -250 150 100
3 250 250 -150 -100
*All the directions in this figure are POSITIVE*The position of the forces A and B should be extracted from the drawings
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7Different 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)
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8Appendix 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 throatnormal stress parallel to the axis of weldshear stress perpendicular to the axis of weldshear 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.
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• 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 seethe standard
• For other criteria see stdCNR 10011
Appendix A – welded joints
2
2||
22 3Mw
uf
2
9.0
M
uf
uf
w2M
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10Appendix 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
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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
Appendix B – bolted joints
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Positioning of the holes of bolts:
Appendix B – bolted joints
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Design resistance for individual boltsubjected to shear and/or tension
Appendix B – bolted joints