Steel Design BCN 3431

Steel Design BCN 3431

ENCE 710 Design of Steel Structures IV. COMPOSITE STEELCONCRET CONSTRUCTION C. C. Fu, Ph.D., P.E. Civil and Environmental Engineering Department University of Maryland Introduction Following subjects are covered: Composite Action Effective Width Nominal Moment Strength Shear Connectors, Strength and Fatigue Formed Steel Deck

Reading: Chapters 16 of Salmon & Johnson AISC LRFD Specification Chapters B (Design Requirements) and I (Design of Composite Members) 2 Composite Action 3 Effective Width AISC-I3 1. Interior BE L/4 BE b0 (for equal beam spacing)

2. Exterior BE L/8 + (dist from beam center to edge of slab BE b0/2 + (dist from beam center to edge of slab) 4 Nominal Moment Strength Nominal Moment Strength of Fully Composite Section (AISC 14th Edition Art. I3.2a) 1.

hc / t w p 3.76 / E F yf Mn = based on plastic stress distribution on the Composite Section; b = 0.9 2. hc / t w p 3.76 / E

F yf Mn = based on superposition of elastic stresses, considering the effect of shoring; = 0.9 5 Plastic Stress Distribution Case 1 (if a ts): S & J Eq. (16.7.1 to 5) Case 2 (if a > ts): S & J Eq. (16.7.6 to 10)

6 Shear Connectors 7 Shear Variation V = Cmax = 0.85fcbEts V = Tmax =AsFy N = Cmax/Qn or Tmax/Qn Whichever is smaller 8 Nominal Strength Qn

Qn = 1. Headed Steel Stud (AISC Eq. I8-1) Qn 0.5 Aw 2. Connectors 2) f c ' E c Rg R p Asc Fu Channel

(AISC Eq. I8- Qn 0.3(t f 0.5t w ) Lc f c ' Ec 9 Nominal Strength Qn 10 Connector Design Fatigue Strength nZ r I 6.10.7.4.1b-1)

Vsr Q (AASHTO LRFD Eq. Zr = d 1) (AASHTO LRFD Eq. 6.10.7.4.2- p 2 5.5 d 2/2; where = 34.5 4.28 log N (AASHTO LRFD Eq. 6.10.7.4.22)

Exampl e: 11 Composite Column Section (rolled steel shape encased in concrete) AISC I2.1. Encased Composite Columns AISC I2.2. Filled Composite Columns (Ref: Separate handout with examples.) 12 Composite Column Section (rolled steel shape encased in

concrete) Using Effective Section Properties (I2-4, 5 & 6) P0 As Fy Asr Fyr 0.85 Ac f ' c Pe1 2 EI eff K1 L 2 EI eff E s I s 0.5 E s I se C1 E c I c 13 Filled Composite Column Example

AISC I2-2b (a)Compact (b)Noncompa ct (c)Slender 14 Filled Composite Column Example For compact sections Ac = bfhf+(r-t)r-t)2+2bf(r-t)r-t)+2hf(r-t)r-t) Ac = (r-t)8.5 in.)(r-t)4.5 in.) + (r-t)0.375 in.)2 + (r-t)8.5 in.)(r-t)0.375 in.) +

2(r-t)4.5 in.)(r-t)0.375 in.) = 48.4 in.2 b1h12 2(b2 )(h22 ) 8 (r t ) 2 h2 4(r t ) 2 Ic 2(r t )( ) 2( )( ) 111in.4 12 12 8 9 2 2

3 P0 As Fy Asr Fyr 0.85 Ac f ' c P0 = (r-t)10.4 in.2)(r-t)46ksi) + 0.85(r-t)48.4 in.2)(r-t)5 ksi) = 684kips EI eff E s I s 0.5 Es I se C 3 Ec I c EIeff = (r-t)29,000 kis)(r-t)61.8 in.4) + (r-t)0.90)(r-t)3,900 ksi)(r-t)111 in.4) = 2,180,000 kip-in.2 15 Filled Composite Column Example Pe1 2 EI eff

K1 L 2 Pe = 2(r-t)2,180,000 kip-in.2)/(r-t)1.0(r-t)14 ft)(r-t)12 in./ft))2 = 762 kips kips = 0.898 2.25 P0/Pe = 684 kips/762 p0 / Pe 0.898 Pn P0 0.658 (684kips) 0.658 470kips

cPn = 0.75(r-t)470 kips) = 353 kips > 336 kips o.k. 16

Recently Viewed Presentations

  • 2-6-03 Urogenital Development II  & Sex Determination Greg

    2-6-03 Urogenital Development II & Sex Determination Greg

    However, differences at the genetic and microscopic levels are already Apparent. Female nuclei contain a Barr body, which is an inactivated X chromosome Male embryos show gene expression of some Y specific proteins such as SRY, testis determining factor, and...
  • Electronic Detection of Plagiarism - Aberdeen Scotland

    Electronic Detection of Plagiarism - Aberdeen Scotland

    Turnitin UK: Electronic Plagiarism Detection By Catherine Ogilvie Department for the Enhancement of Teaching, Learning and Assessment (DELTA) What is plagiarism? plagiarize or plagiarise verb (plagiarized, plagiarizing) tr & intr to copy (ideas, passages of text, etc) from someone else's...
  • Title of Presentation - Alliance

    Title of Presentation - Alliance

    Independent (Non-SMO) entities in California, Texas and Florida comprise the Alliance. Combined 1,000+ clinical trials conducted, phases I-IV. Central IRB. Large patient databases, affiliated medical practices and proven recruitment methods
  • Geen diatitel

    Geen diatitel

    Next read the quiz script - and make notes of new vocabulary. Finish off by the 'post-listening' task(s). Make prints of your answers as proof for your portfolio. You would like to get more practice with listening to American or...
  • Evidence review: climate change and social justice Evidence

    Evidence review: climate change and social justice Evidence

    From Gough et al. 2011 . The distribution of total greenhouse gas emissions by households in the UK, CASE LSE. The unequal distribution of. ... more fuel efficient fleets and electric vehicles are not a useful tool for the climate...
  • World War I The Causes

    World War I The Causes

    Title: World War I The Causes Author: Dave Last modified by: kimr Created Date: 4/1/2007 9:34:03 PM Document presentation format: On-screen Show (4:3)
  • Distributed Processing, Client/Server, and Clusters

    Distributed Processing, Client/Server, and Clusters

    Communication Management and Distributed Processing, ... class B and class C IP to physical address translation network hardware recognizes physical addresses Address Resolution Protocol (ARP) to obtain the translation each host caches a list of IP-to-physical translation which expires after...
  • PBIS AT HOME - internet.savannah.chatham.k12.ga.us

    PBIS AT HOME - internet.savannah.chatham.k12.ga.us

    How do I use PBIS at home? Research shows that when behavior expectations are clearly established and taught in the home, children's problem behavior is prevented or reduced. ... Create a behavior matrix that establishes expected behaviors for essential routines...