Skip to main content
SpringerLink
Log in

Fabrication aspects in the optimum design of welded structures

  • Originals
  • Published:
Structural optimization Aims and scope Submit manuscript

Abstract

A brief survey of selected literature shows that fabrication aspects play an important role in the economic design of welded structures. Fabrication costs and production requirements should be considered in the optimum design procedure.

In a detailed numerical example some optimal solutions are determined for a simple box beam having transverse diaphragms and carrying a fluctuating load. In the objective function the material and fabrication costs are taken into account. The cost function formula enables the investigation of structural solutions for wide ranges of cost factors.

Constraints on fatigue strength, local buckling of plate elements, shear stress and deflection are considered. Based on the active constraints, the cost function may be expressed as a function of the beam height as the main variable. The minimum cross-sectional area, volume and cost designs are calculated.

Concerning the fillet welds of the transverse diaphragms two solutions are considered: (1) without post treatment with a lower fatigue strength; (2) with post toe burr grinding with improved fatigue strength. In the second case the cost of post treatment is also included in the cost function.

A comparison of the above solutions shows that the post treatment of transverse fillet welds may be economic despite of the additional cost.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

A :

cross-sectional area

A f :

cross-sectional area of a flange

a w :

fillet weld size

b :

beam width

c 1 , c2 :

distances of diaphragms from the support

E :

modulus of elasticity

G = ρV :

mass

h :

web height

I x :

moment of inertia

K :

total cost

K m , K f :

material and fabrication cost, respectively

k m , k f :

material and fabrication cost factor, respectively

L :

span length

L w :

weld length

M :

bending moment

N :

number of cycles

n :

number of diaphragms

n 1 :

number of diaphragms with post treated welds

p :

intensity of normal load

Q :

shear force

S x :

statical moment

T :

time

t f , t w /2:

flange and web thickness, respectively

V :

volume

W x :

section modulus

W 0 :

required section modulus

ω :

deflection

β :

limiting plate slenderness of webs

δ :

difficulty factor

δ f :

limiting plate slenderness of the compression flange

ϑ = k f /km :

ratio of cost factors

κ :

number of structural elements

v :

Poisson's ratio

ρ :

density

σ :

normal stress

σ f :

fatigue strength

τ :

shear stress

τ f :

fatigue strength in shear

τ w :

shear stress in welds

References

  • Bo, G.M; Capurro, P.M.; Daddi, I. 1974: Sulla razionalizzazione dei profili ad I per flessione e taglio.Construzioni Metalliche 26, 102–112

    Google Scholar 

  • Farkas, J. 1984a:Optimum design of metal structures. Budapest: Akademiai Kiado; Chichester: Ellis Horwood

    Google Scholar 

  • Farkas, J. 1984b: Economy of the application of higher strength steels in compression members of welded square box cross-section and in hybrid I-beams.Proc. 2nd Int. Conf. Metal Structures Vol.3 (held in Gdansk), pp.77–84

    Google Scholar 

  • Farkas, J. 1984c: Economy achieved by using higher strength steels in trusses welded fron square hollow sections. Welding of tubular structures.Proc. 2nd Int. Conf. (held in Boston), pp. 137–144. Pergamon Press: Oxford

    Google Scholar 

  • Farkas, J. 1988a: Economy of higher strength steels in overhead traveling cranes with double-box girders.J. Const. Steel Research 6, 285–301

    Google Scholar 

  • Farkas, J. 1988b: Economic design of longitudinally stiffened steel plates under uniaxial compression. In:Stability of steel structures. Vol. 2, pp. 625–631. Budapest: Akademiai Kiado

    Google Scholar 

  • Farkas, J. 1988c: Consideration of fabrication costs in the optimum design of welded tubular trusses.IIW-Doc. XV-677-88

  • Farkas, J. 1990: Minimum cost design of tubular trusses considering buckling and fatigue constraints. In: Niemi, E.; Mäkeläinen, P. (eds.)Tubular structures, pp. 451–459. London: Elsevier

    Google Scholar 

  • Gábry, G. 1989: Corrosion fatigue of welded joints.Proc. 8th Int. Conf. Metal Structures. Vol.1 (held in Gdansk), pp. 54–61

    Google Scholar 

  • Gorenc, B.E. 1985: Design of welded steelwork details for strength, serviceability and cost effectiveness.Australian Welding J. 50, 15–19

    Google Scholar 

  • Hicks, J. 1988: The interface between design and fabrication in welded products.Welding and Metal Fabrication, 222–224

  • Karsan, D.I.; Valdivieso, J.B.; Suhendra, R.: An economic study on parameters influencing the cost of deepwater fixed platforms.Proc. 18th Annual Offshore Technology Conf. Vol. 4 (held in Houston, Texas), pp. 79–93

  • Kuo, C.; MacCallum, K.J.; Shenoi, R.A. 1984: An effective approach to structural design for production.Trans. Roy. Inst. Naval Architects (RINA), 33–50

  • Pahl, G.; Beelich, K.H. 1982: Kostenwachstumsgesetze nach Ähnlichkeitsbeziehungen für Schweissverbindungen.VDI-Berichte Nr.457, pp. 129–141, Düsseldorf

    Google Scholar 

  • Ricker, D.T. 1988: Value engineering and steel economy.Proc. 1988 National Steel Construction Conf. (held in Miami, Fl), pp. 1–23. Chicago: American Institute of Steel Construction

    Google Scholar 

  • Tordoff, D.T. 1985:Steel bridges. The practical aspects of fabrication which influence efficient design. London: British Constructional Steelwork Assoc.

    Google Scholar 

  • Wiebeck, E. 1986: Some aspects of design for production of double-walled ship structures.Wiss. Zeitschrift Univ. Rostock 35 Naturwiss. Reihe, Heft9, 79–82

    Google Scholar 

  • Winkle, I.E.; Baird, D. 1986: Towards more effective structural design through synthesis and optimization of relative fabrication costs.Trans. Roy. Inst. Naval Architects (RINA) 128, 313–336

    Google Scholar 

  • Woodley, C.C. 1983: Practical applications of weld toe grinding. In:Improving the fatigue strength of welded joints, pp. 19–22. Abington, UK: The Welding Institute

    Google Scholar 

  • 1982: Design recommendations for cyclic loaded welded steel structures.Welding in the World 20, 153–165

  • 1983:Improving the fatigue strength of welded joints. Abington, Cambridge, UK: The Welding Institute

  • 1987: Recommendations pour la vérification à la fatigue des structures en acier.Construction Europénne la Construction Métallique. Construction Métallique 24, 1–33

Download references

Author information

Authors and Affiliations

  1. Dept. Materials Handling Equipments, University of Miskolc, H-3515, Miskolc, Egyetemváros, Hungary

    J. Farkas

Authors
  1. J. Farkas
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Farkas, J. Fabrication aspects in the optimum design of welded structures. Structural Optimization 3, 51–58 (1991). https://doi.org/10.1007/BF01743489

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01743489

Keywords

Search

Navigation