FD+E Weld Challenge 1: T-Tube Welded, A36 Steel

Fatigue Design and Evaluation Committee members: T.Cordes, M.El-Zein, J.Deere
Web Page: https://fde.uwaterloo.ca/Fde/CaseStudies/Weld1_Ttube/weld1_Ttube.html

Data Reference:
Contributed to Fatigue Design and Evaluation committee by J.Deere.
Tested at J.Deere Moline, U.of Illinois, Ford Sci. Res Lab,

Invitation (Feb. 2003): Invitation to FDE from J.Deere (txt file)

Fig. 1: Specimen


The material is an ASTM A36 structural steel in the form rectangular tubes.
Yield was given as "about 50 ksi"

Note that the original stress-strain life crack initiation data file used
by many of the simulators is not available.   The files indicated below are
felt to be reasonably similar.

Crack Initiation:
Strain controlled ASTM E606 axial specimen test results for ASTM  A36 steel 
can be found

Note that these are not tests from the same tube material, but were collected
from other studies.

Crack propagation  
The da/dN vs ΔK data for A36 steel was not available during the original
tests and simulations, but became available later.  It was collected from presentations
and papers (Refs.: [1-4]) and is plotted in figure 2.

Fig. 2 : Collected A36 and similar low carbon steel da/dN vs ΔK data.


(Click figure to enlarge)
Fig. 3 : Component Geometry.

Notes on section properties available
(Click figure to enlarge)
Fig. 4 : Section properties

Load History

Fig. 5:
(June 2014: There is some question as to the lever arm being 12.5", TBD)


Twelve Samples were tested to totally reversed (R=-1) 
constant amplitude load control input
at  load levels:

R= -1.0 :      +-4000 Lbs (+- 17.8 kN), 

Specimens were also tested at  R== 0

R=  0   :    Pmax=  +4000  Pmin= 0   lbs


Test Results

# Experimental test results

# R= -1.0

Fig. 6: Test results for R= -1.0, Pmax=4000 Pmin=-4000 lbs.


  1. Dindinger, P., "A36 Strain Life Fatigue Test Data," Fat.Des.and Evaluation Comm. Meeting, Oct.18,2011, Stork Technimet, 3200 South 166th St, New Berlin, WI

  2. Neuman, J., "Fatigue Crack Growth Rate Behavior of A36 Steel using ASTM Load-Reduction and Compression Precracking Test Methods," Fat.Des.and Evaluation Comm. Meeting, Oct.18,2011, Stork Technimet, 3200 South 166th St, New Berlin, WI

  3. El-Haddad, M.H. "A Study of the Growth of Short Fatigue Cracks Based on Fracture Mechanics," Ph.D. Thesis, U.of Waterloo, Canada, Aug. 1978.

  4. Klingerman, D.J., K.H. Frank, J.W.Fisher, " Fatigue Crack Growth in A36 Steel," Lehigh Univ., Fritz Engr. Lab Rep. No. 358.31, May 1971.

  5. Miller, G.A. and H.S.Reemsnyder, "Strain-Cycle Fatigue of Sheet and Plate Steels I: Test Method Development and Data Presentation," SAE Paper 830175, Detroit MI, Feb28-Mar.4, 1983

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