Issue 41

Z. Li et alii, Frattura ed Integrità Strutturale, 41 (2017) 378-387; DOI: 10.3221/IGF-ESIS.41.49 386 The first group of specimens are CH-2, CH-4 and CH-5, all of which are made of the same material Q345; however, the three specimens differ in width-thickness ratio at the flange, respectively 14.5, 24.5 and 41.2. Figure 16: The relationship between the peak residual tensile stress and width-thickness ratio The difference between the third of specimens is also presented in the above figure. For specimens of the same material grade, the peak value of residual stress at the flange plunges with the increase of the width-thickness ratio. In particular, the peak residual stress falls all the way from 564.06MPa in CH-2, 388.09MPa in CH-4 to 31.16MPa in CH-5. The increase in width-thickness ratio means the member is getting thinner and the sectional size (width) is getting larger. The test results reveal the weakening of the effect of residual welding stress on member behavior and the shrinkage of peak residual stress in the cross-section. In other words, the width-thickness ratio has an insignificant effect on the distribution of residual stress in welded I-section members. Therefore, it is safe to use large I-section members beyond the limits on width-thickness ratio. C ONCLUSION ollowing the blind-hole drilling method, this paper explores the effect of width-thickness ratio on the behavior of I- section members. The conclusion are as follows: (1) It is safe to use large I-section members beyond the limits on width-thickness ratio. (2) For a given width-thickness ratio, the higher the yield strength, the larger the peak value of the residual stress. (3) For structural members of the same grade, the larger the width-thickness ratio, the smaller the peak residual stress. A CKNOWLEDGEMENTS he research of this paper is made possible by the generous support from the Special Fund for Construction of Key Disciplines in Shaanxi Province, China (No.: E01001, E01003), key research project of Chongqing Water Resources and Electric Engineering College (No.: K201615), and the Science and Technology Project Affiliated to the Education Department of Chongqing Municipality (No.: KJ1603604). R EFERENCES [1] The Ministry of Construction of the People's Republic of China, GB 50017-2003 Code for Design of Steel Structures, Beijing: China Planning Press——Steel structure design specification, GB 50017-2003, 2013. [2] Teng, T.L., Fung, C.P., Chang P.H., Yang W.C., Analysis of residual stresses and distortions in T-joint fillet welds, Int. J. Pres. Ves. Pip., 78 (2001) 523-538. DOI: 10.1016/S0308-0161(01)00074-6. F T