000019430 001__ 19430
000019430 005__ 20170118182318.0
000019430 04107 $$aeng
000019430 046__ $$k2017-01-09
000019430 100__ $$aNakagomi, Tadao
000019430 24500 $$aSeismic Performance of Cold-Formed Square-Hollow-Section Steel Column To Through-Diaphragm Welding Connection Using a 25 Degrees Narrow Groove

000019430 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000019430 260__ $$b
000019430 506__ $$arestricted
000019430 520__ $$2eng$$aThe welding groove angle and is an important factor that affects the weld quality when welding steel members. Currently, a welding groove angle of 35° is normally used by Japanese fabricators. However, a 25° narrow-groove welding method can improve the production efficiency and reduce the environmental impact. From the previous research results, a welding with a 25° narrow groove is considered to be feasible. However, full-scale tests for this type of groove have not carried out and the performance of a connection welded using a 25° narrow groove has not been evaluated. In this study, we conducted a series of three-point bending tests on a cold-formed square-hollow-structural-section (SHSS) steel column to a throughdiaphragm welding connection by using a 25° narrow groove. Subsequently, we investigated the deformation capacity of the welded connection. The column of the test specimen was a steel rectangular pipe (HSS550x550x32: BCP325) formed by a cold-press forming process. The through-diaphragm of the specimen was made of a steel plate (PL36: SN490C). The length of the support span of the test specimen was 4 m, and the welding groove angle of the test specimen was 25°. A welding robot was used to weld the cold-formed SHSS column and the through-diaphragm. In addition, since the shape of the welded toe has a significant influence on the deformation capacity of the welded connection, the weld toe of one of the specimens was polished using a hand grinder to relieve the stress concentration at the weld toe. The results obtained in this study are as follows: (1) The deformation capacity of a cold-formed SHSS column to a through-diaphragm welding connection by using a 25° narrow groove is comparable to or higher than that obtained in the previous tests conducted using a 35° standard groove. (2) In all the test specimens, ductility crack initiation occurred at the weld toe, which did not progress to the heat-affected zone. The crack path was located at the corners of the column. The ductile crack grew, and finally, it induced a brittle fracture in the base material of the column. (3) Even when the welding defect existed in the first layer of the column corners, brittle fracture did not occur at the welding defects. (4) Relieving the stress concentration at the weld toe with grinder finishing delayed ductile crack initiation, thus improving the deformation capability of the welded connection of the cold-formed SHSS column.

000019430 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000019430 653__ $$acyclic bending loading, cold-formed rectangular steel column, welding robot, plastic deformation capacity

000019430 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000019430 720__ $$aNakagomi, Tadao$$iMinami, Susumu$$iHattori, Kazunori
000019430 8560_ $$ffischerc@itam.cas.cz
000019430 8564_ $$s773002$$uhttps://invenio.itam.cas.cz/record/19430/files/3601.pdf$$yOriginal version of the author's contribution as presented on USB, paper 3601.
000019430 962__ $$r16048
000019430 980__ $$aPAPER