Failure Modes and Limit States of Longitudinal Plate to RHS Connections

摘要

The use of Rectangular Hollow Sections (RHS) in different structures has been expanded dramatically, and longitudinally-oriented plates have been used widely to connect braces and other attachments to RHS members. Since plate-to-RHS connections are very flexible, some factors have to be considered in the design of this connection type, such as large deformations on connecting faces and non-uniformly distributed stresses in plates. The existence of an axial load on an RHS member also affects the strength of a plate connected to the RHS member. Based on an investigation of different failure modes of plate-to-RHS connections under different loading cases, a tentative design method is proposed for the connections. Two deformation limits are used to control the deformation of the connecting face in an RHS member. The deformation under the ultimate load is limited to 3% of the RHS member width and the deformation under the service load is limited to 1% of the RHS member width. The effective width of the plate, effective length of the welds, and the influence of the axial load in the RHS member should also be considered. Four 90° longitudinal plate-to-RHS column connections have been tested under different axial loads on the column. The connections were tested to rupture and the load-displacement behaviour of the column faces and stress distributions in the plates were obtained. The test results generally confirm the proposed design method for plate effective width and connection to the column face.