Investigation of U-head rotational stiffness in formwork supporting scaffold systems

In a steel supporting scaffold system, timber bearers impose a restraint on the rotation of scaffold U-head. This rotational restraint can be modelled by a rotational spring in structural analysis. To quantify the moment-rotation response of the U-head-timber bearer interface, a series of U-head sub-assembly tests were conducted, with a wide variation of parameters including applied load level, U-head configurations, and moisture content ratios of the timber bearers and joists. The relationship between the rotational stiffness and applied load is determined. A simplified procedure is proposed to implement this rotational restraint in nonlinear finite element analysis. (C) 2017 Elsevier Ltd. All rights reserved.