組立柱のタイロッドのねじ締結軸力解析

抄録

This paper deals with the analysis of axial loads in the tie rods to clarify the relationship between the axial loads and the ordinal number of the nuts of built-up columns which are applied the fastening torque. First of all, an experimental analysis of the change of axial loads is performed while fifteen cylindric parts of the built-up columns of spiral staircase are assembled. Next, a numerical analysis of axial loads in the first tie rod is made by the finite element method. The results are summarized as follows. (1) As the ordinal number of the nuts increases, the values of axial loads in the tie rods become higher, and as a result, the first tie rod gets the maximum load. (2) The value of axial load in the first tie rod becomes higher as the set up value of fastening torque increases and the ordinal number of the nuts increases. (3) The calculated values of axial loads in the first tie rod mostly agree with the experimental values. (4) When a set up value of the fastening torque takes 107.9, 147.1 or 186.3 N·m, the values of additional axial loads in the first tie rod decrease at a constant rate as the ordinal number of the nuts increases. (5) The proposed method used in this paper can generally analyze the actual change of axial loads in the tie rods sufficiently and accurately for the practical usage.