|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥1,100,000 (Direct Cost : ¥1,100,000)
This research deals with the characteristics of bolted joints under thermal changes or subjected to heat conduction. The bolted joints, which were consisted of rectangular thick plates or hollow cylinders made of aluminum alloy and were fastened at room temperature by a steel bolt, were examined. The following results are obtained :
(1) The temperature distributions in the bolted joints are analyzed using the finite difference method. Then, the method for estimating the increase in axial bolt force is proposed by using the temperature distributions.
(2) The effects of the ratio w/a of the plate thickness to the bolt hole diameter in the rectangular thick plate on axial bolt force, are clarified by numerical calculations in the case where clamped parts are rectangular thick plates and hollow cylinders. It is shown that an increment of the axial bolt force increases with an incerase of the ratio b/a.
(3) When bolted joints of rectangular thick plates and hollow cylinders are put in a furnace, the increase in axial bolt force is measured using strain gauges for high-temperature use. In the case where clamped parts are hollow cylinders, the increment in axial bolt force and the temperature distribution are measured.The analytical results are in fairly good agreement with experimental ones.
(4) It is seen that the increment in axial bolt force of bolted joints under thermal changes is larger than that caused by static external load.