A Stress Analysis of Bolted Joint under Various Boundary Conditions

本文研究了热传导作用下螺栓连接的特性。螺栓连接是由铝合金制成的矩形厚板或空心圆柱体组成，并在室温下用钢螺栓固定。结果表明：(1)采用有限差分法对螺栓连接内的温度分布进行了分析。然后，提出了利用温度分布估算轴向锚杆力增量的方法。(2)通过数值计算，阐明了矩形厚板中板厚与螺栓孔直径之比w/a对轴向螺栓力的影响。结果表明，轴向锚杆力的增加随着b/a比的增加而增加。(3)将矩形厚板与空心圆筒的螺栓接头放入炉内，采用高温应变片测量螺栓轴向力的增加情况。在夹紧零件为空心圆柱体的情况下，测量了轴向螺栓力的增量和温度分布。分析结果与实验结果吻合较好。(4)可以看出，热变化作用下螺栓连接轴向螺栓力的增量大于静外载荷作用下螺栓连接轴向螺栓力的增量。

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.