考虑材料高温蠕变的螺纹副轴向承载分布规律

Axial Load Distribution Law of High Temperature Thread Pair Considering Material Creep

为了研究高温蠕变对螺纹副承载的影响,分别在常温、250、300、350℃下对铝合金试样进行单轴拉伸蠕变试验,通过试验数据拟合得到不同温度下铝合金的时间硬化蠕变模型参数;基于ABAQUS建立螺纹副承载分布有限元模型,描述螺栓连接组合结构在高温环境下的工作情况,研究螺纹副材料在线弹性、塑性、蠕变情况下的承载分布.结果表明:螺栓连接组合结构在高温环境下工作时,被连接件铝合金材料发生蠕变,导致螺纹副1号螺纹牙受轴向载荷大幅减少;考虑材料线弹性后,1号螺纹牙承载比例为22.88%~23.15%;考虑材料塑性后,1号螺纹牙承载比例为20.80%~20.95%;考虑材料蠕变后,1号螺纹牙承载比例为20.65%~21.02%;考虑材料塑性和蠕变后,1号螺纹牙承载比例有所降低,所有螺纹牙所受轴向载荷趋于平均.

In order to study the effect of high temperature creep on thread load,uniaxial tensile creep tests were conducted on aluminum alloy specimens at normal temperature,250℃,300℃,and 350℃.The time-hardening creep model parameters of the aluminum alloy at different temperatures were obtained by fitting the test data.To more accurately describe the working condition of a bolted connection structure in a high-temperature environment,a finite element model of the bolted connection structure was established using ABAQUS,and the effects of linear elasticity,plasticity,and creep on the load distribution were studied.The results show that when the bolted connection structure works in a high-temperature environment,the aluminum alloy material of the connected component creeps and the axial load of the No.1 thread thus decreases greatly.Considering the material elasticity,the bearing ratio of the No.1 thread is between 22.88%and 23.15%.Considering the material plasticity,the bearing ratio of the No.1 thread is between 20.80%and 20.95%.Considering the material creep,the bearing ratio of the No.1 thread is between 20.65%and 21.02%.Considering the plasticity and creep of the material,the bearing ratio of the No.1 thread is reduced,and the axial load of all teeth tends to be average.