Finite Element Analysis of the Thermal and Mechanical Behaviors of a Bolted Joint
Finite Element Analysis of the Thermal and Mechanical Behaviors of a Bolted Joint
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DOI：
10.1115/1.2042477
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发表时间：
2005-11
影响因子：
1
通讯作者：
T. Fukuoka
中科院分区：
文献类型：
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作者：
T. Fukuoka
采用轴对称有限元方法分析了螺栓接头在热载荷作用下的力学和热行为，考虑了界面接触热阻和小间隙热流的影响，以准确评估螺栓预紧力的变化。可望为压力容器、内燃机、汽轮机、燃气轮机等关键结构的强度估算提供一种有效的方法。文中提出了计算常见工程材料界面热接触系数的空气经验公式。在本研究中，通过定义表观热接触系数，给出了一个简单的计算通过小间隙的热流量的公式。在此基础上，通过将这两种热接触系数引入有限元公式，建立了一种能够准确分析螺栓联接热性能和力学性能的数值方法。利用编制的有限元程序计算表明，节点构件之间的线膨胀系数只有很小的差异对螺栓预紧力的变化有显著影响。通过实验验证了数值方法的有效性。
Mechanical and thermal behaviors of the bolted joint subjected to thermal load are analyzed using axisymmetric FEM, where the effects of thermal contact resistance at the interface and heat flow through small gap are taken into account in order to accurately evaluate the variations of bolt preloads. It is expected that the numerical procedure proposed here provides an effective means for estimating the strength of such critical structures as pressure vessels, internal combustion engines, steam and gas turbines, etc. Air experimental equation that can compute the thermal contact coefficient at the interface composed of common engineering materials has been proposed in the previous paper. In this study, a simple equation for evaluating the amount of heat flow through small gap is shown by defining apparent thermal contact coefficient. Accordingly, a numerical approach has been established, which can accurately analyze the thermal and mechanical behaviors of a bolted joint, by incorporating the two kinds of thermal contact coefficients into FE formulation. By use of the FE code thus developed, it is shown that only a slight difference in coefficients of linear expansion among the joint members significantly affects the variations of bolt preloads. The validity of the numerical approach is demonstrated by experimentation.