Stochastic Thermal Modal Characteristics of a Plate with Free Boundary conditions Induced by a Random Heating Position Based on a Thermally Coupled Model
Stochastic Thermal Modal Characteristics of a Plate with Free Boundary conditions Induced by a Random Heating Position Based on a Thermally Coupled Model
复制标题
DOI：
10.1016/j.jsv.2023.117581
复制
发表时间：
2023-01
影响因子：
4.7
通讯作者：
Yu-Jia Hu;Lei Hu;Wei-dong Zhu;Haolin Li
中科院分区：
文献类型：
--
作者：
Yu-Jia Hu;Lei Hu;Wei-dong Zhu;Haolin Li
温度对结构的热模态特性有着重要的影响，特别是温度分布的不确定性使得结构的热模态特性更加复杂。这种不确定性也使得确定性预测结果与高温下热模态实验结果有很大偏差，甚至随温度的变化趋势也会不同。基于热耦合模型，研究了由随机加热位置引起的自由边界条件下板的随机热模态特性。首次得到了双参数高斯热源作用下平板的温度场分布。基于热耦合本构关系理论建立了板的热耦合动力学模型，并采用微分求积法求出了板的模态参数。提出了一种基于改进Bootstrap方法和折叠正态分布的小样本统计分析方法，研究了随机加热位置下板的随机热模态特性，包括固有频率的概率密度函数及其置信区间。相关研究对热力学实验结果的可靠性评价、实验结果与理论结果的误差分析具有重要意义。
Temperature has significant effects on thermal modal characteristics of a structure; especially, its distribution uncertainty makes thermal modal characteristics to be more complicated. Such uncertainty also makes definitely predicted results greatly deviate from thermal modal experimental results at high temperature, and even their change trends with temperature would be different. In this work, stochastic thermal modal characteristics of a plate with free boundary conditions induced by a random heating position are studied based on a thermally coupled model. Temperature field distributions of the plate under two-parameter Gaussian heating sources are first obtained. A thermally coupled dynamic model of the plate is then established based on a thermally coupled constitutive relation theory, and its modal parameters are obtained by a differential quadrature method. A statistical analysis method with a small sample based on an improved Bootstrap method and folded normal distribution is proposed to study stochastic thermal modal characteristics of the plate induced by a random heating position, which includes probability density functions of natural frequencies and their confidence intervals. Relevant research will be of great significance to reliability evaluation of thermodynamic experimental results, and error analysis between experimental and theoretical results.