螺栓拉弯失效的贝叶斯特征学习与不确定性预测

BAYESIAN-DRIVEN FEATURE LEARNING AND UNCERTAINTY PREDICTION OF BOLT FAILURE BEHAVIOR UNDER COMBINED TENSILE AND BENDING LOADS

  • 摘要: 螺栓连接作为大型装备领域应用最广泛的连接形式,该类结构失效模式多样且存在显著的拉弯耦合效应,导致传统数值分析方法(如有限元法)在开展失效行为预测与承载能力不确定性量化时,面临计算效率低下、失效判断精度不足等严峻挑战。为此,本研究提出了一种贝叶斯驱动特征学习(Bayesian-driven feature learning, BDFL)方法,实现了对螺栓失效行为及其响应分布的精准预测。首先,通过力学分析发现了螺栓轴向力曲线的拐点位置与结构失效行为存在显著关联规律,进而利用贝叶斯集成算法(Bayesian estimator of abrupt change, seasonal change, and trend, BEAST)实现了对关键拐点自动识别。随后,结合监督代理模型与无监督主成分分析(principal component analysis, PCA)对提取的拐点集合进行特征降维。最终,以降维后的主成分为输入特征,以试验测得的失效载荷为响应变量,构建嵌套随机克里金模型(nested stochastic Kriging, NSK)进行螺栓失效行为预测。数值结果表明:与传统静态模型和Johnson-Cook模型相比,所提方法在高保真、低保真及组合模型中均展现出更优预测精度。该方法通过机器学习融合仿真与试验数据,在不增加计算成本的前提下显著提升了仿真精度,为大型装备连接结构的可靠性设计提供了新思路。

     

    Abstract: As the most widely used connection method in large-scale equipment, bolted connections exhibit diverse failure modes and significant tension-bending coupling effects, posing severe challenges such as low computational efficiency and insufficient accuracy of failure criteria for traditional numerical methods (e.g., finite element method) when performing failure behavior prediction and bearing capacity uncertainty quantification. In this paper, a Bayesian-driven feature learning (Bayesian-driven feature learning, BDFL) method is proposed. Specifically, it is found that the inflection points of the bolt axial force curve are critical for predicting failure behavior, so a Bayesian-based method is used for inflection point recognition. Then, a dimension reduction process combining the supervised surrogate model and unsupervised principal component analysis is proposed. Taking the above variables and failure loads as input data, the nested stochastic Kriging model is applied for uncertainty analysis and prediction. Compared with the traditional static model and Johnson-Cook model, the results demonstrate that the proposed method can provide the most accurate results in terms of bearing capacity and uncertainty quantification. This method offers a promising approach that leverages machine learning to integrate simulation and experimental data, thereby improving large-scale equipment simulation without increasing computational costs.

     

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