基于改进条件邻域熵的接头疲劳寿命影响因素分析

Analysis of factors affecting fatigue life of welded joints based on improved conditional neighborhood entropy

引入监督策略对粒化条件邻域熵进行改进,提出基于监督粒化的条件邻域熵属性约简算法.在4个公开的数据集上对算法性能进行了试验.结果表明,所提出的算法具有较高的约简率和分类准确率.建立了基于该算法的铝合金焊接接头疲劳寿命影响因素分析模型,并基于互信息理论分析了焊接接头疲劳寿命各影响因素之间的耦合关系.分析结果表明,应力集中系数受接头类型与焊接方法影响最大,受焊脚长度影响最小,说明在计算应力集中系数时接头类型与焊接方法的影响需要重点考虑;等效结构应力范围对于接头疲劳寿命影响的权重为0.461 2,名义应力范围的权重为0.347 3,说明经过应力修正之后,等效结构应力范围相较于名义应力范围对接头疲劳寿命影响的权重值增加,因而能更准确的预测接头的疲劳寿命.

The supervised strategy is introduced to improve the granule conditional neighborhood entropy, and an attribute reduction algorithm based on supervised granule conditional neighborhood entropy is proposed. Experiments are carried out on four open datasets. Experimental results show that the proposed algorithm has higher reduction rate and classification accuracy. Based on this algorithm, an analysis model of the fatigue life influencing factors of aluminum alloy welded joints was established. The coupling relationship among the fatigue life influencing factors of the welded joints is analyzed by using the mutual information theory. Analyzing results show that the stress concentration factor is most affected by the joint type and welding method, and least affected by the weld leg length. It indicates that the joint type and welding method should be major considerations when calculating the stress concentration factor. The weight of equivalent structural stress range on fatigue life is 0.461 2, and the weight of nominal stress range is 0.347 3, which indicates that after stress correction, the weight of equivalent structural stress range on fatigue life of the welded joints increases compared with nominal stress range, so it can predict fatigue life of the welded joints more accurately.