Decreasing stress in a part or piece of equipment especially in a stress concentration point without increasing thickness or using stronger material is always an interesting issue for design engineers. In this paper, piezoelectric patches were used for stress concentration reduction around various hole sizes in thin-walled cylindrical shells subjected to internal pressure. Applied voltage to piezoelectric patches induces strain on both patch and part and alters stress flow on the part, leading to new distribution of stresses. Three dimensionless effective parameters that include hole and shell diameters as well as shell and piezo patch thicknesses were selected in this investigation. Ant colony optimization was utilized, and attachment of optimal arrangements of piezoelectric patches was derived for various numbers of piezoelectric patches. Using finite element analysis, it was shown that various combinations of these dimensionless parameters (R/t, tp/t and d/D) have different effects on reducing the maximum stress around the hole and up to 20% reduction on maximum stress was achieved during this research. Experimental tests were finally performed to verify finite element results.

中文翻译：

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使用压电贴片降低承受内压的薄壁圆柱体孔周围的应力集中

在不增加厚度或使用强度更高的材料的情况下降低设备部件或部件中的应力，尤其是应力集中点的应力，一直是设计工程师关注的问题。在本文中，压电贴片被用于在承受内压的薄壁圆柱壳中减少各种孔径周围的应力集中。向压电贴片施加电压会在贴片和零件上引起应变，并改变零件上的应力流，导致应力的新分布。在本次调查中选择了三个无量纲有效参数，包括孔和壳直径以及壳和压电贴片厚度。利用蚁群优化，并针对不同数量的压电贴片推导出压电贴片最佳布置的附着。使用有限元分析表明，这些无量纲参数（R/t、tp/t 和 d/D）的各种组合对降低孔周围的最大应力具有不同的影响，并且最大应力降低了 20%在这项研究中。最后进行了实验测试以验证有限元结果。