Abstract In this paper, Finite Element-Indirect Boundary Element (FE-IBE) coupling approach based on the Isogeometric Analysis (IGA) framework is proposed to deal with Acoustic-Structural Interaction (ASI) problems. Numerical simulation of thin-walled structures is carried out by using isogeometric Reissner-Mindlin shell theory. The isogeometric indirect boundary element method (IBEM) is used to simulate the fluid domain, and the coupling formula is established by connecting the primary variables. IBEM contains information on both sides of the boundary. Naturally, FE-IBE coupling method inherits these attractive features. FE-IBE coupling method has a wide application prospect. In general, it can not only deal with the common problems, but also solve the problems that Finite Element-Direct Boundary Element (FE-DBE) coupling method cannot handle, such as the opened boundary problems, whose inner and outer boundaries contact the liquid. In order to further expand its application range, based on the universality of the primary variables in IBEM, a more generalized coupling formula is derived to solve the hybrid problems with both the closed and opened boundaries. Numerical examples with analytical solution verify the reliability and stability of the proposed IGA FE-IBE coupling method, and two complex problems in aerospace engineering and ocean engineering are studied in detail.

中文翻译：

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具有复杂耦合模型的声-结构相互作用问题的 3D 等几何 FE-IBE 耦合方法

摘要 本文提出了基于等几何分析（IGA）框架的有限元-间接边界元（FE-IBE）耦合方法来处理声-结构相互作用（ASI）问题。利用等几何Reissner-Mindlin壳理论对薄壁结构进行数值模拟。采用等几何间接边界元法（IBEM）模拟流体域，通过连接主变量建立耦合公式。IBEM 包含边界两侧的信息。自然，FE-IBE 耦合方法继承了这些吸引人的特点。FE-IBE耦合方法具有广泛的应用前景。总的来说，它不仅可以处理常见问题，还可以解决有限元-直接边界元（FE-DBE）耦合方法无法处理的问题，例如开放边界问题，其内边界和外边界接触液体。为了进一步扩大其应用范围，基于IBEM中主变量的普遍性，推导出更广义的耦合公式来解决封闭边界和开放边界的混合问题。数值算例与解析解验证了所提出的IGA FE-IBE耦合方法的可靠性和稳定性，并详细研究了航空航天工程和海洋工程中的两个复杂问题。