ABSTRACT

A closed-form analytical solution procedure is proposed to solve the coupled fluid-structure interaction (FSI) equations that involve the first-order Doubly Asymptotic Approximation (DAA₁) formulation. An efficient method comprised of the nonstandard finite difference (NSFD) scheme is applied. First of all, analytical equations are developed to analyze the response of a rigid mass-spring oscillator in an air-backed condition when it is subjected to a plane shock exponential wave coming from a far-field underwater explosion. After validating the results with LS-DYNA/USA (DAA₁), these equations are extended to determine the response of a two-dimensional, simply-supported rectangular plate, and then tested on the isotropic and orthotropic plates within a small deflection regime. Parametric studies are also performed by varying the load decay times, peak pressures, as well as the aspect ratios of the plate. Finally, the advantages and limitations of the proposed formulae are exposed along with suggestions for the future work.

摘要

提出了一种封闭形式的解析求解程序来求解涉及一阶双渐近近似 (DAA ₁ ) 公式的耦合流固耦合 (FSI) 方程。应用了由非标准有限差分 (NSFD) 方案组成的有效方法。首先，建立了解析方程来分析刚性质量弹簧振荡器在气垫条件下受到来自远场水下爆炸的平面冲击指数波的响应。使用 LS-DYNA/USA (DAA ₁₎验证结果后)，这些方程被扩展来确定二维简支矩形板的响应，然后在小偏转范围内的各向同性和正交各向异性板上进行测试。还通过改变负载衰减时间、峰值压力以及板的纵横比来执行参数研究。最后，揭示了所提出公式的优点和局限性以及对未来工作的建议。