arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2409.13397math.NAcs.NA
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线性和非线性动力学的高阶隐式时间积分方法及加速度的高效计算

A high-order implicit time integration method for linear and nonlinear dynamics with efficient computation of accelerations

Daniel O'Shea, Xiaoran Zhang, Shayan Mohammadian, Chongmin Song

AI总结:

提出一种自启动高阶隐式时间积分算法族,无需质量矩阵分解即可高效计算加速度,适用于线性和非线性动力学,具有可控数值耗散,在非线性问题中保持高收敛阶和精度,显著优于商业软件常用的二阶方法。

摘要:

本文针对线性和非线性瞬态问题,提出了一种具有可控数值耗散的自启动高阶隐式时间积分格式族算法。本工作基于作者先前关于弹性动力学的研究,提出了一种新算法,该算法无需对质量矩阵进行分解,从而有利于求解非线性问题。改进后的算法通过向量运算(无需额外求解方程)直接获得与位移和速度同阶精度的加速度。非线性通过在时间步内进行数值积分来处理,以达到所需的精度阶数。新算法完全保留了先前工作的优良特性:1. 精度阶数不受外力和物理阻尼的影响;2. 算法中的数值耗散由用户指定参数控制,从而产生从完全无耗散的A-稳定到L-稳定的格式;3. 有效刚度矩阵是质量、阻尼和刚度矩阵的线性组合,如同梯形规则。所提出的算法被证明能够复现先前工作中线性问题的数值结果。本文还给出了线性和非线性振动及波传播的额外数值算例。值得注意的是,所提出的算法在非线性问题上表现出与线性问题相同的收敛阶数,且精度非常高。商业软件中常用的二阶时间积分方法对于一类常见的波传播问题会产生严重污染的加速度响应。本文提出的高阶时间积分格式在抑制虚假高频振荡和产生可靠可用的加速度响应方面表现明显更好。

英文摘要:

An algorithm for a family of self-starting high-order implicit time integration schemes with controllable numerical dissipation is proposed for both linear and nonlinear transient problems. This work builds on the previous works of the authors on elastodynamics by presenting a new algorithm that eliminates the need for factorization of the mass matrix providing benefit for the solution of nonlinear problems. The improved algorithm directly obtains the acceleration at the same order of accuracy of the displacement and velocity using vector operations (without additional equation solutions). The nonlinearity is handled by numerical integration within a time step to achieve the desired order of accuracy. The new algorithm fully retains the desirable features of the previous works: 1. The order of accuracy is not affected by the presence of external forces and physical damping; 2. numerical dissipation in the algorithm is controlled by a user-specified parameter, leading to schemes ranging from perfectly nondissipative A-stable to L-stable; 3. The effective stiffness matrix is a linear combination of the mass, damping, and stiffness matrices as in the trapezoidal rule. The proposed algorithm is shown to replicate the numerical results demonstrated on linear problems in previous works. Additional numerical examples of linear and nonlinear vibration and wave propagation are presented herein. Notably, the proposed algorithms show the same convergence rates for nonlinear problems as linear problems, and very high accuracy. Second-order time integration methods commonly used in commercial software produce significantly polluted acceleration responses for a common class of wave propagation problems. The high-order time integration schemes presented here perform noticably better at suppressing spurious high-frequency oscillations and producing reliable and useable acceleration responses.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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