【摘要】 研究三维时域有限元-边界元混合方法中奇异积分的计算。将其中的一些积分进行等价变形以降低奇异性。并给出了积分等价变形过程中所遇到的数值错误的一种解决方法,这一数值错误与时域有限元-边界元方法中的固有处置有关。讨论了频域中格林函数奇异点提取法推广应用于时域混合方法中奇异积分的计算,指出,频域中奇异点提取法的一些处理不适宜于时域奇异积分。数值实验检验了所给处理方法。更多还原

【Abstract】 The calculation of singular integrals arising from 3-D time domain finite element-boundary element method is invesitigated. First, equivalent transformation technique is applied to reduce the singularities of some integrals, and a remedy is presented for the numerical error encountered in this course, which essentially may be attributed to the inherent routine with the time domain finite element-boundary element method. Then, the singularity extraction technique used in frequency domain is extended to the calculation of the singular integrals with the time domain finite element-boundary element method, where some treatments used in frequency domain are not preferable for the case of time domain. Finally, the proposed scheme for the calculation of singular integrals with time domain finite element-boundary element method is verified by numerical tests.更多还原