【摘要】 为了解决医学超声探测的动态计算机仿真问题,将计算电磁学的时域有限差分(FDTD)方法应用于弹性机械波的模拟.建立了模拟弹性波时的有限差分模型,给出了弹性媒质运动学方程的FDTD离散形式,提出了复杂媒质边界的处理方法,用完全匹配层吸收边界截断计算区域.数值实验验证了上述模型和计算方法的有效性.更多还原

【Abstract】 In order to obtain the dynamic computer model of the medical ultrasonic exploration,an innovative numerical method,the finite-difference time domain method, which has been widely used in computational electrodynamics,is applied to solving the elastic mechanical waves in time domain.The model of the finite-difference on elastic waves has been set up based on the (Yee′s) algorithm. The governing equations of the motion and stress-strain relation coming from a first order stress-velocity formula are obtained, which are discretized using centered difference approximation. The processing method of complex media across borderline is discussed. A perfectly matched layer absorbing boundary condition to break computational area is presented. Numerical experiments proved the effectiveness of the proposed algorithm.更多还原