阻尼受击板的时域建模及声音合成

Time-domain simulation and sound synthesis of damped impacted plates

为满足声源辨识中对合成冲击声的迫切需求,建立了球-板撞击的时域模型,提出一种时域快速求解方法,并进行了实验验证.首先给出一种将时域有限差分法(FDTD)和模态展开法(MEM)相结合的时域混合方法,求解板的振动方程,并解决了混合方法中MEM的模态截断和初值问题,及两种方法中阻尼的一致性问题;随后,给出了简支矩形板的冲击声计算结果,通过与FDTD方法的运算量进行对比,验证了混合方法的高效性;最后,针对自由边界下的L形板进行了实验验证.结果表明,与传统FDTD方法相比,时域混合方法在保证合成冲击声精度的前提下可将计算效率提高100至1200倍。

In order to meet the strong demand of synthesis impact sounds in sound source identification, a ball-plate collision model and corresponding fast computing method are given in time-domain. Firstly, a hybrid method combined finite-difference time-domain （FDTD） with modal expansion method （MEM） is used to solve the vibration equations of the plate. Secondly, some key issues for the hybrid method are considered, including modal truncation and initial value problem of MEM and consistency of different damping representation between two methods. Finally, the computing results using the hybrid method and that of FDTD for simply supported rectangular plate are compared, and the recording experiment for the L-shaped plate under free edges conditions is carried out. The results show that, comparing with FDTD the computing efficiency of the hybrid method is improved by 100 to 1200 times without loss of accuracy.