基于振速测量单全息面直接声场分离方法

摘 要：为了更精确的分离质点振速，以波叠加法作为声场分离算法基础，提出单全息面测量振速直接声场分离方法。建立了单面振速测量声场分离模型，并推导了理论计算方法，通过数值仿真，分析算法的计算精度，验证了该方法可以有效分离声场。然后对比本文分离方法和单面声压测量声场分离方法分离简单源和脉动声源的误差，结果表明：单面振速测量的直接声场分离方法可以有效分离目标声源，而且可以获得更高的振速分离精度。

Effect of Moving Loads Speed on Dynamic Response of Bridge at the Center of Span

A simply supported beam bridge model with time-varying moving load on is established. The effect of moving load speed is considered. The vibration equation in a matrix form is presented. Adopting the powerful MATLAB code, a re-developed function based on ODE solver is programmed for analysis of dynamical response problems of the time-varying systems, such as vehicle-bridge coupling vibration problems. Analytical results show that as the maximal deflection occurs, moving load does not always locate at mid-span but varies regularly with moving load speed. As the moving load speed increases, the maximal deflection at the mid-span increases fluctuantly. And the fluctuation period and amplitude increase regularly.