泵送混凝土非定常流泵送压力动态特性研究

Study on Dynamic Characteristics of Unsteady Flow Pumping Pressure of Pumped Concrete

泵送混凝土泵送压力的计算对泵车的设计与施工有很大参考意义,对分析泵车振动机理及振动动态特性变化起着至关重要的作用。由于混凝土在管道中流动的复杂性,目前国内外计算压力损失时,更多关注的是压力损失的大小,忽略了压力损失随时间的动态变化。本文分析了泵送混凝土在管道中流动时的流动特性,在混凝土在管道中作定常流动时压力损失计算经验公式的基础上,建立了混凝土非定常流动的运动方程,利用傅里叶级数表征混凝土泵送速度模型,从而得到了泵送压力随时间变化的动态特性曲线,通过实例与测试结果进行了对比分析,验证了本文方法的正确性,为混凝土泵车动态特性分析提供了理论基础。

The calculation of pumping concrete pumping pressure has great reference significance for the design and construction of concrete pump truck,and plays an important role in analyzing the vi-bration mechanism and vibration dynamics of concrete pump trucks.Due to the complexity of concrete flow in the pipeline,when calculating pressure loss at home and abroad,more attention is paid to the magnitude of pressure loss,ignoring the dynamic change of pressure loss with time.In this paper,the flow characteristics of pumped concrete flowing in the pipeline are analyzed.Based on the empirical formula for calculating the pressure loss during steady flow of concrete in the pipeline,the equation of motion of unsteady flow of concrete is established.The Fourier series is used to characterize the concrete pumping speed model,and the dynamic characteristic curve of pumping pressure with time is obtained.The comparison between the example and the test results demonstrates the correctness of the method in the paper and provides a theoretical basis for the analysis of the dynamic characteristics of the concrete pump truck.