基于ADAMS的绳牵引并联支撑系统动力学建模

Dynamic Model of Wire-driven Parallel Suspension System Based on ADAMS

为了实现对低速风洞强迫振荡试验绳牵引并联支撑系统的精确控制,需要建立精确的动力学模型,分析系统的振动特性,避免共振。首先,提出适合低速风洞绳牵引并联支撑系统的线性弹簧理论,应用动力学分析软件ADAMS搭建动力学三维模型;其次,通过对系统进行振动分析,得到系统固有频率满足强迫振荡试验要求的弹簧参数;然后,对系统进行受迫振动分析,结果表明系统符合振动规律,验证了系统建模的正确性;最后,将每根绳索离散为10段线性单元,并对系统进行模态分析,发现离散前后系统的固有频率值相近似,且满足强迫振荡试验要求,说明采用线性弹簧理论建立绳索动力学模型是可行的,为了简化建模,无需将绳索离散化。

To obtain an accurate dynamic model of wire-driven parallel suspension system in low-speed wind tunnels, the study was made to realize accurate control in forced oscillation experiments as well as accurate analysis of vibra tion characteristics to avoid resonance frequencies. Firstly, an approach for modeling of wires dynamics considering the effects of structural elasticity was presented, while the wires were regarded as linear springs, and a three dimen- sional dynamics model was built in professional dynamics analysis software ADAMS. Secondly, a series of approp- riate spring parameters were set by normal mode analysis in which natural frequencies met the requirements of forced oscillation experiments. Then the forced vibration analysis results was reached to indicate the system＇s following the law of vibration, thus the system modeling was well verified. Finally, each wire was divided into 10 linear elements, and the natural frequencies were obtained. The two groups of natural frequencies appeared almost the same, and also satisfied the requirement of the forced oscillation experiment. The results show the modeling dynamics of wire- driven parallel suspension system in low-speed wind tunnels with the linear springs is feasible, which suggest no need to disperse wires to simplify the wires dynamics model.