液体火箭发动机阻尼机架减振特性研究

Study on vibration attenuation of damping frame for liquid rocket engine

对具有橡胶——惯性结构的火箭发动机机架简化模型中动态载荷传播特性进行了研究。机架内动态载荷在依次通过橡胶--惯性结构粘贴位置时,携带的部分动能传递到橡胶材料内,导致机架内应力幅值显著低于能量交换前的应力。通过分析橡胶材料内外表面的速度,发现速度差引起了橡胶阻尼材料沿轴向发生剪切加载和卸载过程,并导致机架传递到橡胶材料的动态能量发生剪切变形的过程中被耗散吸收;此外,机架内动态载荷大小与机架内质点速度的变化量有关,机架内质点动能减小及运动速度降低是引起机架动态载荷幅值降低的根本原因。

Dynamic loading transmitting characteristics in simplified frame model with rubberinertia structure used in liquid rocket engine was studied in this paper. When the dynamic loading transmits across the place pasting the rubber-inertia structure, a part of kinetic energy of the loading in the frame was transferred into the rubber. As a result, the dynamic nominal stress in the frame was sharply reduced. It was found that loading and unloading processes in the rubber material were induced in turn by the velocity differences between the outer and inner surfaces, during which the dynamic energy absorbed by the rubber was quickly dissipated. In essence, the dynamic loads depending on the changes of the particle velocity in the flame are reduced by the kinetic energy decrease of the flame particle.