结构动力模型试验相似理论及其验证

Validation of similitude laws for dynamic structural model test

通过几何比尺为2的两个有机玻璃模型的结构动力试验,验证了结构动力模型试验的弹性相似律和弹性力—重力相似律。得到了以下结论:(1)大小模型频率符合相似律,一阶频率误差为2.7%、4.1%,二阶频率误差为0、6.05%。弹性相似律比弹性力—重力相似律更适合于频率预测的试验。(2)大小模型的加速度、应变符合相似律,弹性相似律的加速度误差为-1.55%～8.75%,应变误差为0.377%～7.297%。弹性力—重力相似律的加速度误差为3.07%～4.158%,应变误差为6.849%～12.959%。(3)不同相似律大小模型的时间比尺吻合很好。加速度与应变时程曲线的波形一致,既无漏峰也无错峰。

Based on the shaking table test of two perspex model that the scale factor of geometry is 2.0, the similitude laws between the prototype and the model for dynamic structural model test have been validated. The similitude laws include elasticity similitude law and elasticity-gravity law. The conclusions are (1) The scale factor of frequency between large and small perspex model test accord with similitude law basically. The error of primary frequency is 2.7% or 4.1%, the error of the second frequency is 0 or 6.05%. The elasticity similitude law is better than elasticity-gravity law for predict the prototype frequency form model test result. (2) The scale factors of accelerations and strains also accord with similitude law basically. Using elasticity similitude law, the errors of acceleration is form 1.55% to 8.75%, the strain errors is form 0.377% to 7.297%. Using elasticity-gravity similitude law, the acceleration errors is form 3.07% to 4.158%, the strain errors is form 6.849% to 12.959%. (3) The acceleration history and strain history between large and small model accord with scale factor of time completely in either elasticity similitude law or elasticity-gravity law. The peaks and vales of the both histories agree with each other.