直板叶片振动响应试验的相似关系确定方法

Determination Method for Similarity Relationship of Straight-plate Blade Vibration Response Test

针对直板叶片弹性振动响应相似问题,基于板壳振动理论,根据方程分析法得到叶片振动响应相似关系,并采用ANSYS有限元软件对原型与模型进行数值仿真对比。基于振动响应的机理分析,通过相似关系得到载荷加载时间等参数,结合有限元预测系数法对模型叶片振动响应时程曲线进行校正。针对不完全几何相似关系,通过敏感性分析法确定畸变模型与原型在固有频率、加载时间以及位移等参数下的相似比。结果表明:通过相似理论结合有限元预测系数法可以提高模型时程曲线预测精度;采用敏感性分析法得到了振动响应不完全几何相似关系,解决了大时间相似比下的响应预测问题。为实际工程中大型复杂结构的相似模型设计奠定了理论基础。

Aiming at the similarity problem of the elastic vibration response of the straight-plate blade,based on the plate-shell vibration theory,the similarity relation of the vibration response of the blade was obtained by the equation analysis method.Comparison of numerical simulation between prototype and model was carried out by ANSYS finite element software.Based on the mechanism analysis of vibration response,the loading time and other parameters were obtained by similarity relation.The time curve of vibration response of model blade was corrected by finite element prediction coefficient method.For the incomplete geometric similarity relationship,the sensitivity analysis method was used to determine the similarity ratio between the distortion model and the prototype under the parameters of natural frequency,loading time and displacement.The results show that the prediction accuracy of the model time curve can be improved by combining the similarity theory with the finite element prediction coefficient method.The incomplete geometric similarity relation of vibration response is obtained by sensitivity analysis method,and the problem of response prediction under large time similarity ratio is solved.It lays a theoretical foundation for the similar model design of large and complex structures in practical engineering.