基于模态试验和冲击响应试验的模型动力学参数修正

Modification of dynamic parameters of impact model based on modal test and shock response test

为通过数值仿真计算方法准确预测冲击响应,基于模态试验和冲击响应试验,对响应板的碰撞冲击过程进行动力学参数修正。模态试验过程,通过响应面优化的方法对响应板的弹性模量、泊松比、厚度参数进行优化,优化后的固有频率计算值相对误差在±2%以内。冲击响应试验过程,冲头冲击高度6.3 cm条件下,对试验和数值仿真的响应谱曲线进行误差评价;基于响应谱各分析频率点均方根误差最小的优化目标,通过曲面拟合得到最优的质量阻尼系数和刚度阻尼系数。动力学参数修正后的模型在3个不同冲击高度条件下的冲击响应谱预测中,大部分频率段的误差在±6 dB以内,显著提高了预示精度。

In order to accurately predict the shock response spectrum through the numerical simulation method,in this paper,based on the modal testing and the shock response spectrum testing,the dynamic parameters during the impact process of the response plate are modified.During the modal testing,the response surface optimization method is used to optimize the elastic modulus,the Poisson’s ratio,and the thickness of the response plate.The relative errors of the optimized natural frequency are better than 2%.During the shock response testing,when the punch height is 6.3 cm,the response spectrum curves obtained by the testing and by the numerical simulation are used to evaluate the relative error.To minimize the root mean square error of the shock response spectrum at the analysis frequency points,the best fitted mass damping coefficient and the stiffness damping coefficient are obtained after the curled surface fitting.With the simulation model and the modified dynamic parameters,the error of the response spectrum prediction is within±6 dB for three different punch heights,which shows that the dynamic parameter optimization method is applicable.