针对某多喷嘴引射器在脉动载荷作用下的动力学响应预测问题,对其有限元模型进行了修正,减少了材料属性、边界条件等对计算结果的影响.首先开展了引射器有限元模态分析,获得了初始模态分析频率;采用了多点激励多点响应锤击法进行了模态试验,获取了试验模态频率;基于有限元模型进行了误差分析,确定了材料密度、弹性模量、质量点质量等修正参数,通过中心复合设计方法确定了样本空间,构建了多目标响应面并对待修正参数进行了约束优化,得到了修正参数的最优解;最后,使用修正后的参数进行了有限元分析,获得了修正后的模态分析频率,并通过动力响应计算进行了模型确认.研究结果表明:修正后模态分析频率与模态试验频率(前三阶)误差均值由修正前的8.01%减小到2.81%,该修正方法能够显著提高有限元模态分析精度.%Aiming at the problems that prediction of the dynamic response of a multi-nozzle ejector under the action of pulsating load, the fi-nite element model was updated to reduce the influence of material properties and boundary conditions on the calculation results. Firstly, the finite element modal analysis of the ejector was carried out to obtain the initial modal analysis frequency. Secondly, the hammering modal test on ejector was done using multi-input multi-output analysis method to get the modal test frequency of ejector. Thirdly, based on the finite ele-ment model error analysis, the correction parameters such as material density, elastic modulus and quality of mass-point were determined. After the sample space was determined by the central composite design method, the multi-objective response surface was constructed and used to obtain the optimal solution of the correction parameters. Finally, the optimal correction parameters were used for finite element analysis to obtain the corrected modal analysis frequency and dynamic response under the real load. The results indicate that the error of the first three modes between the corrected modal analysis frequency and the modal test frequency is reduced from 8. 01% to 2. 81%, so the updating method can significantly improve the precision of the finite element modal analysis.
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