基于等效梁模型的运载火箭动力学特性仿真预示研究

针对运载火箭动力学特性仿真预示问题,提出了一种基于等效梁模型,其是可考虑贮箱内液体推进剂影响高效、准确的仿真预示方法.应用等效厚度法建立了运载火箭的等效梁模型,并将运载火箭精细有限元模型的模态分析结果作为目标,通过有限元模型修正提升了等效梁模型的精度.以某型号运载火箭为算例,应用该文方法,建立了其等效梁模型,并基于集中质量法和耦合质量法两种液体推进剂等效方法对其进行了考虑贮箱内液体推进剂影响的动力学特性预测,比较了两种方法的分析结果.

Dynamic Characteristics Prediction of Launch Vehicles Based on the Equivalent Beam Model

An efficient and accurate method was proposed for dynamic characteristics prediction of launch vehicles based on the equivalent beam model,with which the influence of liquid propellants can be considered.The equivalent beam model for the launch vehicle was established based on the cross-sectional area equivalence principle,and improved through model updating against the natural frequencies and mode shapes of the fine finite element model.The present method was validated through computation of a certain type of launch vehicles.A highly representative equivalent beam model for the launch vehicle was established.The dynamic characteristics of the launch vehicle were predicted based on the equivalent beam model under the influence of liquid propellants in 2 ways of the lumped mass method and the coupled mass method,and the results were compared.