火箭捆绑机构热力耦合模型修正与虚拟验证方法

Model updating and virtual verification for launch vehicle strap-on thermal mechanical structures

在缺少试验数据的情况下,为得到精确的火箭捆绑机构热力耦合有限元模型,提出了一种考虑建模不确定性的模型修正与虚拟验证方法。所提出的方法充分利用前期型号已有的试验数据,对尚无试验数据的在研新型号火箭捆绑机构基于通用化摩擦热理论公式进行虚拟映射、验证及修正。首先,建立前期型号的捆绑机构有限元模型,基于已有试验数据,使用贝叶斯修正算法对有限元模型进行修正;然后,建立通用化摩擦热理论模型并标定其中的待定系数,使理论模型与有限元的计算结果一致;最后,建立在研型号的有限元模型,以标定后的理论计算值为依据,验证并修正在研型号的有限元模型。将该方法用于缺少试验数据的某新型火箭捆绑机构的数字化建模及验证问题,结果表明,修正后的有限元模型具有较高的精度及可靠性。

Facing the lack of experiment data,a model updating and virtual verification method considering modelling uncertainty wasproposed to obtain an accurate thermal-mechanical coupling finite element model(FEM)for launch vehicle strap-on structures.The proposed method makes full use of the experiment data of previous models and enables the new developing model without any experiment data,through the virtual mapping,verification and calibration based on the generalized theoretical model of friction heat.Firstly,the FEM of previous modelswasestablished and calibrated through the Bayesian updating framework.And then,the undetermined coefficients in theoretical model was determined to reduce the discrepancy between theoretical value and simulation result.Finally,the FEM of the new developing model was verified and calibrated based on the theoretical model.The proposed method wasperformed to solve digital modeling and verification problem of a novel developing strap-on structure without sufficient experiment data and the result shows the calibrated FEM has higher accuracy and reliability.