火箭橇对飞机、导弹、航空飞行器等速度与加速动态试验测试至关重要。采用有限元分析预示试验工况是成功开展火箭橇试验不可或缺的部分。随着火箭橇试验速度的不断增加,对有限元模型的精度要求也相应提高。因此,需要提升火箭橇的整体建模技术,以满足各类试验需求。为更准确地预示火箭橇试验的动态响应,构建了基于薄壁结构的高精度模型,采用壳-实体混合单元实现薄壁结构的精确建模,并利用满足位移协调的网格,确保壳-实体单元间的位移一致性和载荷的准确传递,以提高模型的计算精度和稳定性。高、低速火箭橇运行过程的仿真结果表明,混合单元的薄壁结构在振动响应预示方面优于实体单元结构。试验结果与仿真结果的对比显示,在研究范围内,该模型的误差满足试验需求,其有效性和可靠性得到了验证。因此,采用混合单元薄壁结构进行建模能够更准确地预测火箭橇的动态响应。这一建模方法为火箭橇结构的设计和优化提供了重要技术支持,对提升火箭橇性能具有重要意义。

Rocket sleds are essential for dynamic testing of speed and acceleration in aircraft,missiles,and aerospace vehicles.Finite element analysis (FEA) is a critical component in predicting test conditions for successful rocket sled experiments.As the speed of rocket sled tests increases,the accuracy requirements for FEA models also escalate.Consequently,it is necessary to advance the overall modeling techniques of rocket sleds to meet diverse test requirements.To more accurately predict the dynamic response of rocket sled tests,a high-precision model based on thin-walled structures has been developed.The proposed model employs a shell-solid mixed element approach for precise modeling of thin-walled structures and utilizes displacement coordination methods to ensure displacement consistency between shell and solid elements.This methodology ensures the accurate transfer of loads,thereby enhancing the calculation accuracy and stability of the model.Simulation results of high- and low-speed rocket sled operations indicate that the thin-walled structure of mixed elements outperforms the solid element structure in predicting vibration responses.A comparison between experimental and simulation results shows that,within the study range,the model’s error meets test requirements,and its effectiveness and reliability are validated.Thus,modeling with a mixed element thin-walled structure can more accurately predict the dynamic response of rocket sleds.This approach provides critical technical support for the design and optimization of rocket sled structures and is significantly important in enhancing rocket sled capabilities.